"The fate and survival of the adult will be rhaped by

the character structures of the neonates. Birth and the

f i r s t few days were well known t o be the most decisive

period of development. It is assumed that a newborn infant

i s an unwrapped highly plastic bioenergy system which will

be influenced by a multiple o f environmental impacts. The

greates t difficulty would be the lack o f knowledge about the

bioenergetic expression in the new born. It i s now known how

the neonate fee ls or how it experiences its first weeks of

l i f e ourside the uterus, However with careful observation

the problems would turn up rap id ly and clearly and would

eventually be solved".

Today man has become ever mare conscious of the manner

in which the environment is being polluted by a v a r i e t y of

pest icides that may cause undesirable hazards t o p l a n t s ,

animals or even t o himself. Pesticides by definition kill

p e s t s , but no pesticide is a specific poison t o any pest and

thus there is every risk of death or sublethal effect on

other non-target organisms inhabiting the same ecosystem.

Pesticides or agrochemicals are the chemicals designed to

combat the a t t a c k s of various pests on agricultural and

horticultural crops. They fall into three major classes,

insecticides, fungicides and herbicides. There are also

rodenticides (for control of vertebrate pests), nematicides

( t o kill microscopic eel worms), molluscicides ( t o kill

slugs and snails) and acaricides ( t o kill m i t e s ) .

Pesticides may also be divided into two main types,

namely contact or non-systemic pesticides and systemic

pesticides. Many of the recent pesticides are systemic in

character and can effectively penetrate the cuticle and move

through vascular system. The prodigious growth of the

pesticide industry during the l a s t f i v e decades has played a

major role in the development of agriculture and forms an

integral component of the "Green revo\utionn (Wilkinson,

1976) . Pesticides have also brought spectacular social and

2

sconomic gain8 t o large areas of the world as a result of

their role in thr eradicat ion of malaria and other

arthropod-born diseases (Wilkinson, 1976). But in spite of

these benefits the wide spread use o f insect ic ides a lso

created some serious problems. The hazards o f using

chemical pesticides have increased in recent years with the

sharp rise in consumption by a g r i c u l t u r e industry households

and Government ( M i l k i n s o n , 1976) .

The use of pesticide attained prominence only i n the

post-war p e r i o d . The era of s y n t h e t i c organic pesticides

began around 1940. Methyl parathion was introduced in 1949.

I t proved to be more useful than ethyl parathion because of

its less toxicity to man and broader range of insect c o n t r o l

(&le ln ikov , 1971 1 .

Since organochlorine pesticides are extremely long

persistent, the Less persistent organaphosphorous

insecticides are now being widely used to augment the

agricultural protection. Among the organophosphorous

compounds, methyl parathion is very much pre ferred because

of i t s relatively low mammalian toxicity (Melnikov, 1971).

I n India methyl parathion is mainly used for c o n t r o l o f rice

stem borers, fruit worms, t e a Leaf worms and also as

sanitary, veterinary and f o r e s t insecticides. This wide

a p p l i c a b i l i t y of pesticide has led t o the problem of

pollutian o f aquatic environment by residues from surface

run off water and endangered the life of non-target aquatic

animals l i k e fish, crabs and snails (Shankara Naidu, 1985).

The incidence of p e s t i c i d e poisoning i n the t h i r d world

has assumed a la rming proportions following the intensive and

i n d i s c r i m i n a t e use of a wide range of "highly viciousi i

agrochemicals designed t o boost the green revolution. I t h a s

been e s t i m a t e d that nearly one million tonnes of organic

pesticides enter the environment annual- Xy i n the world

(Vishweswaraiah - et &., 1 9 7 5 ) . In Indfa the consumption of

pesticides has increased from 1 S O tonnes in 1953 t o 6 ,200

tonnes i n 1977 (Raghavan, 1979 ) . A recent field study by the

WHO r e v e a l s t h a t o n an average one person is poisoned every

minute by pesticides in the developing world. Of the five

lakh cases of pesticide poisoning r e p o r t e d each year from

the third world, n e a r l y 10,000 a r e reported as f a t a l .

Pesticides e i t h e r banned or severely r e s t r i c t e d i n the

U.S. and Western European countries are being used in the

th ird world for agricultural and public health purposes. For

instance, in Egypt, phosrel a highly toxic pesticide

manufactured by American multinational velrlcol corporation

is being used. I t caused p a r a l y s i s among hundreds of water

buffaloes. I n Iraq, 2 1 persons died a f t e r consuming wheat

heavily sprayed with a mixture of DDT and malathion. About

10 outbreak. of TOCP poisoning have been reportedw. ~ h c

biggest one occurred i n 1930 i n USA where more than 10,000

people were s t r icken with a f l a c i d paralysis (So c a l l e d

ginger paralysis) of the lower limit. The recent out break

took place i n Morocco 1959 from cooking oil contaminated

with the lubricated oil of turbojet a i r c r a f t eng ines . In

Pakis tan (1976) 2 ,500 people died due t o the

~rganophosphorous impurities during malaria control

operation (Naiyara Yasmeen, 19891.

India is mainly an agricultural country and nearly 80%

of the populatlon belong to t h e rural areas. Many of them

are illiterates and they use pesticides i n d i s c r i m i n a t e l y .

Thus pesticides have posed a great danger to p u b l i c hea l th

i n Ind ia .

Pesticides can came in contact with man and domestic

animals by acc identa l encounter or as residues in food,

water and a i r . In the year 1958 a t least 104 persons died i n

K e r a l a state due to the consumption of food products

contaminated with organophosphorous chemicals due to

leakages Prom the containers in a s h i p (Shinde, 1979) . I n

1962, f a t a l poisoning due t o parathion t o x i c i t y had occurred

in a fac tory i n Bombay because of skin absorption and

inhalation (Shinde, 1979). In 1964 many persons suffered

f t o m toxic effects of endrin of which one died due to

conrunptlon of contaminated rice. By taking food on banana

leaves contaminated with copper sulphate 160 persons

suf fered from retching and vomiting i n Kerala s t a t e (Shinde,

1979). In July 1976 an outbreak of epilepsy among 150

persons Fn U t t a r Pradesh was found to be due to consumption

of contaminated wheat (The Hindu, 1976) . The catastropic

accident a t Union Carbides, Bhopal plant in December 1984,

in which the Lethal methyl isocyanate gas (MIC leaked,

kilting and cripp!ing thousands, has put into sharp focus,

the dangers and perils assocLated with agrochemicals (The

Hindu, 1984). In February 1977 , villagers in the remote

h i l l y t racks of Karnataka i n Ind ia , were bedridden w i t h a

strange type of crippling disease called the 'Handigodu

syndrome' in local paralance a f t e r consuming crabs exposed

to parathion and endrin (David Bull , 1982).

"The Handigodu syndrome ofkKarnataka, India" (Hindu, 1977 ) .

A s i z a b l e number of men, woaen and children belonging

particularly to scheduled caste agricuLtura1 labouring

families in the village Handigodu, Malnad d i s t r i c t ,

Karnataka s t a t e , Sagar in Shimoga d i s t r i c t and Balchonnur fn

Chikmagalur d i s t r i c t in India were attacked by this horrible

bone d i s e a s e .

Based on t h e i r chemical composition, pesticides can be

broadly classified i n t o three categories (Williams, 1967).

(1) Organochlorides

(2) Organophosphates

( 3 ) Qrganocarbamates

Organophosphorous compounds represent extremely

important class of organic insecticides. Their early

development stemmed from war time research on nerve gases

for use i n chemical war force by Dr . Gerhard Schrader and

h i s team in Germany, Schradsr 11938-44) developed a ser ies

of organaphosphorous compounds like tetraethyl pyrophosphate

(TEPP) and octa methyl pyto phosphate (OMPP) (Schtadam),

parathion, paraxon. Matathian was the f i r s t example of a

wide spectrum organophosphorous insecticides having Low

mammalian taxicity. Recently other safe compaunds such as

aphicide, menazan a r e developed. Otganaphosphorous compounds

constitute a major portion of the modern synthetic

insecticides today . An import ant advantage of

organophosphorous insecticides i s that they are generally

rapidly degraded a f t e r application to non-toxic materials.

Consequently they are not persistent, like organochlorine

insecticides and therefore do not tend t o accumulate in the

envlrannent. However, these compounds are known t o cause

biochemical lesions as they are demyelinating cholinesterase

fnhibitora. They cause accumuletfon of ace ty l choline

producing characteristic cholinergic symptoms.

A 'cl688iy ~818thd thsrd (~rbup'of Lnsecticides are t h i

c.rb.mfte''amte*a firit di;c&vered by the Gcigy company in

~witssrla~d i n 1947. Carbarnates are as potent cholinesterare

inh ib i tor8 as organophosphates and a number of reviews on

insecticidal carbarnates a r e available for reference

The synthetic pyrethrolds are the primary insecticides

used for the control of many insect pests (Dowd 9

1987) . Pyrethroids were introduced in late 1970's and have

become one of the moat important group of insecticides in

the world today with global s a l e o f $680 millions i n 1983

( S c o t t and Ceorghion, 1986). Like other major classes of

insecticides, pyrethroids are also found t o interfere with

the function of the nervous system ( S m i t h and Stratton,

1987 1 .

Pestictde toxicity

Pesticides can come in contact with man and domestic

animals by accidental encounter or as residues in food,

water and a . The former route o f t e n causes acute

poisoning. Occupational exposure (eg. pesticide factory

workers and pest control operatore) usually results i n

chronic polronlng and provides rough est imates of toxicity

to humans Eor some of the pesticides. However pesticides

intake through food, water and a i r has been neglected since

the amount of tntake was thought to be insignificant,

Studies on the subtle effects of chronic exposure t o

persistent pesttcidea have began only recently.

No pesticide is specific in its act ion and the

p e s t i c i d e s vary great ly in their toxicity and persistence

(Moore, 1969). Various animals exhibit varying degrees of

susceptibility t o pesticides. Further, the t o x i c i t y of any

pesticide depends upon several biological factors like

species specificity (Henderson et &, 19601, animal wefght

and s ize (Pickering - s t G. , 19621, developmental stage

(Kamaldeep and Toor, 19771, nutritional s t a t u s (Puzynska,

19&0),physicaL and chemtcal factors like temperature, pH and

hardness of water (Henderson - e t = a 1 9 1960; Macek - et * * a 1

19691,

Watts -- et a l . (1966) reported that the route of entry

and the age of the animal influence the pesticide toxicity

in t a r g e t animals (Gaines, 1969; Kuhr and Davis, 1975) .

Anderson (1960) studied the Influence of eleven

insect ic ides (DDT, methoxychlor, chLorbenzitate, parathion,

malathion, diatinon, EPN, a l d r i n , heptachlor, dieldrin and

Endrin on Daphnia magna a crustacean. Insecticides are also

known t o affect the crabs and other related forms such as

shrimps, prawns, copepods etc. (Losanoff, 1960). From

aquatic bioassay studies of eleven pesticides by using

l a rvae 0 0 the mosquito, Streikman (1985) found that the

delayed development was a more sensltlve Indicator than

mor ta l i t y f o r detection of s i x of these pesticides. d he

ph~rmacological actions o f these carbamates (Zectran,

Carbaryl , Adicarb) and two organophosphates (Formothion and

Trichlorfon) were studied on isolated heart, medium dorsal

radula protractor muscle and rectum of the s n a i l - P i l a

plobosa, a pest of paddy crops in India. (Singh and Singh,

1979) 1

Selma - e t - a l . (1980) tested toxicity of different

insecticides on d i f f e r e n t l a r v a l in s tars of the cotton

leafwotm Spodoptera littoralis and found that the toxicity

of a pes t i c ide varies depending on the stage of life history

of the animal.

The studies of Puzynska, (1980) on rats treated with

parathion indicated that the pesticide toxicity also depends

on the nutritional s t a t u s . The studies of Indira

Chakravarthy end Renuka Sreedhar (1982) an r a t s t rea ted with

popuxur substant ia ted t h i s .

Toxicity studies were conducted in insects, fishes,

mice, humans and other animals by several workers (KolLer e t - a 1 ,= , 1976; Rainsford 1978, Cuddiny, e t a1 - * I 1979; and

Moorthy - e t a 1 1982). Rosata e t al. (1976) determAned the -- maximum to le ra ted dose (LD50) and medium effective dose

(WSO) and tha doer required t o paralyse or cause dose of

the righting ref lex for toxiferene dichloride i n sample

population. of Rherua monkeys and guinea p igs and used the

data for the computation of therapeutic index and margin of

safe ty . S L a l l a r studies on dose verses response were

conducted with sumithion on crabs (Bhagyalakshmi and Rama

Moorthy, 19801, malathion on snails (Sivaiah and Ramana Rao,

19781, 1,lndane and sumithion on snails (Madhu - et -- a 1 9 19821,

methyl parathion on fresh water muscle (Sreenivasa Moorthy,

1983) and sumithion and sevin on f i s h (Koundinya and Rama

Moorthy, 19801,

Elany workers have attempted to evaluate pesticidal

hazards on biota (Edwards, 19731. The hazards associated

with the use of the p e s t i c i d e s manifest in chronic or acute

toxicities i n man. I t was reported that insecticides are

responsible for 15,000-60,000 accidental poisoning among

American children (Anonymous, 1967). Children a r e known t o

be more susceptible t o poisoning by insectLcides than adults

(even sy/kg). S i m i l a r l y young animals and emaciated or

l a c t a t i n g animals are also more susceptible to t h e toxic

impact of pesttcides (Matsumura, 1975).

Respiratory activity of an organism has frequently been

used t o determine the extent of stress caused by

i n r e c t i c M e s (NewelL, 1973) . A sharp and substantial

increaee in the rate of oxygen consumption in fishes

(Holden, 1973) and insects (O'Btien, 1967) has been reported

on pesticide exposure. Orgenophosphorous pesticides are

known t o cause respfraCory d i s t r e s s in aquatic biota like

f i s h , creating phyaiolagical imbalance (Nagaratnamma and

Ramamurthy, 1982) . Sublethal effects of DDVP on respiratory

metrbollsm of Tilapla mossambica caused physiologiCa1

imbalance (Rath and M i s r a , 1979). Investigations on tissue

respiration in Sattherodon mossanbicus on sumithion and

sevin exposure revealed reduced oxygen uptake of various

tissues like bra in , gill, muscle, l i v e r , intest ine and

kidney (Koundinya and Ramamurthi, 19811.

Intoxication of insecticides i n general is reported t o

cause pathological and histopathological changes in cer ta in

wild species (Tucker and Leitzke, 1979). The nature of

change ranges from increase or decrease i n s ize of the organ

and weight ( Durham, 1963 1 . Couch ( 1975 1 reviewed

histopathological effects of pesticides and related

chemicals in the liver of fishes. Mccann and Jasper (1972)

reported vertebral injury in blue gills (fish) on exposure

t o s i x organophosphorous insecticides.

Toxicity induced chan&a8 i n the 8ener.l metabolism

Toxic effect cr i t er ia can range from teaporary minor

enzyme changes t o l e t h a l i t y . In peneral, chronic effects may

be ca tegor ized i n t o immediate t o x i c effects and l a t e

effects, Immediate toxic e f fec ts include behavioural

responses, biochemical l es ions , histopathological effects

and Late effects include t e r a t o g e n i c , carcinogenic and

mutagenic effects (Matsumura, 1 9 7 5 ) .

Crowda & c. (1980) studied bohavioural effects of

methyl parathion and toxaphene exposure i n r a t s which

Included, decrease in Erequency of social behaviour, feeding

and learning abilities. Christian and Bryon ( 1984 ) tested

t o x i c i t y and Lethal effects of dicrotophos on the nesting

behavtour of 5 day old European starlings Sturnas ul~aris.

Bull and Meinerney (1974) exposed Coho salmon (Oncorhynchys

Kisutch) to various concentrations of fanitrothion and

measured several behavioral alterations. Welsch and Hanselka

(1972) tested the behsvioural. effects of wethyl parathion on

siamese fighting f i s h CBatta - sp lendens) .

Eister (1967) repatted biochemical tissue changes

associated w i t h pesticide exposure in fish, He observed the

appearance of the 'Broken back syndrome', among f i s h . This

led Mehrie and Mayer (1975) t o biochemical research dealing

with vertebral development i n feathered minnows. The most

important biochemical change caused by insecticides has been

repotted to be the induction phenomenon (Stevens - e t - = D al

1972),

Biochemics~ changes following administration of

pesticides on oxidat ive enzymes and organic constituents in

different organisms have been studied by several workers

(Dreisbach, 1983; Tayyaba et &., 1981; Naiyara Yasmeen,

1989 1 .

Organophosphate induced changes i n protein metabolism

Pesticides are known to a l t e r prote in (Bergen G., 1 9 7 4 1 , l i p t d (dhatia - et -- a l 9 1972) and nucleic acid (Bergen

et a 1 - - - * 1 9 7 4 ) metabolism. Many pesticides, especially

organophosphorous and carbamates exer t their act ions by

inhibiting the cholinesterases. Organophosphorous

insecticides have an effect on protein metabolism in

addition t o their specifkc inhibitton of cholinesterase

enzymes (Clouet and Walsch, 1963) . Correlation between the

toxicity of pesticides w l t h protein metabolism, oxidative

processes and energy utitlzatlon as possible prtmary causes

of neurotoxic process has also been reported (Porcellati,

1969) .

Metasystox induced regional a l t e r a t i o n s were observed

i n the brain leve,Ls of DNA, RNA, DNase, RNase and prote ins

in male adult albino r a t s (Tayyaba st g., 1981 1 . S i g n i f i c a n t decrease in DNA concentration i n cerebrum and an

increase i n remaining par ts of r a t brain was demonstrated

(Tayyabr - e t a., 1981). The increased activity of DNase in

cerebellum, brain stem and s p i n a l cord and diminished

activity in cerebtum has been found during pesticides impact

(Tayyaba, - et G., 1981).

Investigations o f Ansari -- et a l . (1988) showed diazinon

caused considerable changes in nuclei~ acid and protein

metabolism in the brain of Zibra fish.

Inhibition in the synthesis of DNA, RNA and proteins by

organochlorine LnsectLcides were found in various biological

systems like mouse peritoneal macrophages, sea urchin

embryo, C r i t h r i d i a Easiculata, zebra f i s h Brachydanio rerio

(Saxena et el., 1981).

Increase in the content of t o t a l proteins and free

amino acid i n l i v e r o f T l t a p i a qossambica was reported on

malathion exposure (Kabecr Ahmed Sahib - e t a 1 1984). - I n

v i t r o studies using labelled amino acids also confirmed

increased protein synthesis specially more in liver than any

other tissue in T i l a p i a mossambica exposed to malathion

(Kabeer Ahwed, 1979). Increase i n the protein content i n the

Rana brain of methyl parathion exposed tadpoles of

cyanophi~ictia was reported by Naiyara Yasmeen, 1989.

I n h i b i t i o n of protein synthesis and some changes in

phosphoLipld metabolism were found i n the nervous tissue of

hens administered w i t h neurotoxic organophosphorous

compounds (Porcellati, 1971). Significant decrease in

protein synthesis hsa been reported by pesticides Ln Hells

cells, mouse peritoneal macrophages, sea urchin embryo,

crithidia fasiculata and tetrahymena pyrifornis (Saxena et - a 1 -* 1981) . Studies of Ramesh c+ fi. ( 1984 ) showed a

significant decrease in the rate of protein synthesis after

methyl parathion administration in pregnant r a t s . Sivaiah

and Ramana Rao (1978) reported a decrease in the prote in

content in s n a i l , - P i l a globosa on the exposure t o malathion.

Certain cases of orgrnophosphoroue poisoning leading to

complex changes in the molecular architecture of membrane

bound enzymes has been reported (Eto, 19741, Ntiforo and

Stein (1967) found alterations i n the permeability

mechanisms due t o in t erac t ion of malathion with the

structural components of the lysosome membrane. Poisoning

with TOCP resulted in inhibition of the activities of ~a*-K+

and M ~ ~ + ac t i va ted ATPases in chicken sp ina l cord (Brown and

Sharma, 1976). Inhibition in the a c t i v i t y Levels of ca2+ and

Ng2+ ac t iva ted ATPases was reported on parathion toxicity

(Price, 1976) . Christensen and Tucker, (1976) reported

severe inhibition in the ATPase and carbonic anhydrase

activities i n c a t fish Ictaurus punctatus during

organophosphate induced t o x i c i t y . Inhibition of ca2'-~~pasc

a c t i v i t y i n fish Tl1apLa was reported on several

organophosphate pesticides exposure (Anjum and Siddiqui,

1 9 9 0 ) . Decreased a c t i v i t y level of ATPase systems during

methyl parathion s t r e s s has also been reported in the

hepacopancreas and gills of fresh water mussel Lamelllden~

maralnalis (Mootthy et g., 1985).

Cbinlcal enzymes such as serum alanine and aspartate

transaminase, LDH, aldolase and phosphotases were found to

be af fected considerably during organophosphate poisoning

(Tucker and Leitzke, 1979) . Naishtein - e t - al. (1970)

determined the depression of hepatic and glycolytic enzymes

SDH, LDH, cytochrome oxidase on DDT poisoning in rats.

Mala th ion stimulated tyrossne transaminase and alkaline

phasphatase i n r a t liver has been reported (Murphy and

Por te r , 1966).

Alterations in the citric ac id cycle enzymes such as

isocitrate, succinate and malate dehydrogenase were reported

on methyl parathion toxicity in different tissues i n a

var i e ty of animals. This suggests an abnormality in

mitochondrial o x i d a t i v e metabolism (Moorthy - e t * a 1 9 1989)

Inhibition I n the activity Levels of B-glucoronidase and

manoanine oxidase was reported by parathion exposure

(Tearitore and Caruso, 1968). Roja KovLck and Marsh, (1976)

have shown t h a t chinornethfonate, an acaricide is a potent

inhibitor of caLcium dependent and calmodulin stimulated

ph~sphodiesterese enzyme. Hence levels of cycl ic AMP are

also affected by organophosphorous compaunds.

Organophosplwruus induced changes in Carbohydra~e metabolism

Carbohydrate metabolism was found to be considerably

af f acted by (Sakaguchi , 1972 1 . Considerable

information is available on the carbohydrate metabolism

during organophosphate t o x i c i t y . For i n s t a n c e , Sakaguchi

(1972) reported elevated levels of serum transaminases,

glucose, t r i g l y c e r i d e and t o t a l cholesterol levels, l ead ing

to impaired glycogen metabolism in muscle tissue in carp

exposed to malathion, trichlorfon or dichlorvos. Changes in

glucose metabolism have been demonstrated in the various

tissues of f re sh water mussel exposed to methyl parathion

(Moorthy, et G., 1985) .

Kaundinya and Rarna Murthi (1979) reported changes I n

blood glucose, muscle, liver glycogen content and

phosphorylase activity tn fish Satotherodon mossambica on

sumithion exposure. Sub acute poisoning with organophosphate

pesticides in rats resulted in inhibition of tissue SDH

activity (Bahtg , 1 9 7 5 ) .

Organophoaphorous compounds are known t o cause hyper

glycemia and increase i n Liver glycogen (Honne Gouda g . , 1984). Jyothi -- et 8 1 . (1989) reported decreased glycogen and

phospholipid content in selected tiosues of fresh water fish

Channa punctatus on mala th lon expd8ure. Deplet ion of t o t a l - carbohydrate* and glycogen content was reported i n the

s e l e c t e d tLssues of the Snail p i l a plobosa ( S i v a Prasad Rao,

e t g., 1983). N a t a r a j a n (1981a) found a decrease In the SDH - activity and t l s s u e respiration and an increase i n LDH

activity i n the gill, brain, liver, muscle and kidney

tissues of f i s h Channa striatus on exposure to sublethal

concentrat ion of metasystox.

Organophosphate induced changes i n 1Apid ietabolisr

Lipid metabolSsm was found to be considerably affected

by pesticides (Moorthy - et - 9 a 1 1985 ) . Considerable

information i s available on the l i p i d metabolism during

organophasphate poisoning. For instance, Veeresh and Swamy

(1984) reported a general inhibition in the biosynthesis of

l i p i d in non target tissues of animals on exposure to methyl

parathion. Antunes Madeira - e t - al. (1980) found that

parathion and azinophos caused induction of molecular

disorder in lipid bilaysrs.

PorceLlati (1971) found biochemical defects in

phosphol ipid metabolism in some nerve tissues of hens

administered with neurotoxic organophosphorous insecticides.

Mahdi Hassan and Naoeem Ahmed, (1985) found dose re la ted

alterations in the levels o f t o t a l l i p i d s , phospholipids,

and cholesterol in various regions of brain and spinal cord

in experimental animals on methyl parathion exposure.

Regional altarattons in the brain l i p i d contents of

adult albino rats on DDVP exposure was reported by Tayyaba

and Mahdi Hssaan (1980). Choudhari and Chskrrbarti (1984)

reported a slight increase in Liver t o t a l l i p i d content on

acephate administration i n r a t s .

Considerable changes i n the phospholipid patterns i n

the Suckling rabbi t bra in was reported on dichlorvos

administration (Malinska ot &., 1984). S i v a Prasad Rao and

Ramana Rao (1981) demonstrated considerable decrease i n

to tab l i p i d s and phospholipids and an increase in the free

f a t t y acids and total cholesterol in the red muscle, g i l l ,

l i v e r and brain of methyl parathion exposed fishes.

Organophosphate tnetasystox induced augmentation in lipase

activity and l i p i d peroxidation in the cerebral hemispheres

and diminatLon i n the levels of lipids i n discrete areas of

brain in rats (Islam &., 1983).

Organophosphate induced Cardiotoxicity

Cardiac t i s s u e was found t o be considerably affected by

pesticides (OIBrien, 19601, Conridetable information is also

a v a i l a b l e o n cardiac t o x i c i t y during exposure to

organophosphorous Lnsectlcides. For instance, animals

exposed t o acute tox ic dose of organophosphorous

insecticides, on necropsy reveiled that the v i scera l organs

and their blood vcssehs were engorged w i t h dark venous . 7

b~ood, peritoneal effusion, a dirtended right side of the

heart , collapsed and ischemic lungs, spasms in the small

intestine and hemorrhages of small vessels in some organs

(Ecobichan, 19821. Khanna -- et a1. (1978) reported that single

dermal applicatSon of fenitrothion administration in rats

caused significant decrease I n the size of organs like

kidney and heart with increase in the size of liver and

spleen. Haamatological s tud ies (Natarajan, 1981) revealed

that organophosphorous insecticide metasystox decreased the

concentratton of WBC, PCV and haemoglobin in fish Channa

striatus. Morgan -- e t a l . (1980) found damage of bone marrow

in animals exposed t o Insecticides. Decrease in RBC, PVC and

haemoglobin concentration was observed in sumithion treated

fish Tilapia rossambica (Madhu, 1983). Panday -- et al. (1976)

reported a similar decrease i n RBC and haemoglobin content

i n Channa punctatus a f t er treatment with malathion. Mandal

and Kulshrestra (19801 also observed a loss of RBC i n

Clarius battachus on treatment with lppm of sumithion.

Differential responses in the rate of heart beat of

LameLLZdans m a r ~ l n a L i s was reported during malathion and

methyl parathion t a x f c i t y (Ramana Rao et a l . 1983). - - AkiIender Naidu e t a l . (1987) found an inhibition in the -- heart r a t e , cardiac a r r e s t and inhibition of AChE in

Dichlorvas [DDVP) treated r a t s . This cardiotoxic effect of

DWP7't@ar sua#elf ad; ga iw - laadie~ed by thm -accuaulsead aCh and

A C ~ E inhkbitiol (AkWlOndor Nlldu &., 1987). During the

study on carbophenothion poi~oning i n canada geese Branto

canadensis, ruptuved a o t t a and i n t e s t t n a l haeaorthages were

found. There ruggtsttd the possFbLLLty o f massive increase

in blood pressure as a major cause of death during

organophosphorous insecticide induced toxicity (Jennings - e t

a l -* 9 1975 ) . Investigations of Robineau and Guitton 11987)

revealed cardiotoxic effects of methyl phosphorothionate

[EIPT). MPT inducted cardiac arrhythmias leading t o death,

Increase i n the a r t e r i a l blood pressure ( 6 0 mm Hg) was

reported during soman induced c a r d i o toxicity in rats

(Magrie - e t at., 1988).

During a study on cardiac toxicity i n pest ic ide

formulators, Saiyed -- e t a l . (1984) found abnormal heart rates

(Bradycardia and Trachycardia) and abnormalities in rhythm

conduction, a t a l l R wave and a ventricular bigeainy or

trigeonimy. Trachycardia with an increase in blood pressure

and pulse r a t e was found alongwith muscular fasciculation

(Ecobichon, 1 9 6 2 ) .

Organophosphorous induced hepatotoxicity

Gross pathological and hiatopathological effects often

accompany Insecticide exposure (Tucker and Leftzke, 1979).

Insecticide induced hepatopathy has been reported i n fishes

and ocher animal8 (Mandal and Kulashrestra, 1980; Atnnt Kutty

and Rage, 1 9 7 7 ) . Prominent among insecticides with

m~crosomal enzyme inducing a b i l i t y are the f a t soluble

chlorinated hydrocarbon insecticides IGrossi, 1974) . A

detailed review of histopathological effects of pesticides

and related chemicals on the liver of fishes is available

(Couch, 1975) .

Considerabl-e infornation is a v a i l a b l e on

organophosphorous induced hepatotoxicity in f lshes.

Koundinya and Rarna Hurthi 11981) reported reduction in the

rate of r e s p i r a t i o n of liver i n fishes exposed t o sunithion

and sevin. A significant inhibition of AChE and accunulation

o f ACh i n the liver of sunithion treated fish has also been

reported (Koundinya and K a ~ a Murthi, 1978) .

I n the liver of fish teleost Anabas fossilis,

inhibition of cholinesterase by dimethoate and its

subsequent recovery a f t e r three weeks was reported by A w a s t i

and DubaLe ( 1 9 8 3 ) . Khanna et a l . (1978 ) found that a s ing le -- dermal a p p l . i c a t i o n of fenitrothion insecticide caused

significant increase in the s i z e of l i v e r in rats,

Fenitrothion also caused changes in hepatic and renal non

specif ic carboxyl esterases along with erythrocytic and

bra in AChE i n male Wistar r a t s (Ecobichon, at c., 1980).

R a t r fed with low pro te in diets and exposed to

malathion ahowrd a eagnificant Lncrease in the a c t i v a t i o n of

GOT and alkaline phosphotasr in liver (Vaishwanar and Malik,

1984 ) . Bieter (1970) reported cellular necrosis and f a t t y

tissue changes in l i v e r and other tissues and suggested that

these a r e associated with leakage of tissue enzymes i n t o the

blood. Kabeer Ahmed (1979) reported increased & - v i t ro

protein synthesis in the liver o f malathion exposed fish

Tilapia mossambica.

Acute histopatho~aglcal effects of malathion on the

liver of r a t was reported t o be due t o the damage occurring

in the liver tissue due t o histolysis, nuclear enlargement,

pycrosis, vacuolation and necrosis (Konno - et -- a 1 I 1 9 8 4 ) .

Similar changes were found in f r e s h water a i r breathing

teleosti Anabas testudineus exposed t o df f f erent

concentrations of cythion (Arun Kumar Ray and Bhattacharya,

1984)

Decrease i n the Levels of SDH and LDH activities,

carbohydrate and glycogen contents were reported in the

Liver of methyl parathion exposed f i s h Tilapia aossambica

(S iva Prasad Rao and Ramana Rao, 1979) . Considerable

increase i n the total l i p i d s and slight decrease I n

phaspholipidr and trigLycerider are reported in the liver of

acephate expored r a t s (Choudhari and Chakrabarti, 1984).

Siva Prasad Rao and Ramana Rao- (19811 demonstrated

considerable decrease in the total l i p i d s and phospholipida

along with elevation in the l e v e l of f a t t y acid and t o t a l

in the l i v e r of methyl parathion exposed fishes.

Teratoganic effects

With Increasing use of organophosphorous compounds as

insecticides I n the U.S. and West European Countries, their

teratogenic effects on the other non-target organisms in the

ecosystem are becoming increasingly important (Gill and

Latram, 1972 ) . Organophosphate induced teratogenic effects

leading to cent ra l nervous system lesions (Baron and

Johnson, 1964) and skeletal abnormalities have been reported

i n various species of btrds .

Teratogenic signs include lack of feathers, parrot

beak, shortening and deformation of the legs and spine, wry

neck, edema and more rarely syndactylia and visceral hernia

( E t o , 1 9 7 4 ) . Studies of Wilson -- et al. (19732 revealed the

inhibitory e f fec t of malathion, malaaxon, parathion and

paraoxon on the growth of cultured chick embryo pectoral

muscle c e l l s . Studies with O,lmg/egg concentration of

parathion revealed the teratogenic effects of parathion on

developing chick embryos (Marliac, 1 9 6 4 ) .

Malathion administration to Leghorn chick embryos

ahowed teratogenic signs (Greenberg and Lattam, 1969).

25

Injections of parathion during embryonic development

affected the formstion of cartilagenous and osseous

s k e l e t o n , eye c a t a r a c t s , a s c i t e s , and hepatic degeneration

in both ducks and chicks (Khera, 1966).

Fetal malformations, resorptions or decreased fetal and

placental weights were found during intraperitonial

treatment of maternal r a t s with different organophosphorous

compounds (Eto, 1974). Reduction in f e t a l GhE a c t i v l t y

following intraperitonial i n j e c t i o n of methyl parathion and

parathion into pregnant rats, clearly indicated

transplacent a 1 passage of these lipid soluble

phosphorathionates [Ackermann and Engst, 1970). Chronic

poisoning with disulfoton at a dosage level of 1Oppm in the

diet reduced the number of pregnancies of rats (E to , 1974).

Breeding experiments with Wistar r a t s with 24Uppm malathion

showed a decrease in litter s i z e weight and an increase in

the incidence of ring t a i l s (Baron and Johnson, 1964).

Observations following acctdenta/suicfde attempts ( w i t h

malathion, methyl parathion) in human beings by Czeieel e t - aX. - (1973) indicateci chromosomal breaks in acutely

intoxicated patients. These were temporary but potent t o

have long t e r a consequences.

Organophosphate fnducd delayed neuropathy and neurotoxlclty

For most inrectlcidea currently i n use, it has c l e a r l y

been establi~hed that the nervous system is the target sLte.

However, tho mechanism of act ion on the nerve i s

considerably different among these insecticides acting on

the nerve. Ckolinesterasas Ln the nervous system are the

prime target for certain inoecticider such a s

organophosphates and carbarnates (Eto, 1 9 7 4 ) . Whereas no

specific enzyme system has bean clearly established as the

target fot other insecticides.

The orgefiophosphorous i nsec t i c ides due to their

instability Leave no residues and hence pose l e s s e r problem

than the chlor inated hydrocarbon insecticides (Hissaki

Tsumuki em, 1970). Thus no accumulation af

organophoaphorous i n s e c t i c i d e s I n the tissues have been

observed, but many have a high acute toxicity to mammals

(WiSkinson, 1976) .

Certain of the anticholinesterase organophosphorous

compounds cause chronic, irreversible, demyelinating Lesions

in the nervous system, as well as s k e l e t a l abnormalities in

mammals and in var ious species of birds (Fishbein, 1976).

The insecticidal activity and mammalian t o x i c t t y are

generally accepted as due t o the phosphorylation of AChE

( € t o , 1 9 7 4 ) . Besides AChE, organophosphates also i n h i b i t

cholinesterase, aLiesterasas, and so called ser ine

'protelneses' by phosphorylating hydroxyl group in the

active zone of the enzyme molecule (Johnson, 1982). The

inhibition of these enzymes i s known t o disturb the normal

nerv&u& funct ion, C P U S ~ ~ ~ severe and lethal damage the

organism, f i n a l l y resulting i n its death. A likely

consequence of AChE inhibition is the accumulation of acety l

cho l ine . Smallman and Fischer (1958) reported 260% rise in

the level of a c e t y l choline in organophosphorous treated

insects.

Many organophosph~rous compounds show a chronic

neurotoxicity which is not due to AChE inhibition, but

another unknown mechanism is suggested t o be involved. This

is accompanged by irreversible demyelination both i n the

central and peripheral nervous system o f some species of

vertebrates (Ohkawa, 1982). Johnson (19751 hypothesized

that organophosphorous compounds-induced delayed

neurotoxicity I s attributable to a large degree of

inhibition of an enzyme characterized as neurotoxic esterase

(NTE). Lotti and Johnson (1978) suggested that the degree of

inhibition of NTE and AChE i n hen's bra in provide a guide t o

show delayed neurotoxicity of organophosphorous e s t e r s .

The delayed neurotoxicity produced by some compounds

has been defined more c l e a r l y and consistently than the

behavioural effects of organophosphates (Abou Donla, 19811.

The rigns of organophosphorous induced delayed neurotoxic i ty

include polynauritis characterized by a f lacc id para lys i s of

the d i r t a l skt~letel mu8cle o f the extremities, a s s o c i ~ t ~ d

with degeneration o f the myelin and axons of peripheral

nerves, eipLnal cord and medulla (Ecobichon, 1982).

The earliest report of organophosphorous induced

delayed neurotoxicity involved accidental exposure to t r i -

ortho-cresyl phosphate (TOCP) contamination in bootleg

liquor and adulterated cooking oils (Ecobichon, 1982) . The

syndrome that developed following TQCP poisoning has been

reported in detail in the literature (Morgan and Penovich,

1978, Ecobichen, 1982) . The clinical picture, which develops

from 5 to 21 days a f t e r ingestion of TOCP consists of

rapidly developing, f l a c c l d , bilateral paralysis of the

d i s t a l muscLes of the arms and legs (Ecobichon, 1982).

Pathological observations include wallerian degeneration of

centrat and peripheral myelinated axons and Irreversible

spinal cord lesions (Abou Donia - e t * a 1 9 1983).

There is considerable evidence from both animal and

human case studies that some organophosphates can produce a

delayed neuropathological syndrome stmllar to that produced

by the tris-ortho-creryl-phosphate esters. These compounds

(including mipafox, parathion, malathion, fenitrothion,

leptophos and trichlorfon) evoke a syndrome of delayed

neurotoxic affects several week8 fo l lowing an episode of

acute in tox i ca t ion (Ecobichon, G., 1977; Hier8ons and

Johnson, 1975). Many animal species including man, dogs,

cows, sheeps, r a t s , hens and pheaeents are more or less

unsusceptible to be attacked with an a t a x i a . Cats and hens

(young chicks are insensitive before a c r i t i c a l age of 55 t o

70 days) a r e most sensitfve to organophosphate poisoning *

(&to, 1 9 7 4 ) .

Studies of structure-activity relationships have

revealed the core structural features t h a t are likely to

cause delayed neuropathy (Caroldi - et -. a l 9 19841, but the

biochemical mechanisms are s t 1 1 1 under active investigation

(Johnson, 1982). No neurochemlcal changes i n t h e brain

following exposure t o neurotoxic organophosphates have been

reported. Freed - e t _.._ a l . (1976) suggested a possible

involvement of strlatat-dopamine In the delayed neurotoxic

effects of some organophosphates. Rats fed mipafox daily for

35 days exhibited a t a x i a and decreased level of dopamine i n

the striaturn (Sourkers, 1981). Reichert and Abou-Donia

(1980) reported that the inhibition of f a s t axoplasmic

transport may be a mode of action for neurotoxic

organophosphates.

S e i f e r t and Caslda (1984) found the rote of

microtubules and asaocLated proteasea in the biochemical

pathways arrociated with the production of organophosphorws

induced delayed neuropathy. Endopenous proceases that

degrade microtubule-a88ociated proteins were strongly

inhibited by neurotoxic organophosphates insensitive

speclee, suggesting t h a t these enzymes may be targets for

organophosphorous Induced delayed neuropathy (Seifert and

Casida, 1984)-

Neonatal Status and Pesticide PalLution

Number of out breaks of neonate accidental poisoning by

pesticides have been reported. Main sources for accidental

poisoning by pest ic ides is the contamination of stored food

in pesticide used conta iners and use of pesticide treated

grains as food. Repeated surveys have shown that Indians are

daily eating food laced with some of the highest amounts of

t o x i c pesticide residues found I n the world (Rajchengappa

and Chidanand Rajghatta, 1989). Studies indicate t h a t right

from the day our babies begin to suckle, they are taking in

pesticide depostted breast milk. And some readymade baby

foods too are similarly contaatnated (Rajchengappa and

Chidanand Rajghatta, 19891.

S t a t i s t i c a l surveys of pesticide exposure mortality and

morbidity reported that neonates are the victims of a high

percentage of f a t a l poisoning. According t o a report of

American environmental group natlonal resources defense

Council. (NRDC) tha t preschoolers a r e more susceptible t o

pesticide residues. Wilh.1~1 (1983) reported that development

of neonate and its approach with the envi~onment during the

early periods of l i f e purely depends an the state of the

environment tn which the neonate thrives for substances of

Life.

The patterns of neonatal deaths revea l the difference

in the balance of forces at work behind the scenes in two

entirely different types of worlds. In the Industrialized

world, the dominant force is the economic and social

progress, where s c i e n t i f i c research plays a supporting role.

In most of the developing countries t h i s pattern is being

intervened by f a c t o r s like harmful pesticides (WHO Report,

1984). The high r a t e of m o r t a l i t y among neonate i s of dire

importance. The p i l i n g evidence of pollution effects on the

neonates should be taken a s a c l e a r warning. Neonatal

mortal i ty r a t e is regarded as one of the most important

index of development of a society and t h i s depends directly

on environmental s a n i t a t i o n (Singha1 et al 1986). - * 9

Most of the toxicological studies on the effect of

pollutants, given either prenataly or postnataly reveal

damage to the developing cent ra l nervous system ( I y e t et - sD, 1968). In addi t ion to acting d i r e c t l y on the developing

neurons, pesttcides also a l t e r the developing CNS directly

through the maternal blood stream (Joffe, 1969). Several

reports have appeared in the literature on the effects of

p o l l u t a n t s on ATPasea (Uaodinma - e t - 0 9 a 1 1984) glutamine

ryntheta~8 (8011 BerL, 19661, reproduction, foetal brain

abnormalities (Ansar i , 19851, haemodynsnics (Hindaka - e t -. a1 9

19861, changee i n the levcls of purine and pyramidine

nucleotides (Hisanaga et G., 19861, development of neonatal

bra in (Reuhtl and Chang, 1978) and biogenic arnines (Taylor

e t a 1 1973) . - '

Thus any disturbance to the neonates can be expected to

affect the CNS. The indiscriminate use of harmful pesticides

provide a base for significant studies in this direct ion on

deve lop ing CNS. Therefore L t i s necessary t o save neonates

from the hazards of Life.

Statement of the Present investfgation

Pesticides are presently used I n increasing amounts in

the f i e l d s , preservation and control of vectors causing

dtsease to mankind and llvertock. Pesticides a r e generally

responsible for a number of biochemical and physiological

disturbances . The toxicity of methyl .parathion to sammats is

considerably lower compared to parathion. Methyl parathion

penetrates through the s k i n with greater difficulty than

parathion. Methyl parathion has been chosen for the present

study as It is widely uaed by farmers I n India to spray

paddy field. under the trade name 'Metacid 0 ~ r u e t o ~ a

reports have i nd ica ted the presanc@ of i e thyl parathion i n

water (Eichelberger and Lichtenberg, 1971 1 , s o i l

(~buchowska, 1967) and non aquat ic plants (Slngh and Singh,

1978) . Eichelberger and Ltehtenberg, (1971) observed that

methyl parathion pers is ted I n water , soi l and carp for about

a period of 2-3 weeks, after a slngle expoeure. Hence the

human population is undoubtedly exposed to t o x i c i t y caused

by organophosphorous pesticide due to its wtde spread use

and environmental persistance.

Thus despite constderable research in the field of

pesticide t o x t c i t y , Information available is very scant on

the developing vertebrate nervous system. Information is

totally lacking on the neurotoxic effects of insecticides

durtng critical stage of central nervous system development.

Keeping this in view the present investigation was proposed

to elucidate the t o x i c impact of methyl parathion on the

developing central nervous system, It is hoped t h a t t h i s

study will elucidate the dysfunction of the developing

centra l nervous system during methyl parathion exposure.

The ra t is used an experimental animal model. I n this

mammalian model the brain undergoes significant maturation

(maturation of neuronal processer i n the cortex) during the f i r a t pocltnatal month, when i t is amenable t o rystematlc,

functional and chemical investigation. Developing r a t pups,

2nd and 7th day postnatal have been used for the study. he

a l te ra t ion8 occurring i n certain neuronal indices such as

brain specific ac id ic proteins viz., calmodulin and S-100

prote in , neurotransmitters and enzymes associated with

neuronal a c t i o n have been analysed i n different regions of

the cen t ra l nervous system viz., cortex, brain stem and

s p i n a l cord. Ana lys is has been directed to investigate the

changer occurring in the tota l RNA, total proteins, ATPases

and dehydrogenases in the central nervous system of a

developing mammal during methyl parathion induced toxicity.

It i s hoped t h a t this study will elucidate disrupt ions

of the speci f ic molecular mechanisms in the developing

central nervous system on pesticide exposure and will be of

h e l p i n the analysis of mental debilities I n children, The

knowledge may be of immense use i n averting brain

dysfunction due to organophosphorous induced toxicosis.