Hyperphagia without obesity in septal-lesioned cocks

Download Hyperphagia without obesity in septal-lesioned cocks

Post on 14-Nov-2016

216 views

Category:

Documents

3 download

TRANSCRIPT

  • Physiology & Behamor, Vol 20, pp 1 -6 . Pergamon Press and Brain Research Publ , 1978. Pnnted m the U.S A

    Hyperphagia Without Obesity in Septal-Lesioned Cocks

    B. ROBINZON, N SNAPIR AND PEREK

    Department of Ammal Science, Faculty of Agriculture, Hebrew Umverszty of Jerusalem, Rehovot, Israel

    (Received 8 Apnl 1977)

    ROBINZON, B, N. SNAPIR AND M PEREK Hyperphagta without obesity m septal-leszoned cocks PHYSIOL BEHAV 20(1) 1-6, 1978 - Placement of electrolytic lesions m the septal area (S A ) m chickens caused a marked increase m food retake which was not accompanied by development of obeuty. Oxygen consumpUon of the S A lesioned birds was s~gnifieantly higher than that of the controls Alemnophyhc-thyrotrople cell population of the adenohypophym and percentage of acUve follicles m the thyroid gland were higher for the S.A lesioned birds than for those of the control birds The S A lesions caused also an increase m the somatotroplc actmty The posslbthty that the previously found suppression effect of the olfactory bulbs on the thyrotroplc and somatotropic actavmes m the intact chicken is medmted vm the S A, ts discussed

    Septal area Hyperphagm Thyrotroplc aeUvlty Somatotroplc acUvlty

    PLACEMENT of bdateral septal lesions m geese by intra- cranml injections of 6-hydroxydopamme (6-OHDA) eh- cited a marked increase m food retake, which lasted for at least 60 days post operation, after which the experiment was terminated [22] In contrast to hyperphagla caused by basomedlal hypothalamus (BMH) lesions, no obesity devel- oped m the septal-lesIoned geese Sinular results were obtained with rats [17, 18, 19] The results with the geese are parallel to those reported on the chicken, m wluch removal of the olfactory bulbs (O B ) caused a marked increase m food Intake but without obesity [ 15] In this case it was proved that the surgical removal of the O.B ehclts a pnmary increase m thyroid activity followed by a compensatory increase In food retake [ 15 ]

    The purpose of the present investigatlon was to examine whether septal lesions in the chicken also lead to hyper- phagm unassocmted with obesity and if so, to record the accompanying physlologlcal phenomena

    METHOD

    A mmals

    Twenty White Leghorn cocks, 2 months old, were kept in mdmdual cages, fed a commercml breeder mash ad hb and subjected to 14 hr hght daily

    Surgical and Experimental Procedure

    Ten days after the begmmng of the experiment, the birds were dmded into two equal groups Anodal, DC bilateral electrolyhc lesions were placed in the septal area (S A ) of one group of birds using stainless steel electrodes passing 2 mA for 25 see The routine method for placing electrolytic lesions, using an x-ray atlas of the chicken brain [9,21 ] was apphed m thts experiment

    The foUowmg coordinates were chosen for reaching the SA AP=83mm, H=80mm, latera l=l 0mm

    Histological verification at the termination of the expen- ment revealed that In two birds the lesions were not located m the expected site and their data were omitted from the results

    The other group of birds were sham-operated and served as controls The experiment lasted for 280 days during which the following parameters were measured individual daffy food intake, and body weight, metatarsal length [20] and comb size [ 12] at 10-day intervals The obesity index was calculated based on the Lee Index [2,8] usmg the metatarsal length as representative of the body length as follows

    /nw 1000

    Metatarsal length

    The birds were penodlcally ejaculated for obtaining semen [4] Semen volume, sperm concentration [23] and motility [14], oxygen consumption at rest (RMR) and rectal temperature were measured penodlcally [ 15,16 ]

    Autopsy Procedure

    Prior to kalhng the birds, hepanmzed blood samples were drawn from the brachtal veto for deterrnmatlon of hemato- cnt and total plasma liplds [24] The birds were kalled by decapitation The brains of the lesioned birds were removed and fixed in 10% neutral Formahn The following were immedmtely removed, cleaned from adhenng tissues and weighed comb, abdominal adipose tissue, liver, testes, adrenals, thyroids and adenohypophysIs The liver, abdo- minal adipose tissue and a sample of the breast muscle were subjected to lipid extraction [ 10] and hpld percentage was determined using a gravimetric method

    Hzstologtcai Procedure

    Frozen frontal senal brain sections of 25 ~m thickness

  • 2 ROBINZON, SNAPIR AND PEREK

    were stained with thlonme The sectxons were subjected to mxcroscoplcal observation for locahzatlon of the lesion s~tes A representative sample from the center of the testes as well as the whole adenohypophysls, thyroid and adrenal glands were successively fixed in Boum-Hollande for 24 hr, carefully washed using &stalled water, and transferred to fresh 70% ETOH which was changed repeatedly The tlssues were routinely dehydrated and embedded m Tlssuemat Serial sections of 4 um thickness were tamed out Alternate sections of the adenohypophysls were alterna- twely stained with Alcxan Blue-PAS-Orange G [1,7] or with Wool green-Orange-G [13] The thyrmd, adrenal and testes sections were stained with Hematoxyhn-Eosln

    Statistical evaluation of the data was camed out using t-tests, and calculation of coefficients of correlation [3] The standard error tor each experimental group was calculated for the entire experimental period based on the following formula ~_~__E~ 2

    n

    RFSULTS

    Figure 1 shows schematlcal drawings of frontal brain sectmns [9] demonstrating representatively the location of the septal lemons As seen from Fig 2, a marked hyperpha- gla developed m the S A lesmned (S A L ) birds, as compared to the controls, and tins lasted until the end of the experimental period However, no differences were found m body weight between the two groups (Fig 3) Towards the end ot the experimental period the calculated obesity index ot the S A L cocks was lower than that of the controls, although the difference was not statlmcally slgmflcant (Fig 4) The coefficient of correlatmn between the dally food retake and the obesity index was positive for the control birds (r = 798, p

  • HYPERPHAGIA IN SEPTAL LESIONED COCKS 3

    2e

    ~ m 2~- -

    _D 1~- - ; "o 0 t41 ~- cont SE=012 =:

    SAL , SE=012 1 o 5oi do ,5ol

    Exper,mental per,od (days)

    FIG 3 Periodical changes m body weight of the control and S A L groups of birds Arrow indicates placement of lesion

    ilOO A - ~" SAL , SE:18

    Exper,mental per,od {days)

    FIG 5 Periodical changes m metatarsal length for the control and S A L groups of birds Arrow indicates placement of lesion

    i c >t

    e~ o

    @----O ont SE--28

    : ~SAL SB=34

    3(

    a

    E 0 u

    lg

    / /~ .- -~$AI.. 8E=15

    , Experlm~mtml per iod Cdaya)

    ! Exper,mental per,od {days) FIG 6 Penodncal changes m comb factor for the control and S A L groups of birds Arrow indicates placement of lesion

    FIG 4 Periodical changes m the obesnty index for the control and S A L groups of bnrds Arrow mdncates placement of lesion

    TABLE 1

    ADIPOSITY AND LINEAR GROWTH CRITERIA AT AUTOPSY TIME FOR THE CONTROL AND S A L GROUPS OF BIRDS

    Treatment Plasma Muscle

    Body total total Abdormnal achpose Ussue Lwer Metatarsal Obesity weqght hpnds hpnds Wew, ht Total hplds Weight Total hp]ds length index

    (g) (rag/100 ml) (%) (g) (%) (g) (%) (ram)

    Control 2240+111" 1612_+143 36+08 87+62 570_+ 82 336+24 60+03 1203+20 1086+18 n = lO (a)t (a) (a) (a) (a) (a) (a) (b) (a)

    SAL 2450-+115 1588-+1128 30-+02 205-+95 265-+142 360_+08 55-+02 1280-+1 1 1051_+23 n = 8 (a) (a) (a) (a) (a) (a) (a) (a) (a)

    *Mean _+ S E tF~ures which are not marked by the same letter are staUsUcally different from each other (/7

  • 4 ROBINZON, SNAP IR AND PEREK

    TABLE 2

    ADENOHYPOPHYSIS WEIGHT AND SELECTED CRITERIA FOR REPRODUCTIVE TRAITS FOR THE CONTROL AND S A L GROUPS OF BIRDS

    Treatment Adenc~ Semmtferous Total sperm

    hypophysls Testes Comb tubules Semen Spermatocnt per Spermatozoa weight wetght we~lht Hematocnt dmmeter volume ejaculaUon mottlity (rag) (g) (g) (%) O~m) (ml) (%) (I0 s) (0-7 degrees)

    Control 167+26" 302-+27 736-+37 413-+13 178-+18 071-+008 124-+42 3382-+154 62-+!2 n = I0 (a)? (a) (b) (a) (a) (a) (a) (a) (a)

    SAL 182-+28 3293-+282 987-+08 405-+12 169_+22 060-+009 123-+32 2788-+ 87 6 3 -*- 0 8 n = 8 (a) (a) (a) (a) (a) (a) (a) (b) (a)

    *Mean _+ S E tFtgures whtch are not marked by the same letter are statmUcally dtfferent from each other (p

  • HYPERPHAGIA IN SEPTAL LESIONED COCKS 5

    FIG 8 Photomicrographs of representaUve hlstologlcal sections of adenohypophysts of the control (a) and the S.A L (b) birds Alclan Blue-PAS-Orange G (x I100) Note the marked increase m alclano-

    phyhc-thyrotroplc cell populaUon m the S A L bird (arrows)

    tlon coefficient obtained between the daily food retake and the obesity Index m the S A L birds shows that the hyperphagla Induced by the S A destruction is secondary to the Increased energy expenditure, and possibly develops to prevent a decrease in adiposity below its normal set point The lower obesity index calculated for the lesioned birds - compared to that for the controls - may support this assumption

    Destruction of the S A In the rat ehclted similar results to those obtained with the chicken in respect to develop- ment of hyperphagla winch Is unaccompanied by an increase in body wetght [5, 17, 18, 19] In those Investlgatlons, however, no metabolic determinations were camed out

    It seems that the S A destruction in the cincken caused an increase m somatotrop~c ares acUwty as reflected m a longer metatarsus and a marked increase in alclonophyhc- somatotroplc cell population m the adenohypophysls It may be that the increase In comb slze in the S A L birds resulted from the synerglstlc elevation of both thyrotroplc and somatotroplc activities

    The syndrome caused by the S A lesions Is very similar to that caused by the removal of the O B In cocks [ 15,16 ] Removal of the O B in the chicken resulted m degeneration of axons winch pass along the medial forebrain bundles

    FIG 9 Photomtcrographs of representatave hlstologtcal sections of adenohypophysls of the control (a) and the S A L (b) birds Wool Green-Orange G (x 1100) Note the marked increase m acldophyhc-

    somatotroplc ceil population m the S A L bird (arrows)

    (MFB), cross the S A and reach the basomedlal hypothala- mus regton (authors' unpublished data) Tins may indicate that m the intact cock the suppressive effect of the O B on the thyrotroplc and somatotroplc activities is mediated via the MFB and operated through the hypothalamlc level Since destruction of the S A undoubtedly cause a discon- nection of the MFB, it may be suggested that the syndrome caused by the S A lesions is a direct result of a dlsconnec- Uon between the O B and the BMH

    It has been reported, however, that placement of lesions in the septomesencephahc tracts in the chicken cause anse m the TSH content in the rostral lobe of the adenohypo- physls [6] and an increase in the I TM uptake and release rate from the thyroid gland [ 1 1 ] As the septomesenceph- ahc tracts pass through the S A , one can assume that damaging them by leslonmg the S A , could also be the cause or an additional cause of the increased thyrotroplc activity found in the present experiment Further investiga- tions in this direction are needed

    ACKNOWLEDGEMENT

    The authors acknowledge with thanks the generous contnbutlon of Mr Joseph Taylor of London, England, which enabled them to carry out this work

    REFER ENCES

    Adams, C W M and K V Swettenham The histological 2 Bernardts, L L and F R Skelton Growth and obesity m male ldentlficaUon of two types of basophfl cell m normal human rats after placement of ventromedml hypothalamlc lesions at adenohypophysts J Pathol Bact 75.95-103, 1958 four different ages J Endocr 38: 351-352, 1967

  • 6 ROBINZON, SNAPIR AND PEREK

    3 Brownlee, K A StaUstlcal theory and methodology m science and engineering (2nd ed ) New York John Wiley, 1965

    4 Burrows, W H and J P Qumn Artificial insemination of chickens and turkeys Orc US Dept Agnc 525-529, 1939

    5 Donovlck, P J , R G Burnght and P L Glttleson Body welght and food and water consumption m septal lesioned and operated control rats Psychol Rep 25 303-310, 1969

    6 Egge, A S, W J Radke and R B Chmsson The effect of hypothalamlc lesions on thyroid-stimulating hormone concen- trahon m the chicken pltmtary Poultry Scl 54: 1628-1630, 1975

    7 E1 Etreby, M F , K D Richter and P Gunzel Histological and htstochemlcal dffferentmtlon of the glandular cells of the anterior pltmtary gland m various experimental animals Excerpta Med (Amst ) Int Cong Ser 288. 270-281, 1973

    8 Feldman, S, N Confortl and I Chowers Complete inhibition of adrenocort~cal responses followmg scmtlc nerve stimulation m rats with hypothalamlc islands Acta Endocr 78 539-544, 1975

    9 Feldman, S E , N Snaplr, F Yasuda, F Treutmg and S Lepkovsky Physiological and nutnttonal consequences of brain lesions A funclaonal atlas of the chicken hypothalamus Hdgardm 41 605-623, 1973

    10 Folch, J , N Lees and G H Sloan-Stanly A stmple method for the isolation and purification of total hp~ds from antmal txssues J B~ol Chem 226 479-509, 1957

    11 Gehrmann, W H The effect of hypothalam~c les~ons m the White Leghorn cockerels Ph D d~ssertatmn, The Umvers~ty of Arizona 1967

    12 Lowry, M M Compensatory testlcular adjustments following the mjectlons of small quantities of androgen into unilateral castrated White Leghorn cockerels Poultry Sct 37 1129-1130, 1958

    13 Nesselrooy, J H J Van and J M Berkvens A stare for somatotrop~c cells m the rat p~tu~tary gland Z Versuchstterk 15 94-95, 1973

    14 Plstenma, D A , N Snaptr and H C Mel B~ophyslcal characterization of fowl spermatozoa 1 Preservation of motthty and fertthzmg capacity under conditions of low temperature and low sperm concentration J Reprod Fert 24 153-160, 1971

    15 Robmzon, B, N Snaplr and M Perek Removal of olfactory bulbs m chickens consequent changes m food retake and thyroid acttvtty Brain Res Bull (In Press), 1977

    16 Robmzon, B, N Snaplr and M Perek The interrelationship between the olfactory bulbs and the basomedud hypothalamus m controlhng food retake, obesity and endocnne funchons m the chicken Bram Res Bull (In Press), 1977

    17 Smgh, D Preference for mode of obtaining reinforcement m rats with lesions m septal or ventromedlal hypothalamlc areas J comp phystol Psychol 80" 259-264, 1972

    18 Smgh, D Comparison of behavioral deficits caused by lesions m septal and ventromedlal hypothalamlc areas of female rats J comp phystol Psychol 84" 370-379, 1973

    19 Smgh, D and D Meyer Eating and dnnkmg by rats with lesions of the septum and the ventromedlal hypothalamus J comp phystol Psychol 64 163-166, 1968

    20 Snaplr, N, I Nlr, F Furuta and S Lepkovsky Effect of administered testosterone proplonate on cocks functionally castrated by hypothalamlc lesions Endocnnology 84 611-618, 1969

    21 Snaplr, N, I M Sharon, F Furuta, S Lepkovsky, H Ravona and B Robmzon An x-ray atlas of the saglttal plane of the chicken dlencephalon and its use m the p...

Recommended

View more >