cho storage diseases powerpoint

Carbohydrates Storage Carbohydrates Storage DiseasesDiseases

By

Dr Khaled Saleh Al gariri

2014

What is glucose used for?• Immediate carbohydrate energy &/or

glycogen storage (Liver & Muscle)

• Brain, central nervous system (CNS), & red blood cell (RBC) function

• Requires a minimum of 100-150g carbohydrate day (continuous)

• Muscle functioning (muscle glycogen)

• Fat synthesis (excess energy intake)

Glycogen• The storage form of glucose

• Made from dietary carbohydrate sources

• All carbohydrates are converted to glucose then 1) used immediately or 2) stored as glycogen

Glycogen Storage

• The Liver (100 grams; 400 Calories)• Is used for blood sugar (glucose)

regulation

• The Muscle (1-4 grams/100 grams of muscle)

• The level increases with high carbohydrate

diets & exercise

• Is used for the working muscle

Blood Sugar (glucose) Regulation

• Regulation of the blood glucose level depends on Regulation of the blood glucose level depends on liver:liver:

• 1. extracting glucose1. extracting glucose from blood from blood

• 2. synthesizing glycogen2. synthesizing glycogen

• 3. performing glycogenolysis3. performing glycogenolysis

• 4. performing gluconeogenesis4. performing gluconeogenesis

By hormones that are produced in the pancreas• The hormones effect the liver & muscle cells

– Insulin: decreases blood sugar levels

– Glucagon: increases blood sugar level

Blood Sugar (glucose) RegulationInsulin

Blood Sugar (glucose) RegulationGlucagon

1.1. Disaccharidase deficiency syndromeDisaccharidase deficiency syndrome

saccharasesaccharase = = enzyme which hydrolyenzyme which hydrolysesses disaccharide disaccharide saccharosesaccharose (to fructose and glucose(to fructose and glucose))

lactase lactase = = enzyme which splits disaccharide lactose enzyme which splits disaccharide lactose

((to to glucoseglucose and and galactose) galactose)

maltase maltase = = enzyme which splits disaccharide maltoseenzyme which splits disaccharide maltose

(to two molecule of glucose)(to two molecule of glucose)

MechanismMechanismss a)a) Activity of disaccharidase is decreasedActivity of disaccharidase is decreased decreaseddecreased

hydrolysishydrolysis o of disaccharidef disaccharide decreased reobsorption of decreased reobsorption of

substratesubstrate increased concentration of disaccharide in increased concentration of disaccharide in

small intestinesmall intestine

lumen lumen increased osmotic activity of the lumenincreased osmotic activity of the lumen fluidfluid

diarrhea diarrhea

b)b) Activity of disaccharidase is decreasedActivity of disaccharidase is decreased increased increased

concentration of disaccharide in small intestine lumenconcentration of disaccharide in small intestine lumen

increased concentration of disaccharide in large intestineincreased concentration of disaccharide in large intestine

disaccharide disaccharide fermentation fermentation by bacteriaby bacteria increased increased

concentration of lactic acid and fatty acids concentration of lactic acid and fatty acids

stimulation of intestine wallstimulation of intestine wall abdominal cramps, abdominal cramps,

bloating, diarrhea, acidic stools, explosive diarrheabloating, diarrhea, acidic stools, explosive diarrhea

LACTOSE INTOLERANCE:

•Many healthy people, adults and children have the inability to digest lactose.•It maybe inherited or acquired and results from a deficiency of the enzyme LACTASE.•Lactase is necessary to breakdown lactose to galactose and glucose.•Under some circumstances, the unhydrolysed sugar passes into the large intestine and gets fermented by the bacteria, inducing a laxative action.•Lactase is added in dairy products for fermentation to form yogurt, cottage cheese by changing lactose to lactic acid

Lactose Intolerance

BIFIDUS FACTOR

•Lactose accounts for 25% of the total dietary CHO.•Due to large amount of lactose in mother milk, not all is digested .•A small portion is left and fermented in the small intestine to lactic acid.•Lactic acid increases the acidity in the lower intestine which promotes the growth of a microorganism, Lactobaccilus bifidus.•This L. bifidus helps prevent the growth of other undesirable microorganism.•L. Bifidus is found mostly in breast fed infants.

Lactase deficiency syndromeLactase deficiency syndrome

Lactase deficiency syndromeLactase deficiency syndrome

Causes of lactase deficiencyCauses of lactase deficiency::

- - genetic defectgenetic defect (primary) (primary)

- secondary to a wide variety of gastrointesti- secondary to a wide variety of gastrointestinal nal

diseases diseases

that damage the mucosa of the that damage the mucosa of the smallsmall intestineintestine

(secondary)(secondary)

Disaccharide lactoseDisaccharide lactose is the principal carbohydrateis the principal carbohydrate in milkin milk..

- - Many persons showing milk intolerance prove to be Many persons showing milk intolerance prove to be

lactaselactase – – deficientdeficient - - Primary lactase deficiency incidence Primary lactase deficiency incidence is as high as 80 % is as high as 80 % to 90 % to 90 % amongamong African – AmericanAfrican – Americanss and Asians and Asians - - Milk intolerance may not become clinically apparent until Milk intolerance may not become clinically apparent until adolescenceadolescence

Causes of secondary lactase deficiencyCauses of secondary lactase deficiency: :

- - nontropical nontropical (celiac disease)(celiac disease)and tropicaland tropical sprue,sprue,

-- regional enteritis, regional enteritis,

- - viral and bacterial infections of the intestinaviral and bacterial infections of the intestinal l

tract,tract,

-- giardiasis, cystic fibrosis, ulcerative colitis, giardiasis, cystic fibrosis, ulcerative colitis,

Galactose:

Not found in nature as monosaccharide, but as a part of a disaccharide, lactose.Milk is the prime source of galactose.( milk sugar)Mammary glands convert glucose to galactose by galactose-1-phosphate uridyl transferase then synthesize lactose.

Galactosemia is an inherited disorder that affects the way the body breaks down certain sugars. Specifically, it affects the way the sugar called galactose is broken down.. The body uses glucose for energy. Because of the lack of the enzyme (galactose-1-phosphate uridyl transferase) which helps the body break down the galactose, it then builds up and becomes toxic. In reaction to this build up of galactose the body makes some abnormal chemicals. The build up of galactose and the other chemicals can cause serious health problems like a swollen and inflamed liver, kidney failure, stunted physical and mental growth, and cataracts in the eyes. If the condition is not treated there is a 80% chance that the child could die.

Treatment: All forms of milk and lactose be removed from the body.

Glycogen Storage Diseases

Glycogen storage diseases are inherited disorders that affect glycogen metabolism. Virtually all proteins involved in the synthesis or degradation of glycogen and its regulation have been discovered to cause some type of glycogen storage disease. The glycogen found in these disorders is abnormal in quantity, quality, or both. The different forms of glycogen storage disease have been categorized by number in accordance with the chronological order in which these enzymatic defects were identified

Liver and muscle have abundant quantities of glycogen and are the most commonly and seriously affected tissues. Because carbohydrate metabolism in the liver is responsible for plasma glucose homeostasis, glycogen storage diseases that mainly affect the liver usually have hepatomegaly and hypoglycemia as the presenting features.


In contrast, the role of glycogen in muscle is to provide substrates for the generation of ATP for muscle contraction. The predominant clinical features of glycogen storage diseases that mainly affect the muscle are muscle cramps, exercise intolerance, fatigue, and progressive weakness

Glycogen Sorage Diseases

Type Ia glycogen storage disease, or Von Gierke Disease, is caused by a deficiency of glucose 6-phosphatase activity in the liver and kidney with excessive accumulation of glycogen in these organs. The stored materials in the liver include both glycogen and fat. The clinical manifestations are growth retardation, hepatomegaly, hypoglycemia, lactic acidemia, hyperuricemia, and hyperlipidemia.


Type Ib glycogen storage disease is caused by a deficiency of glucose 6-phosphate translocase . The clinical features of this types are the same in type Ia with additional findings of neutropenia and impaired neutrophil function, resulting in recurrent bacterial infections and intestinal mucosa ulceration. Both type Ia and Ib genes have been cloned and mutations responsible for the diseases identified.


Type II glycogen storage disease also known as Pompe Disease is caused by a deficiency of lysosomal acid α-glucosidase in heart and liver.

Clinical features•Enlarged liver and heart•In severe cases, muscle weakness and heart problems develop•In severe cases, infants may suffer heart failure by the age of 18 months


Type III glycogen storage disease, also known Cori’s or Fobres’s disease is caused by a deficiency of glycogen debranching enzyme activity. A deficiency of debranching enzyme in liver, skeletal and cardiac muscles impairs the release of glucose from glycogen but does not affect glucose released from gluconeogenesis.

Clinical features:•Swollen abdomen due to an enlarged liver•Growth delay during childhood•Low blood sugar•Elevated fat levels in blood•Possible muscle weakness


Type IV glycogen storage disease , also known Anderson's Disease is caused by a deficiency of branching enzyme activity, which results in the accumulation of glycogen with unbranched, long, outer chains in the in liver and skeletal muscles . This form of glycogen storage disease typically presents in the first year of life

Clinical featuresGrowth delay in childhoodEnlarged liverProgressive cirrhosis of the liver (which may lead to liver failure)May affect muscles and heart in late-onset type


Type V glycogen storage disease, also known as McArdle Disease, is caused by a deficiency of muscle phosphorylase activity.

Clinical features:•Muscle cramps during exercise•Extreme fatigue after exercise•Burgundy-colored urine after exercise


Type VI and type IX glycogen storage diseases also Hers' Disease represent a heterogeneous group of diseases caused by a deficiency of the liver phosphorylase system

Clinical features:•Liver enlargement occurs, but diminishes with age•Low blood sugar


1.Type V glycogen storage disease, also known as McArdle Disease (MIM 232600), is caused by a deficiency of muscle phosphorylase activity. Symptoms usually appear in adulthood and are characterized by exercise intolerance with muscle cramps that can be accompanied by attacks of myoglobinuria.

Type VII glycogen storage disease also known Tarui's Disease is caused by a deficiency of muscle phosphofructokinase activity. The clinical features are very similar to those in type V glycogen storage disease with the notable exceptions of a compensated hemolytic anemia and early onset myogenic hyperuricemia.


cho storage diseases powerpoint

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