Lesson 27. HORMONES OF PANCREAS AND ADRENAL GLAND. DIABETES MELLITUS

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Task

Guidelines for performing the task

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Study

the structure and biochemical importance of insulin

1. Describe the features of insulin structure and biosynthesis. List the factors that regulate insulin synthesis and secretion.

2. Describe the structure of insulin receptor.

3. Write down the effects of insulin on the key regulatory (rate-limiting) enzymes of glycolysis, glycogenesis, pentose phosphate pathway, TCA cycle, lipogenesis, protein translation.

4. Write down a scheme of molecular mechanism of intracellular steps of insulin signaling

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Consider metabolic disorders in diabetes mellitus

1. Name clinical types of diabetes mellitus. What is the difference between

them?

2. Write down principal signs of diabetes mellitus.

3. Explain why in diabetes mellituse blood glucose cannot be utilized properly. Name the enzymatic blocks in glycolysis and glucogenesis.

4. Explain the mechanism of glycosylation of proteins in diabetes mellitus.

5. Find out about the causes, mechanisms and consequences of enhancing of lipolysis and fatty acid ß-oxidation in diabetes mellitus.

6. What causes disturbances in utilization of acetyl-CoA in diabetes mel-litus? Explain the causes of ketonemia and ketonuria development.

7. Explain why insulin deficiency leads to disturbance of biosynthesis

of nucleic acids and proteins, and enhanced tissue proteolysis and accelerated catabolism of amino acids.

8. Define the terms glycemic profile and renal glucose threshold.

9. Name current biochemical tests that are used in diagnosis of diabetes mellitus

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Study

the structure and biochemical significance of glucagon

1. Describe the structure and metabolic effects of glucagon on carbohydrate metabolism and neutral fat.

2. Describe the mechanism of glucogon effect on metabolism

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Study adrenal

medullary

hormones

1. Write down reactions of biosynthesis of norepinephrine and epinephrine from tyrosine.

2. Name the physiological effects of norepinephrine and epinephrine.

3. Name the biochemical effects of epinephrine in the liver, muscle and adipose tissues.

4. Make a schematic representation of the effects of adenylate cyclase system in mobilizing of glycogen and neutral fat upon interaction of epinephrine with ß-adrenoreceptors

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Consider

adrenal

hormones

1. List the main groups of adrenal hormones.

2. What is the precursor of all adrenal hormones? Name the areas of the adrenal cortex which produce them.

3. List the transporters of adrenal hormones in the bloodstream.

4. List the principal glucocorticoids and write down their formulas.

5. Describe the effects of glucocorticoids on carbohydrate metabolism and name the rate-limiting enzymes of gluconeogenesis controled by glucocor-ticoids.

6. Describe the features of glucocorticoid effects on the metabolism of proteins and lipids.

7. Explain of autonomic self-regulation of the hypothalamic-pituitary-adrenal axis

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8. Write down the formula of aldosterone and describe its effect on water-salt metabolism. Describe the mechanism of regulation of aldocterone secretion.

9. Consider the disorders of aldosterone secretion

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Consider tissue hormones

1. Characterize the structure and biological significance of gastrointestinal hormones - gastrin, secretin and others.

2. Describe features of the structure, production and regulation of synthesis of erythropoietin. What is its biological significance?

3. Characterize the structure and biological significance of leptin and other fat-tissue hormones

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Study hormones -deriva-tives of poly-usaturated fatty acids (PUFA, eicosanoids)

1. Consider distinctive features of the structure, nomenclature, classification and pathway of synthesis of prostaglandins and leukotrienes.

2. Describe the role of these compounds in regulating physiological processes - vascular smooth muscle tonicity, platelet aggregation, nephron function, etc.

3. Explain the mechanism of effects of medicines like aspirin, nonsteroid antiinflammatory drugs (NSAIDs), etc., on biosynthesis of prostaglandins.

4. Write down the formulas of prostaglandin A₂, thromboxane A₂ and leukotriene A₄