Questions to study.
1. Hormones: their definition, classification, and biological significance.
2. Mechanism of hormone action. Target organs. Receptors. Second messengers.
3. Protein hormones. Views on mechanisms of formation of cellular response to the effect of these hormones.
4. Representatives and mechanism of the effect of hormones which bond with intracellular receptors.
5. Thyroid hormones, their classification. Thyroxin and triiodothyronine: their synthesis and catabolism, their biological effects. Mechanism of their action.
6. Disturbance of thyroid gland function. Hypothyroidism and hyperthy-roidism.
7. Parathyroid hormone: its structure and biological significance. Hypo-parathyroidism.
Assignment for self-instruction
| | Guidelines for performing the task |
| | |
| Formulate the notion of hormone, consider the classification of hormones | 1. Formulate the modern understanding of the term hormone, highlight principal features of this group of signaling molecules. 2. List endocrine glands and hormones produced by them. 3. Characterize the difference between systemic and tissue (local) hormones. 4. Write down classification of hormones according to their chemical structure and give examples. 5. Write down classification of hormones according to their influence on metabolism of proteins, lipids and carbohydrates |
Ending of the table
| | |
| Consider the basic principles of the effect of hormones on cellular metabolism | 1. List basic functions of hormones. 2. Describe the features of hormone synthesis, transport, interaction with the target cells and main effects (regulation the activity of protein, duration of their effect). 3. Characterize the term target cell and describe the features of hormone-receptor interactions |
| Consider molecular mechanisms of intracel-lular hormonal signals | 1. Describe receptors for lipid and peptide hormones. 2. Write down a scheme of the effect of lipid hormones and iodinated thyroid hormones on target cells. 3. List secondary messengers for peptide hormones. 4. Write down a scheme of hormone action via adenylate cyclase system. 5. Write down a scheme of their effects via inositol triphosphate system |
| Study iodin-ated thyroid hormones | 1. Write down the main stages of biosynthesis of iodinated thyroid hormones. 2. Characterize the features of transport of T3 and T4 in the bloodstream and interaction with receptors. 3. Consider the main physiological effects of T3 and T4 on energy metabolism, metabolism of carbohydrates, lipids and proteins. 4. Describe the diseases associated with hyper- and hypoproduction of T3 and T4 |
| Study peptide hormones of thyroid and parathyroid glands | 1. Characterize the structure of parathyroid hormone, its metabolic functions in bone tissue, kidney, and small intestine and its effect on blood calcium level. 2. Describe the structure of calcitonin and its effect on blood calcium level |
Library-research paper 1. Eucosanoids as local hormones.
LABORATORY WORK
1. Qualitative responses to thyroxin
Thyroxin (tetraiodothyronine) is a hormone of follicular portion of the thyroid gland. It is formed from thyronine amino acid and includes 4 iodine atoms:
&hide_Cookie=yes)
Procedure
Put ½ of tablet of thyroidin (preparation of dried thyroid gland containing thyroxin) in a test tube. Then add 10 drops of concentrated nitric acid. Heat the mixture in a dry box avoiding foaming. In two min, add 0.5 ml of 1% KIO3 to the test tube and stir well the contents. Then cool the mixture with tap water. 2 ml of chloroform is added and stirred well. The lower chloroform layer becomes violet.
2. Determination of calcium level in the blood
2.1. Reaction with murexid
The method is based on the ability of calcium to form a pink colored complex with murexide (complexon III). Free murexide solution colors the probe lilac.
&hide_Cookie=yes)
Procedure
► Mark two flasks as 1 and 2 before starting.
► Pour 50 ml of distilled water, 0.4 ml of 9 M NaOH solution and a few grains of murexide-containing powder into the flask 1. Mix well with a glass rod. Watch the lilac color appear.