Версия сайта для людей с нарушением зрения
только для медицинских специалистов

Консультант врача

Электронная медицинская библиотека

Раздел 21 / 41
Страница 1 / 2

Lesson 20. METABOLISM OF BIOGENIC AMINES. SYNTHESIS OF NONESSENTIAL AMINO ACIDS

Questions to study.

1. Decarboxylation of amino acids and its role in the synthesis of biogenic amines. Decarboxylases of amino acids.

2. Metabolism of phenylalanine and its hereditary disorders.

3. Synthesis of dopamine, norepinephrine, epinephrine from tyrosine. Significance of catecholamines. Catabolism of catecholamines.

4. Specialized products of tryptophan, histidine and glutamate metabolism.

5. Synthesis and catabolism of serotonin, histamine, GABA, and their role.

6. Synthesis of nonessential amino acids.

Assignment for self-instruction

#

Task

Guidelines for performing the task

1

2

3

1

Study metabolism of some amino acids

1. Describe metabolism of phenylalanine and tyrosine. Explain their hereditary disorders.

2. Describe metabolism of catecholamines and indicate their significance.

3. Write down reactions of chemical conversion of some amino acids (glutamate, tryptophan, histidine).

4. Write down the structural fomula of glutathione and describe its biological significance

2

Study metabolism of biogenic amines

1. Write down reactions of synthesis of most important biogenic amines in the human body.

2. Explain the main pathway of catabolism of biogenic amines

3

Study the main pathways of amino acid synthesis

1. Specify the main precursors for synthesis of nonessential amino acids.

2. Write down the sheme of synthesis of nonessential amino acids in the body

Library-research paper

1. Modern views on the role of histamine in the development of abnormalities.

LABORATORY WORK

Quantification of histamine in blood serum

The method is based on the ability of histamine to form an orange colored complex with nitroaniline. The intensity of color, measured at 520-540 nm, is proportional to histamine concentration.

Procedure

Take two tubes: experimental and standard.

► 2 ml of blood serum is poured into the experimental tube.

► 0.2 ml of standard 0.2 mmol/l histamine solution and 1.8 ml of distilled water are poured into the standard tube.

► Add 3 ml of distilled water and 1 ml of 4% NaNO2 solution to both tubes. Shake well and place both experimental and standard tubes in a boiling water bath for 2 min.

► Withdraw both tubes and cool them with tap water.

► Add 1 ml of nitroaniline reagent to both tubes. Mix well and add 2 ml of 20% Na2CO3 solution. Mix well again.

► Cool the tubes with tap water and add 2-3 drops of 5 M NaOH solution to both tubes.

► Measure light absorbance of experimental and standard samples against distilled water at 520-540 nm using a photocolorimeter.

Calculation of histamine concentration in the blood is carried out by the formula:

Для продолжения работы требуется вход / регистрация