[Biochemical and clinical aspects of melatonin biosynthesis induced by noradrenalin in experiment].

Melatonin has been considered as a hormone with potent immunomodulating, anxiolitic and antioxidative properties. Melatonin is also known to be inhibitor of sympatoadrenal activity. The study was aimed to elucidate changes in melatonin synthesis induced by noradrenalin IM injection. Melatonin plasma levels were detected by radioimmunoassay. All studies were performed conducted on white non-linear rats. By the 20th day after noradrenalin administration plasma level of melatonin was significantly decreased. In conclusion, short-term activation of sympatoadrenal system (i.e. stress-induced activation) is accompanied by elevated plasma levels of melatonin, however long-term hyperactivity of the sympatoadrenal system atrophy of epiphiseal parenchyma develops followed by decreased melatonin synthesis. It has been considered that melatonin might contribute to chronic stress-induced process associated with involution of thymus and lymphatic nodes, hypertrophy of adrenal cortex. Data obtained might be taken into consideration during the treatment of stress-induced conditions.

[Biochemical, pharmacological and clinical aspects of influencing methioninc, tryptophan, pyridoxine (vitamin B6), Ca2+ and high-calorie food on the synthesis and intensity of the secretion of melatonin].

The goal of the investigation was the determination of the influence of Ca(2+), vitamin B6 methionine, tryptophan, the combination of the listed elements and high-calorie food on the intensity of synthesis and secretion of melatonin. The level of melatonin in the blood serum was being determined through the method of radio-immune (immune-enzyme) analysis. Based on the results received it was found out that the influence of the vitamin B6, tryptophan and their combination in the organism of the tested objects - white rats) resulted in the considerable increase of formation of melatonin. In the conditions of feeding them with high-calorie food - the value of melatonin in blood is sharply reducing. Consequently we may conclude that the vitamin B6 and tryptophan separately and in combination, either directly or through some other mechanism participate actively in biosynthesis and secretion of melatonin. The high-calorie food through unknown mechanism to us reduces the formation of the melatonin in epiphysis. This might point to the important role of the deficit of melatonin in etiopathogenesis of the diseases, detected and developed on the background of hypercholesterinemy.