Functional state of the hypothalamus-pituitary-gonad axis in healthy men with various adaptation potential.

The characterization of the functioning of the blood circulatory system of the organism in terms of its ability to adapt to environmental conditions includes the definition of adaptive potential (AP). The purpose of the study is to supplement the idea of adaptive potential in the aspect of its association with indicators of the hypothalamus-pituitary-gonadal system in healthy men living in the climatic conditions of the Arctic zone of the Russian Federation. The study involved 94 apparently healthy men. Serum hormone levels of the hypothalamus-pituitary-gonadal system were determined by enzyme-linked immunosorbent assay. Percent of men with satisfactory adaptation was 67%. Markers of increased tension in adaptive mechanisms include a decrease in values of testosterone, sex hormone -binding globulin, and testosterone / estradiol ratio. It has been shown that in individuals with a 4-th degree of adaptive potential, the activity of the pituitary-gonadal and the pituitary-adrenal cortex systems participating in the maintenance of the circulatory system is suppressed. That may be associated with a decrease in the reserves of hormone synthesis in these systems. An increase in the tension of the adaptive mechanisms of the circulatory system occurs with a decrease in the levels of anabolic hormones and a simultaneous increase in the level of estradiol as a compensatory reaction to maintain the function of the cardiovascular system. It is established that when moving northward beyond the border of the Arctic Circle an increase in the tension of the adaptive mechanisms of the circulatory system is noted for men living in extreme climatic conditions. The results of the study show a negative correlation of adaptive potential with the values of testosterone, sex hormone-binding globulin and the testosterone / estradiol ratio. The tension of the adaptive mechanisms of the blood circulatory system occurs with decreased sex hormones levels, which can be considered as a marker of disadaptation changes amid the risk of the ecological well-being of the population.