[Reactions of the adreno-hypothalamo-hypophyseal system in rats chilled in a hypoxic-hypercapnic gaseous medium]. / Reaktsii sistemy nadpochechniki-gipotalamus-gipofiz u krys, okhlazhdennykh v usloviiakh gipoksichesko-giperkapnicheskoi gazovoi sredy.

The rearrangement of the adrenal-hypothalamus-pituitary system of rats kept in a low-temperature hypoxic-hypercapnic atmosphere was investigated. Phasic changes of the system were detected, with their magnitude and sign depending on the exposure time. The central and peripheral components of the system developed specific relations. One of the peculiarities of the responses of the adrenal-hypophysis-pituitary system to the above exposure is a limited range of changes in the neuroendocrine activities due to a total reactivity decrease. This protects the neuroendocrine system from overstrain or involvement in overshooting reactions. It is assumed that this type of response of the adrenal-hypophysis-pituitary system is important to help understand mechanisms of the neuroendocrine regulation of the adaptive process developing in response to the combined effect.

[Effect of a hypoxic-hypercapnic gaseous medium and lowered temperature on the functional state of the rat hypothalamo-hypophyseal-thyroid system]. / Vliianie gipoksichesko-giperkapnicheskoi gazovoi sredy i snizhennoi temperatury na funktsional'noe sostoianie u krys sistemy gipotalamus-gipofiz-shchitovidnaia zheleza.

Radioimmunoassay and morphometry were used to study the time course of the function of the hypothalamus-pituitary-thyroid system in rats cooled under the conditions of the increasing hypoxia-hypercapnia. The changes in the function of this system exposed to combined factors were phasic in nature. The trend of the changes and functional activity of the test system depended, at individual times of cooling, on the pattern of environmental factors and reconstitution of the general body reactivity. It is suggested that the changes in the function of the hypothalamus-hypophysis-thyroid attest to the involvement of this part of the endocrine system in the body response to cooling and are thus one of the essential components in neuroendocrine regulation of the adaptive process responsible for the increased resistance of the animals to the exposure to extremal environmental factors.