Features of changes in the content of hormones of the hypothalamic-pituitary tract depending on the independent or combined variant of B16/F10 melanoma growth in mice of both sexes

Abstract

The aim of our research work was to study changes in the level of hormones of the hypothalamus and pituitary gland in mice of both sexes in different variants of the B16/F10 melanoma growth. BALB/c Nude mice (n=84) of both sexes were divided into groups as follows: intact males and females (n=14); a reference group of mice of both sexes with standard subcutaneous B16/F10 melanoma inoculation (n=14); the main group of mice (n=14) where B16/F10 melanoma and Lewis carcinoma were inoculated into the mice sequentially subcutaneously on two sides: one on the left side, the other on the right side. At the terminal stage of the tumor growth, with ELISA using standard kits in 1% hypothalamic tissue homogenates we determined contents of releasing hormones as follows: corticotropic hormone (CRH), thyrotropic hormone (TRH), gonadotropic hormone (GnRH), somatotropic hormone (STH-R); in the pituitary with RIA determined were TSH, LH, FSH and ACTH (Immunotech, Czech Republic). Results. In males and females of both groups, the level of TRH in the hypothalamus decreased by 9-3.7 times, and only in females of the main group, the level of TSH in the pituitary gland increased by 2.8 times. Other releasing peptides in the hypothalamus of females increased by 1.9-6 times, while in males they decreased by 1.4-7 times. In the pituitary gland in males of both groups, the level of LH increased by 1.3-1.4 times and ACTH by 2.5-4 times, but FSH decreased by 7.8-13.6 times. In females, the level of FSH and ACTH in the pituitary gland decreased by 1.5 times – 1.8 times (р˂0.05), only in the main group the content of TSH increased by 2.8 times and only in the reference group LH by 1.6 times (р˂0.05). Conclusion. With the development of B16/F10 melanoma, there was a sex-dependent dysfunction of the hypothalamic-pituitary tract. Changes in the concentrations of GnRH, CRH, and STH-R in the hypothalamus in different directions in males and females indicate different mechanisms of hormonal imbalance in response to the growth of a malignant tumor.