Influence by hypothyroidism on the level of sex hormones in blood and their intracrine content in the tumor in rats with Guerin's carcinoma

The aim of our research work was to study the level of sex steroids in blood, the tumor and the perifocal zone in rats of both sexes with Guerin’s carcinoma against the background of hypothyroidism. Materials and methods. The experiment was performed in 110 outbred rats of both sexes. Hypothyroidism was induced in animals for 30 days with Mercazolil medication, and then Guerin’s carcinoma was transplanted (the main group). The reference groups included animals with an independent growth of Guerin’s carcinoma and with independent hypothyroidism, as well as intact animals (the norm). On the 18th day of the tumor growth, the animals were sacrificed, and, using standard RIA kits, in the serum, the tumor homogenates and the perifocal zone, the levels of estradiol (E2), testosterone (T) and progesterone (P4) were determined. Results. In comparison with intact animals, hypothyroidism caused an increase in the blood content of E2 in animals of both sexes by 2.2-2.4 times and T by 1.4-16 times, and P4 by 1.7 times only in females, but recorded was a decrease therein in males by 2.4 times. The growth of Guerin’s carcinoma resulted in a 2.5-5.5-fold decrease in E2 in blood of the animals of both sexes, an increase in T by 2.1 times and P4 by 3 times in the females, but a decrease in T by 2.6 times without changing P4 in the males. In the main group, in the animals of both sexes, similarly to the processes in hypothyroidism, the level of E2 and P4 increased by 1.4-1.6 times, and in females also T by 4.4 times, compared with the intact animals. Conclusion. Hypothyroidism and the growth of Guerin’s carcinoma changed E2 in different directions in animals of both sexes the level of sex hormones in blood and shifted the steroid balance in the tumor and its perifocal zone. In the females of the main group, the saturation of the tumor with estrogens, androgens and progesterone decreased, while in the males, on the contrary, the concentration of steroids increased.