[Sexual differences in the reaction of the thyroid gland and its sensitivity to thyrotropic hormone following administration of estradiol, testosterone and progesterone].

After the administration of estradiol benzoate (EB), testosterone propionate (TP) and progesterone (P)to Sprague-Dawley rats it was revealed that both the thyroid gland weight and the thyroxin-binding capacity of protein (TBCP) of the blood plasma were higher in the female than in the male animals. The female animals responsed to TP and P with lower values for total (TT4) and free thyrotoxin (T4)than the male animals. In the males EB elevated the level of TT4 and free T4, and in the females--the level of TT4 and TBCP. TP decreased the sensitivity of the thyroid gland to thyrotropic hormone. The stimulating effect of P on the thyroid gland resulted in its functional overstrain and exhaustion, which was stronger and more rapid in the female than in the male animals.