Effect of Sex Hormones on Feed Intake in Rats

Publisher Website
Google Scholar
Abstract
A series of five experiments was made in which intact or gonadectomized male and female rats were given sex hormones to determine the influence of these agents on feed intake. Diethylstilbestrol and ethinyl estradiol (estrogenic compounds), 6-chloro-6-dehydro-17α-acetoxy progesterone, progesterone and testosterone were used. Estrogens resulted in a significant reduction in feed intake in weanling or adult, intact or gonadectomized, males or females. The extent of reduction was greater in adults than in weanlings but was never total. The reduction in adult females did not persist, although it was greater initially than in weanlings. In weanling adrenalectomized intact or castrated males, estrogen was not effective in reducing intake, whereas when the treatment of estrogen was started with adults, a significant reduction in intake occurred. Intake was not affected by feeding testosterone at a 5 or 500 mg/kg diet, nor did progesterone affect intake when fed at up to 3 mg/kg diet or injected at up to 1 mg/rat/day. Progesterone did not overcome the depression in intake caused by estrogen when the ratio of exogenous estrogen: progesterone additions was within the range 1:800 to 1000. Removal of the testes caused a reduction of intake in males with or without adrenals, while removal of the ovaries caused intake to increase in females. Intake is depressed by estrogenic hormones. The adrenal gland seems to be involved in the expression of the depressing effect of estrogenic materials.