Growth hormone release after synthetic 1-24 ACTH: effects of estrogen and sex.

Recent reports have demonstrated that growth hormone (GH) is inconsistently released after intravenous administration of synthetic 1-24 ACTH. This study was designed to evaluate the role of estrogens in mediating this response. 250 mug of synthetic 1-24 ACTH were administered to 8 men in 12 studies and 6 women in 11 studies. None of the men exhibited a rise in GH after 1-24 ACTH, while the women exhibited a significant increase. Pretreatment of 5 of these men with 100 mug of ethinyl estradiol daily for 3 days did not alter GH response from the initial studies. Pretreatment with 10 mg of diethylstilbesterol daily for 3 days, however, resulted in a rise in GH which was similar to the female group. It is concluded that the variable GH responses to synthetic 1-24 ACTH may be in part due to prevailing concentrations of sex steroids and their effect on the hypothalamic-pituitary GH release mechanism.