title: Positive feedback of gonadotropins in males.
abstract: The influence of estradiol and progesterone upon serum LH and FSH has been evaluated in three groups of five normal adult males. These steroids were administered to ascertain whether the hypothalamus and pituitary in the male possesses the capability for acute release and positive feedback of gonadotropins, a well established characteristic of the hypothalamus and pituitary in the female. Suppression of circulating levels of gonadotropins occurred after the oral administration of 0.1 mg of ethinyl estradiol daily for three days to experimental group 1, and after 0.1 mg ethinyl estradiol given daily for nine days plus 1.0 mg given on day 10 to experimental group 2. Positive feedback of serum LH levels occurred in two of five men of experimental group 3 after they received 0.5 mg ethinyl estradiol orally daily for three days. Three men had a rise of FSH concentration between day 5 and 8 of the administration of this drug. Ten mg of progesterone (IM) given to these men after suppression with estradiol also produced a positive feedback of FSH in three and of LH in four of the five men.
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005246:Feedback; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D011374:Progesterone / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone