Some Hypothalamic Polyamines That Deplete Pituitary Follicle Stimulating Hormone

Abstract

Five polyamlne substances already known to occur naturally in mammalian tissues have been isolated from porcine hypothalamic extracts. Taken together, these substances account for most of the FSH-depleting activity of the crude extracts. Of the polyamines iso-lated, histamine is present in the highest amount. However, in the assay method used (decrease of pituitary FSH levels in intact and in castrated testosterone-treated male rats) histamine is active only at [mu]g levels; whereas putrescine, which occurs in smaller amounts, is active down to levels of a few ng. Spermidine, spermine and lysine, which have also been identified, are active at intermediate dose levels. The exact roles of the 5 amines in the turnover of pituitary FSH remain to be elucidated.