Release of luteinizing hormone in prepubertal and middle-aged ovariectomized rats.
Concentrations of circulating LH were determined in conscious, free-moving ovariectomized rats. All of the animals had been ovariectomized at 24 days of age. Between 30 and 90 days there was an increase in mean blood LH concentrations; a more vigorous pulsatile release of LH characterized by an increase in amplitude and frequency of LH release; and an elevated responsiveness to LHRH administration. Rats which had been ovariectomized for 1 year still had elevated blood LH levels but had episodic pulses of reduced amplitude and a decrease in responsiveness to LHRH. These data suggest that important alterations occur with age in the neuroendocrine mechanisms responsible for the release of LH.
D000375:Aging; D000818:Animals; D002369:Castration; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007700:Kinetics; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012741:Sexual Maturation
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone