An unexpected increase in pituitary sensitivity to gonadotrophin releasing hormone after treatment with porcine follicular fluid (inhibin) in immature hemicastrate rats.
Porcine follicular fluid (PFF) contains a factor (inhibin or folliculostatin) which is reported to selectively inhibit the secretion of follicle-stimulating hormone (FSH) from the anterior pituitary gland. Chronic treatment of hemicastrate immature rats with PFF is able to partially inhibit the FSH-mediated hypertrophy of the remaining testis. However, the pituitaries from PFF-treated rats are paradoxically very sensitive to stimulation with gonadotrophin-releasing hormone (GnRH) and secrete significantly more FSH than control glands. Furthermore, this increased sensitivity results in a large increase in luteinizing hormone (LH) secretion. These observations suggest that under certain circumstances PFF is not selective for FSH and that it surprisingly stimulates rather than inhibits gonadotrophin secretion.
D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology* / Q000627:therapeutic use; D007265:Inhibins; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D006080:Ovarian Follicle / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D011506:Proteins / Q000627:therapeutic use*; D051381:Rats; D013552:Swine; D013737:Testis / Q000502:physiology*
D011506:Proteins; D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone