Stimulation of release and synthesis of luteinizing hormone (lh) and follicle stimulating hormone (fsh) in tissue cultures of rat pituitaries in response to natural and synthetic lh and fsh releasing hormone

Addition of nanogram amounts of highly purified or pure porcine LH-RH/FSH-RH, once daily for 5 days to female rat anterior pituitary cultures, significantly increased the release of both LH and FSH. LH release appeared to be linearly related to the log-dose of LH-RH/FSHRH over the range of S-40 ng/ml/day. Total content of LH and of FSH in stimulated tissue and medium exceeded that of controls as measured by radioimmunoassays for LH and FSH. Synthetic LH-RH/FSH-RH also stimulated the release and synthesis of both LH and FSH in rat anterior pituitary cultures. This indicates that both LH and FSH releasing activities are intrinsic to the same molecule. When anterior pituitary tissue was incubated with tritiated glucosamine in the presence of porcine LH-RH/FSH-RH, there was a significant incorporation of radioactivity into the LH found in the incubation medium. These data indicate that de novo synthesis, as well as release of LH, occurred in tissue stimulated with porcine LH-RH/FSH-RH.