hCG-Induced Loss of LH-hCG Receptor and Desensitization of Adenylate Cyclase
Experimental evidence has been accumulated to support the concept that gonadotropins are involved in the regulation of their own receptors (1–2). Exposure of ovarian follicles to hCG (LH) in vivo or in vitro results in a decline in the capacity of follicles to produce cyclic AMP in response to further hCG (LH) stimulation (3,4). Direct measurement of LH-stimulated adenylate cyclase activity in ovarian follicles and corpora lutea demonstrated that desensitization is due to decreased response of adenylate cyclase to subsequent gonadotropin stimulation (5). Furthermore, studies have shown that the desensitization of hCG-sensitive adenylate cyclase is closely related to the loss of hCG receptors (6,7). The present-report demonstrates that hCG-induced loss of hCG (LH) receptors and desensitization of adenylate cyclase were both time and concentration-dependent and displayed a close correlation.
KeywordsAdenylate Cyclase Corpus Luteum Ovarian Follicle Adenylate Cyclase System Receptor Loss
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- 1.R.J. Ryan, L. Birnbaumer, C.Y. Lee, and M. Hunzicker-Dunn, International Review of Physiology. Reproductive Physiology II, Vol. 13, ed Roy O. Greep ( University Park Press, Baltimore, 1977 ) p. 85.Google Scholar
- 7.C.Y. Lee, Prog 50th Annual Meeting Endocrine Society, Chicago, 1977, Abstract #223.Google Scholar