Effects of tyrosine and its analogues on hCG-induced progesterone production by rat corpus luteum in vitro
Wang, X.N.; Zhang, Q.; Gao, E.W.; Cheng, Z.P.
Chinese Medical Journal 100(11): 859-864
1987
ISSN/ISBN: 0366-6999 PMID: 3130224 Document Number: 292442
Rat corpora lutea (CL) were utilized to examine a series of tyrosine analogues for their structure-activity relationships. CL were obtained from immature rats pretreated with pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). The results indicated that hCG stimulated the production of progesterone and this effect was blocked by tyrosine. The effects of 17 analogues were compared with those of hCG and tyrosine in this system. It was shown that the essential functional groups necessary for progesterone antagonism production were the tyrosine .alpha.-amino and phenolhydroxyl groups, while the carboxyl group was seemingly essential for the antagonistic effect. Among the tyrosine analogues, tyrosine hydrazide and glycyl-tyrosine were more potent than tyrosine.