Luteal Production of Steroids and Prostaglandins during Simulated Early Pregnancy in the Primate: Differential Regulation of Steroid Production by Chorionic Gonadotropin1

Abstract

Stimulation of the primate corpus luteum (CL) by endogenous chorionic gonadotropin (CG) in early pregnancy, or by exogenous human (h)CG in simulated early pregnancy, results in a transient elevation of serum progesterone (P) and a persistent elevation of serum 17 beta-estradiol (E). Luteal prostaglandins (PG) may play a role in these responses. The objective of the current study was to correlate luteal PG production and steroidogenic response of CL in vitro with patterns of serum steroids during simulated early pregnancy. CL were removed from rhesus monkeys (n = 26) at 0 h, 9 h, 3 days, 6 days, and 10 days, during prolonged CG exposure of simulated early pregnancy. Dispersed cells were incubated in vitro at 37 degrees C for 8 h. Changes in basal production of P were not significantly correlated with patterns of serum steroids. Maximal stimulation of P production by hCG in vitro (stimulated minus basal) continuously declined (p less than 0.01) from 0 h (means +/- SE, 59.6 +/- 17.9 ng/ml) to 10 days (4.7 +/- 1.8 ng/ml) of simulated early pregnancy. In contrast to patterns of response to hCG, the level of enhancement in P production in response to a maximally stimulatory dose of dibutyryl (db) cyclic adenosine 3',5'-monophosphate (cAMP) declined (p less than 0.05) from 0 h (52.4 +/- 17.6 ng/ml) to 3 days (20.3 +/- 8.4 ng/ml), but was maintained through 10 days (23.7 +/- 11.6 ng/ml) of simulated early pregnancy. As such, desensitization to gonadotropin, which occurred in terms of P production, appears to involve an event subsequent to stimulation of adenylate cyclase.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Diets Containing Gossypol on Reproductive Capacity of Rainbow Trout (Oncorhynchus mykiss)1

“…Plasma steroid hormones (testosterone [T], estradiol-17␤ [E 2 ], 11-ketotestosterone [11-kT], and 17,20␤-dihydroxy-4-pregnen-3-one [17,20␤P]) were determined by RIA according to methods similar to those of Ottobre et al [24]. The steroids were previously extracted with ethyl ether.…”

Effect of prostaglandins on luteal function during early pregnancy in pigs

“…During early pregnancy, days 13-17, endogenous uterine PGF2u secretion into the uterine vein is reduced (Gleeson et ai, 1974;Moeljono et ai, 1977), and luteal PGF2a receptor concentrations are considerably lower than in nonpregnant pigs (Gadsby et ai, 1990). However, the corpus luteum of cows (Shemesh & Hansel, 1975;Milvae & Hansel, 1983;Pate, 1988), ewes (Rexroad & Guthrie, 1979), women (Challis et al, 1976), mares (Watson & Sertich, 1990), monkeys (Johnson et al, 1988;Ottobre et al, 1989), rabbits (Schlegel et al, 1988;Schlegel & Daniels, 1989) and cyclic (Patek & Watson, 1976;Walker et al, 1977;Guthrie et al, 1978) or pregnant pigs (Watson & Patek, 1979; Guthrie & Rexroad, 1981) can synthesize prostaglandins.…”

Relationship between vitamin C and plasma concentrations of testosterone in female rainbow trout, Oncorhynchus mykiss

“…AA was estimated colorimetrically with correction for interferences (Dabrowski and Hinterleitner 1989). Plasma E 2 and T concentrations were analyzed by radioimmunoassays similar to those used previously (Ottobre et al 1989). The estrogen antibody has been characterized previously by Dr. Roy Butcher, West Virginia University (Butcher et al 1974).…”