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Prostaglandin Production by Corpora Lutea of Rhesus Monkeys: Characterization of Incubation Conditions and Examination of Putative Regulators1

1988; Oxford University Press; Volume: 39; Issue: 4 Linguagem: Inglês

10.1095/biolreprod39.4.839

1529-7268

M. Johnson, A. C. Ottobre, J.S. Ottobre,

Ovarian function and disorders

Prostaglandins (PGs) are produced by the corpus luteum (CL) of many domestic and laboratory species and may play a role in CL regulation. The production of PGs by luteal tissue of the rhesus monkey has yet to be clearly elucidated. The production of PGE2, PGF2α, and 6-keto-PGF1α by CL from rhesus monkeys and the incubation conditions (time and cell number) that permit assessment of their synthesis were examined. CL (n = 3 per characterization) were surgically removed from nonpregnant monkeys during the mid-luteal phase of the menstrual cycle (~ 8–10 days after ovulation). Luteal tissue was dissociated and the cells were incubated at varying concentrations for increasing periods of time at 37°C. Subsequent to defining incubation conditions, various exogenous factors were examined for their potential to modify PG production. Indomethacin, calcium ionophore, human chorionic gonadotropin (hCG), estradiol-17β (E2), progesterone (P), testosterone (T), dihydrotestosterone (DHT), and 1–4–6 androstatriene-3, 17-dione (ATD) were incubated with luteal cells in increasing doses. PG and P concentrations in the medium were determined by radioimmunoassay. PGs in the medium after 6 h incubation were detectable at all cell concentrations tested (50,000, 100,000, 200,000 cells/tube). Concentrations of PGs and P increased with cell number (p<0.05). Luteal cells (50,000 cells/tube) were incubated for times of 0–24 h. Concentrations of P, PGE2, and PGF2α in the medium were relatively low prior to incubation (0 h), increased (p<0.05) linearly within the first 6–12 h, and plateaued through the remaining 24 h. A similar pattern was observed for concentrations of 6-keto-PGF1α. Incubation times of 6–12 h were deemed appropriate for subsequent studies as they provided PG concentrations detectable and above baseline (0 h). Indomethacin, a PG-synthesis inhibitor, decreased concentrations of PGs in the medium in a dose-dependent manner (p<0.05). The highest dose of indomethacin prevented any increase in concentrations of PGs above the levels prior to incubation. There was no effect on P concentrations. Conversely, hCG had no effect on PG production but stimulated P production in a dose-dependent manner (p<0.05). Calcium ionophore, a stimulator of PG synthesis, increased PGF2α, PGE2 (p<0.01), and 6-keto-PGF1α (p<0.05) in a dose-dependent manner. Other hormones (T, P, E2, DHT, ATD) did not influence P and PG production, and thus had no acute effect on luteal function in vitro. The observations made in this study substantiate that the CL of the rhesus monkey synthesizes PGs. Further studies are necessary to identify and define the roles that luteal PGs may play in the regulation of the primate CL.