title: Interleukin-1 beta inhibits in vitro pulsatile progesterone secretion and stimulates prostaglandin F2 alpha secretion by micro-retrodialyzed baboon corpus luteum.
abstract: Interleukin-1 beta (IL-1 beta) modulates steroidogenesis and prostaglandin (PG) secretion by dispersed luteal cells of some non-primate species. To determine if IL-1 beta affects progesterone (P) and PGF2 alpha secretion by the baboon corpus luteum (CL), we microretrodialyzed the intact CL for 48 h; 12 h media (baseline), 12 h with IL-1 beta (3 IU/h), 12 h media only (post- IL-1 beta) and 12 h with cAMP (5 nmol/h). Four CL from the midluteal phase (LH + 8 days) were studied. P was measured by a sensitive and specific radioimmunoassay and PGF2 alpha by an enzyme immunoassay in the 10-min fractions of retrodialysates collected. P secretions were analyzed for peaks by PC Pulsar (3.0) and total P retrieved/12 h for each experimental segment was calculated. P secretion was pulsatile. Pulses of P declined from 8.2 +/- 1.2/12 h (mean +/- SEM) before to 5.0 +/- 1.2 h after IL-1 beta treatment (P = 0.022), but increased to 10.2 +/- 4.3/12 h with cAMP. Interpulse interval increased significantly from 92 +/- 23 min (baseline) to 137 +/- 31 min (p = 0.025) after IL-1 beta treatment. Total P secreted decreased significantly from 2471 +/- 515 nmol/12 h (baseline) to 1480 +/- 167 nmoles/12 h during IL-1 beta and 788 +/- 85 nmoles/12 h after IL-1 beta (P = 0.015). P was immediately suppressed after starting IL-1 beta in 2 CL but declined only towards the end of treatment in the other 2 CL. PGF2 alpha secretion increased during IL-1 beta with a further increase after IL-1 beta, while P secretion was progressively inhibited. Therefore, IL-1 beta is luteolytic to the primate midluteal phase CL by inhibiting P while simultaneously stimulating PGF2 alpha secretion, demonstrating paracrine-autocrine interaction within the luteal tissue.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Medical School at Houston, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Dawood
authors.forename: R
authors.initials: R
authors.lastname: Chellaram
authors.forename: F S
authors.initials: FS
authors.lastname: Khan-Dawood
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000378:metabolism*; D015237:Dinoprost / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000378:metabolism* / Q000494:pharmacology; D017551:Microdialysis; D010215:Papio; D010507:Periodicity; D011374:Progesterone / Q000037:antagonists & inhibitors*
chemical_list: D007375:Interleukin-1; D011374:Progesterone; D015237:Dinoprost