Growth hormone-releasing factor (GRF) stimulates PGE2 production in rat anterior pituitary. Evidence for a PGE2 involvement in GRF-induced GH release.
Rat anterior pituitaries were incubated over a 3-h period. Both PGE2 and GH were increased by GRF in a concentration-related manner (ED50: 3.5 nM and 6.5 nM, respectively). A significant correlation (r = 0.88, n = 127) was observed between GH and PGE2 release over the range of GRF concentrations tested. Among the five prostanoids analyzed, only PGE2 was selectively increased. Somatostatin lowered GH release, without any effect on PGE2 production. Indomethacin (Id) and Aspirin reduced significantly PGE2 synthesis and GRF-induced GH release. The inhibitory effect of Id was counteracted by addition of PGE2 to the medium. GRF and PGE2, at maximal concentrations, had a partial additive effect on GH release. The increase in PGE2 production and the reduced GH release in the presence of cyclooxygenase inhibitors suggest that PGE2 is involved in GRF-induced GH release.
Fafeur
V
V
Gouin
E
E
Dray
F
F
D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D015232:Dinoprostone; D013006:Growth Hormone / Q000096:biosynthesis / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000502:physiology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis; D011458:Prostaglandins E / Q000096:biosynthesis* / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000494:pharmacology; D013931:Thromboxanes / Q000096:biosynthesis
D011453:Prostaglandins; D011458:Prostaglandins E; D013931:Thromboxanes; D013004:Somatostatin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D015232:Dinoprostone; D001241:Aspirin; D007213:Indomethacin