Prolactin release from perifused human decidual explants; effects of decidual prolactin-releasing factor (PRL-RF) and prolactin release-inhibitory factor (PRL-IF).
The dynamics of prolactin release from human decidual explants were studied under basal conditions, in response to decidual prolactin-releasing factor (PRL-RF), and in response to PRL-RF in the presence of decidual prolactin release-inhibitory factor (PRL-IF) or other factors known to inhibit prolactin release in static cultures. Explants were perifused with medium at a rate of 6 ml/h, and the medium was collected at 5 min intervals. The explants released prolactin for up to 20 h without evidence of cell necrosis, with the rate of prolactin decreasing gradually from 3.9 +/- 0.1 ng/5 min during the first 2 h to 2.2 +/- 0.1 ng/5 min during the last 2 h of exposure. PRL-RF, a 23.5 KMr protein released by the placenta, stimulated a dose-dependent increase in prolactin release from the perifused explants that occurred within the first 5 min of exposure and persisted until the exposure to the releasing factor was discontinued. PRL-IF, a 35-45 K Mr protein released by the decidua, caused a dose-dependent inhibition of PRL-RF-mediated prolactin release. Dibutyryl cAMP, cholera toxin, sn-1, 2-dioctonylglycerol, PMA, and arachidonic acid, which inhibit basal prolactin release from static decidual cultures, also caused a dose-dependent inhibition of prolactin release in response to PRL-RF. In each instance, the maximal dose of the agents tested inhibited PRL-RF-mediated prolactin release by greater than 84 per cent. These results indicate that the stimulation of prolactin by PRL-RF is inhibited by PRL-IF and pharmacologic agents that inhibit basal prolactin release.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Pediatrics, Duke University Medical Center, Durham, NC 27710.
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Handwerger
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Harman
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A
Golander
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Handwerger
D016718:Arachidonic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D003656:Decidua / Q000378:metabolism*; D004075:Diglycerides / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006801:Humans; D011388:Prolactin / Q000378:metabolism*; D011389:Prolactin Release-Inhibiting Factors / Q000494:pharmacology*; D011493:Protein Kinase C / Q000502:physiology; D011863:Radioimmunoassay; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013997:Time Factors
C011439:1,2-diacylglycerol; D004075:Diglycerides; C005071:dipalmitin; D016718:Arachidonic Acid; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D011389:Prolactin Release-Inhibiting Factors; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate