Effect of beta-endorphin on cAMP accumulation in rat luteal cells.
The effect of beta-endorphin on cAMP levels in 4-day-old rat luteal cells was investigated. In both the presence and absence of low doses of human chorionic gonadotropin (hCG, 0.001 IU/ml), beta-endorphin inhibited cAMP accumulation, whereas in the presence of high doses of hCG (0.01 IU/ml) it did not. This inhibitory effect was abolished by pre-treatment with islet-activating protein (IAP). Moreover, treatment with IAP resulted in an overall enhancement of hCG-stimulated cAMP accumulation when compared with untreated controls. These results suggest that beta-endorphin suppresses adenylate cyclase activity via Gi, which may be coupled to the LH receptor.
Kato
T
T
Department of Endocrinology, Tokyo Medical and Dental University, Japan.
Kumai
A
A
Okamoto
R
R
D037361:Adenylate Cyclase Toxin; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis / Q000378:metabolism*; D005260:Female; D019204:GTP-Binding Proteins / Q000187:drug effects / Q000502:physiology; D007700:Kinetics; D008184:Luteal Cells / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical; D013997:Time Factors; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D001615:beta-Endorphin / Q000494:pharmacology* / Q000502:physiology
D037361:Adenylate Cyclase Toxin; D006063:Chorionic Gonadotropin; D010566:Virulence Factors, Bordetella; D001615:beta-Endorphin; D000242:Cyclic AMP; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins