Nongenomic effects of androstenedione on human granulosa luteinizing cells.
This study examines rapid (5-60 s) effects of androgens on the cytosolic free Ca2+ concentration ([Ca2+]i) in human granulosa lutenizing cells. Cells were obtained from human preovulatory follicles, and [Ca2+]i was measured with the use of the Ca(2+)-responsive fluorescent dye fluo-3. Molar concentrations between 100 pmol/L and 1 mumol/L androstenedione increased [Ca2+]i within 5 s after addition to cells. This [Ca2+]i increase resulted from both Ca2+ influx, as shown by the effects of ethyleneglycol-bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid and the voltage-dependent Ca2+ channel blocker verapamil, and Ca2+ mobilization from the endoplasmic reticulum, as shown by the effects of thapsigargin. Treatment with pertussis toxin and U-73,122, a specific inhibitor of phospholipase C, abolished the effects of androstenedione on [Ca2+]i. Flutamide, a nuclear androgen receptor antagonist, did not block the increase in [Ca2+]i induced by androstenedione. Testosterone (100 pmol/L to 1 mumol/L) had no effect. This is the first report showing that androstenedione increases [Ca2+]i in granulosa cells. These data provide evidence for the presence in granulosa cells of a novel, short term mechanism of androstenedione action involving voltage-dependent Ca2+ channels in the plasma membrane and phospholipase C activation via a pertussis toxin-sensitive G protein.
Machelon
V
V
INSERM, U-355, Institut Paris-Sud sur les Cytokines, Clamart, France.
Nomé
F
F
Tesarik
J
J
D000199:Actins / Q000096:biosynthesis; D000735:Androstenedione / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005485:Flutamide / Q000494:pharmacology; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis; D006080:Ovarian Follicle; D037342:Pertussis Toxin; D016133:Polymerase Chain Reaction; D011944:Receptors, Androgen / Q000096:biosynthesis*; D013739:Testosterone / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D014700:Verapamil / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000199:Actins; D002121:Calcium Channel Blockers; D004791:Enzyme Inhibitors; D018950:Lipopolysaccharide Receptors; D011944:Receptors, Androgen; D010566:Virulence Factors, Bordetella; D013739:Testosterone; D000735:Androstenedione; D004533:Egtazic Acid; D019284:Thapsigargin; D005485:Flutamide; D014700:Verapamil; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D002118:Calcium