Angiotensin II induces calcium release in a subpopulation of single ovarian (granulosa) cells.
The effects of angiotensin II on cytosolic free Ca2+ ion concentrations ([Ca2+]i) were studied in single porcine granulosa cells using the calcium-sensitive fluorescent dye fura-2 and high temporal resolution fluorescent videomicroscopy. Angiotensin II initiated specific, rapid, transient and topographically organized increases in [Ca2+]i in a subpopulation of single swine granulosa cells. The Ca2+ source for this angiotensin II-mediated [Ca2+]i transient appeared to be internal stores, and a pertussis toxin-sensitive guanine nucleotide binding protein was implicated in this receptor-mediated Ca2+ rise. Our single-cell studies also revealed a striking functional heterogeneity among granulosa cells, since follicle-stimulating hormone-responsive cells were not angiotensin II responsive. We conclude that single swine granulosa cells are targets of specific angiotensin II action on intracellular pools of Ca2+.
Flores
J A
JA
Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
Veldhuis
J D
JD
Leong
D A
DA
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000737:chemistry; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D016257:Fura-2; D019204:GTP-Binding Proteins / Q000378:metabolism; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D008856:Microscopy, Fluorescence / Q000379:methods; D037342:Pertussis Toxin; D013552:Swine / Q000502:physiology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D010566:Virulence Factors, Bordetella; D000804:Angiotensin II; D005640:Follicle Stimulating Hormone; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D002118:Calcium; D016257:Fura-2