Gender difference in the basal intracellular Ca2+ concentration in rat valvular endothelial cells.
Intracellular Ca2+ concentration ([Ca2+]i) was measured by Fura 2/AM fluorescence imaging microscopy in freshly isolated valvular endothelial cells taken from female and male rats. The basal level of [Ca2+]i was significantly elevated in female valvular endothelial cells when compared to males (P < 0.05). Inhibition of the sarco-endoplasmic reticulum Ca(2+)-ATPase with cyclopiazonic acid (CPA, 10 microM) caused a greater increase in the [Ca2+]i in female than male endothelial cells. Removal of extracellular Ca2+ returned the [Ca2+]i to the basal level. The rate of [Ca2+]i decline was significantly slower in female endothelial cells compared to males. There were no differences in the unstimulated rate of Mn2+ quenching between two groups. These results demonstrate that estrogen affects NOS at least in part, by an alteration in Ca2+ homeostasis in endothelial cells.
Vancouver Vascular Biology Research Center (VVBRC), Canada.
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Rahimian
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Wang
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van Breemen
D000818:Animals; D001021:Aortic Valve; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D004721:Endoplasmic Reticulum / Q000201:enzymology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D007211:Indoles / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008856:Microscopy, Fluorescence; D011664:Pulmonary Valve; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000201:enzymology; D012727:Sex Characteristics
D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007211:Indoles; C049925:fura-2-am; D000252:Calcium-Transporting ATPases; D002118:Calcium; D016257:Fura-2; C000543:cyclopiazonic acid