ENHANCED CA-45(2+) EFFLUX IN CULTURED VASCULAR SMOOTH-MUSCLE CELLS FROM SPONTANEOUSLY HYPERTENSIVE RATS

被引：13

作者：

CHEN, S ^{[1
]}

ROUFOGALIS, BD ^{[1
]}

机构：

[1] UNIV SYDNEY,DEPT PHARM,SYDNEY,NSW 2006,AUSTRALIA

来源：

AMERICAN JOURNAL OF HYPERTENSION | 1994年 / 7卷 / 07期

关键词：

SPONTANEOUSLY HYPERTENSIVE RAT; SMOOTH MUSCLE CELLS; CA2+ PUMP EFFLUX; NA+-CA2+ EXCHANGE; ANGIOTENSIN II;

D O I：

10.1093/ajh/7.7.597

中图分类号：

R6 [外科学];

学科分类号：

1002 ; 100210 ;

摘要：

Ca2+ efflux from cultured vascular smooth muscle cells (VSMC) consists of two mechanisms: one is dependent on extracellular sodium, mediated by the Na+-Ca2+ exchange (Na-0(+)-dependent Ca2+ efflux), and the other is independent of extracellular sodium but is mediated by the Ca2+ pump (Na-0(+)- independent Ca2+ efflux). In the present study we have compared these two Ca2+ effluxes in cultured aortic smooth muscle cells derived from spontaneously hypertensive rats (SHR) and Wistar-Kyoto normotensive rats (WKY). In the presence of 100 nnol/L angiotensin II both Na+-Ca2+ exchange and Ca2+-pump-mediated Ca-45(2+) efflux were enhanced significantly in SHR compared to WKY. The cellular Ca-45 content was found to be increased in SHR compared to WKY. When the data were expressed as the fraction of Ca-45(2+) lost, defined as the ratio of Ca-45(2+) lost over each time interval (5 sec) to total cellular Ca-45 content during that period, Ca2+ efflux by both mechanisms was still higher in SHR. Our results suggest that the enhanced Ca-45(2+) efflux in response to angiotensin II in SHR may be linked to greater Ca2+ uptake and possibly Ca2+ release from intracellular stores. An increase in intracellular [Ca2+](i) may be compensated for by enhanced Ca2+-pump and Na+ Ca2+ exchange activities in VSMC in hypertension.

引用

页码：597 / 602

页数：6

共 34 条

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