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

[11]

Smith J.B., Brock T.A., Analysis of angiotensin-stimulated sodium transport in cultured smooth muscle cells from rat aorta, J Cell Physiol, 114, pp. 280-290, (1983)

[12]

Ross R., The smooth muscle cell. II. Growth of smooth muscle in culture and formation of elastic fibers, J Cell Biol, 50, pp. 172-186, (1971)

[13]

Smith J.B., Smith L., Brown E.R., Et al., Angiotensin II rapidly increases phosphatidate-phosphoinositide synthesis and phosphoinositide hydrolysis and mobilizes intracellular calcium in cultured arterial muscle cells, Proc Natl Acad Sei USA, 81, pp. 7812-7816, (1984)

[14]

Dulley J.R., Griene P.A., A simple technique for eliminating interference by detergents in the Lowry method of protein determination, Anal Biochem, 64, pp. 136-141, (1975)

[15]

Furukawa K.-I., Tawada Y., Shigekawa M., Protein kinase C activation stimulates plasma membrane Ca2 + pump in cultured vascular smooth muscle cells, J Biol Chem, 264, pp. 4844r-4849r, (1989)

[16]

Van Breemen C., Cellular mechanisms regulating [Ca2+]j smooth muscle, Annu Rev Physiol, 51, pp. 315-329, (1989)

[17]

Dawson A.P., Regulation of intracellular Ca2+, Essays Biochem, 25, pp. 1-37, (1990)

[18]

Matlib M.A., Schwartz A., Yamori Y., A Na + -Ca2+ exchange process in isolated sarcolemmal membranes of mesenteric arteries from WKY and SHR rats, Am J Physiol, 249, pp. C166-C172, (1985)

[19]

Ashida T., Kuramochi M., Omae T., Increased sodium-calcium exchange in arterial smooth muscle of spontaneously hypertensive rats, Hypertension, 13, pp. 890-895, (1989)

[20]

Hojo Y., Ebata H., Ikeda U., Et al., Enhanced spontaneous calcium efflux and decrease of calcium-dependent calcium release from the isolated perfused heart of spontaneously hypertensive rats, J Hypertens, 10, pp. 513-520, (1992)

← 1 2 3 4 →