STRETCHING INCREASES CALCIUM INFLUX AND EFFLUX IN CULTURED PULMONARY ARTERIAL SMOOTH-MUSCLE CELLS
STRETCHING INCREASES CALCIUM INFLUX AND EFFLUX IN CULTURED PULMONARY ARTERIAL SMOOTH-MUSCLE CELLS
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DOI：
10.1152/ajplung.1992.263.5.l602
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发表时间：
1992-11-01
影响因子：
--
通讯作者：
COLUCCI, WS
中科院分区：
文献类型：
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作者：
BIALECKI, RA;KULIK, TJ;COLUCCI, WS
为了确定单次静态牵张对培养的肺动脉平滑肌细胞（PASMC）中钙通量的影响，使用Ca-45（2+）作为示踪剂，在胶原涂层硅胶膜上评价PASMC中的钙内流和外流。硅橡胶膜的单次20%线性拉伸持续1分钟，使钙摄取增加71%。这种作用被维拉帕米或钆部分抑制，但没有改变星形孢菌素，百日咳毒素，或去除细胞外钠。拉伸刺激的钙吸收随时间衰减，这样的吸收在最后一分钟的5分钟持续拉伸的46%，在拉伸的第一分钟。一个单一的20%的拉伸持续6分钟造成47%的钙外流增加，其幅度是线性相关的细胞拉伸的程度。钆和细胞外钙的去除各自部分抑制牵张诱导的钙外流。我们的结论是，一个单一的静态拉伸PASMC的原因增加钙内流和外流。牵张刺激的钙离子内流不需要钠离子内流，并且部分由对钆和维拉帕米敏感的途径介导。牵张刺激的钙外流是由于钙内流通过钆敏感的途径和动员细胞内的商店。由于钙是一个关键的细胞第二信使，这些影响的细胞钙处理的拉伸可能在调节血管平滑肌细胞的表型和功能中发挥作用。
To determine the effect of a single static stretch on calcium fluxes in cultured pulmonary arterial smooth muscle cells (PASMC), calcium influx and efflux were evaluated in PASMC on a collagen-coated silicone membrane using Ca-45(2+) as a tracer. A single 20% linear stretch of the silicone membrane of 1 min in duration increased calcium uptake by 71%. This effect was partially inhibited by verapamil or gadolinium, but was not altered by staurosporine, pertussis toxin, or removal of extracellular sodium. Stretch-stimulated calcium uptake attenuated over time, such that uptake during the last minute of a 5-min sustained stretch was 46% of that during the first minute of stretch. A single 20% stretch sustained for 6 min caused a 47% increase in calcium efflux, the magnitude of which was linearly related to the degree of cell stretch. Gadolinium and removal of extracellular calcium each partially inhibited stretch-induced calcium efflux. We conclude that a single static stretch of PASMC causes increases in both calcium influx and efflux. Stretch-stimulated calcium influx does not require sodium influx and is mediated in part by a pathway sensitive to both gadolinium and verapamil. Stretch-stimulated calcium efflux is due to both calcium influx via a gadolinium-sensitive pathway and mobilization of intracellular stores. Because calcium is a key cellular second messenger, these effects of stretch on cellular calcium handling may play a role in the regulation of vascular smooth muscle cell phenotype and function.