Effects of sodium nitroprusside on cytosolic calcium level in vascular smooth muscle.
Effects of sodium nitroprusside on cytosolic calcium level in vascular smooth muscle.
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DOI：
10.1016/0014-2999(88)90329-9
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发表时间：
1988-11
影响因子：
5
通讯作者：
Hideaki Karaki;Koichi Sato;H. Ozaki;Kazuyasu Murakami
中科院分区：
文献类型：
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作者：
Hideaki Karaki;Koichi Sato;H. Ozaki;Kazuyasu Murakami
硝普钠对细胞质 Ca2+ 水平 ([Ca2+]cyt) 的抑制作用（通过荧光染料 fura-2 在收缩的同时进行测量）以及对离体大鼠主动脉平滑肌中 45 Ca2+ 摄取的抑制作用进行了测试。去甲肾上腺素增加肌张力、45Ca2+摄取和[Ca2+]细胞色素。在 Ca2+ 缺乏的溶液中，去甲肾上腺素会短暂增加肌肉张力和 [Ca2+] 细胞色素。硝普钠抑制去甲肾上腺素引起的所有变化，但对[Ca2+]细胞的抑制作用小于对肌肉收缩的抑制作用。硝普钠还可以抑制高钾诱导的收缩，其浓度高于抑制去甲肾上腺素诱导的收缩所需的浓度。高K+诱导的收缩的抑制伴随着[Ca2+]细胞的小幅减少和45Ca2+摄取的较小减少。亚甲基蓝具有拮抗作用，M & B 22,948 增强硝普钠的抑制作用。这些结果表明硝普钠具有多个作用位点。在较低浓度下，硝普钠可以抑制Ca2+内流和Ca2+释放。在相对较高的浓度下，该抑制剂还可以增强 Ca2+ 隔离并降低收缩元件对 Ca2+ 的敏感性。
The inhibitory effect of sodium nitroprusside on the cytosolic Ca2+level ([Ca2+]cyt), measured simultaneously with contraction by means of a fluorecence dye, fura-2, and on the45Ca2+uptake was tested in the isolated rat aortic smooth muscle. Norepinephrine increased muscle tension,45Ca2+uptake and [Ca2+]cyt. In a Ca2+-deficient solution, norepinephrine transiently increased muscle tension and [Ca2+]cyt. Sodium nitroprusside inhibited all changes induced by norepinephrine although the inhibition of [Ca2+]cytwas less than that of muscle contraction. Sodium nitroprusside also inhibited the high K+-induced contraction at concentrations higher than those needed to inhibit norepinephrine-induced contraction. Inhibition of the high K+-induced contraction was accompanied by a small decrease in [Ca2+]cytand a smaller decrease in45Ca2+uptake. Methylene blue antagonized, and M & B 22,948 potentiated the inhibitory effect of sodium nitroprusside. These results suggest that sodium nitroprusside has multiple sites of action. At relatively low concentrations, sodium nitroprusside could inhibit the Ca2+influx and Ca2+release. At relatively high concentrations, this inhibitor could also augment Ca2+sequestration and decrease the sensitivity of contractile elements to Ca2+.