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目的研究超氧阴离子对牛主动脉平滑肌细胞内钙及收缩性的影响。方法采用Ｆｕｒａ－２测定牛肺动脉平滑肌细胞内钙及采用胶原凝胶实验方法分析平滑肌细胞的收缩性。结果超氧阴离子作用于平滑肌细胞后使ＡＴＰ（１０μｍｏｌ·Ｌ－１）诱导的细胞内钙浓度的增加从（２０６± １０） ｎｍｏｌ·Ｌ－１降到（１４７±１５） ｎｍｏｌ·Ｌ－１。 ５ ｍｉｎ内细胞内钙浓度增加的积分（∫ △［Ｃａ２＋］ｉ·ｄｔ）从（１２．２± ０．５）μｍｏｌ· Ｌ－１·ｓ－１降至（９．８± ０．８）μｍｏｌ·Ｌ－１·ｓ－１。ｔｈａｐｓｉｇａｒｇｉｎ在无钙溶液中诱导的细胞内钙浓度的增加不受超氧阴离子的影响，而在含钙的Ｋｒｅｂａ溶液中，超氧阴离子能使随后的钙释放激活的钙进入（△［Ｃａ２＋］ｉＣＲＡＣ）从（２７．３ ±１．０） ｎｍｏｌ·Ｌ－１降到（１３．５ ±１．０） ｎｍｏｌ·Ｌ－１。ＡＴＰ诱导的凝胶面积减少的百分比从２４％±５％降到 ７．４％ ±０．２％；在无钙 Ｋｒｅｂｓ溶液中，ｔｈａｐｓｉｇａｒｇｉｎ诱导的凝胶面积减少的百分比从 ３．５％± ０．６％降到－０．５％±０．７％。结论超氧阴离子通过影响平滑肌细胞的内钙动员而降低它的收缩性。
Objective To study the effects of superoxide anion on intracellular calcium and contractility of bovine aortic smooth muscle cells. Methods Fura-2 was used to determine intracellular calcium in bovine pulmonary artery smooth muscle cells and the contractility of smooth muscle cells was analyzed by collagen gel. Results The increase of intracellular calcium concentration induced by ATP (10μmol·L-1) decreased from (206 ± 10) nmol·L-1 to (147 ± 15) nmol·L-1 after treated with superoxide anion in smooth muscle cells. The integral (∫ △ [Ca2 +] i · dt) of intracellular calcium concentration decreased from (12.2 ± 0.5) μmol · L-1 · s-1 to (9.8 ± 0.8) μmol·L-1 · s-1. The increase of intracellular calcium concentration induced by thapsigargin in calcium-free solution is not affected by superoxide anion, whereas in calcium-containing Kreba solution, the superoxide anion causes subsequent calcium release-activated calcium to enter (Δ [Ca 2+] i CRAC ) Decreased from (27.3 ± 1.0) nmol·L-1 to (13.5 ± 1.0) nmol·L-1. The percentage of ATP-induced gel area reduction decreased from 24% ± 5% to 7.4% ± 0.2%; the percentage of thapsigargin-induced gel area reduction in calcium-free Krebs solution decreased from 3.5% ± 0 .6% down to -0.5% ± 0.7%. Conclusions Superoxide anion reduces its contractility by affecting the mobilization of calcium from smooth muscle cells.