高压氧对大鼠血管平滑肌Ca~(2 )-ATP酶活力的影响

探讨Ｃａ２＋ＡＴＰ酶在高压氧条件下对微血管作用的机理。方法：实验用Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠，雌雄均用，实验动物随机被分为：正常对照组、常压纯氧组、０．２５ ＭＰａ高压氧组和０．４ ＭＰａ高压氧组。用定磷法测定大鼠血管平滑肌Ｃａ~２＋－ＡＴＰ酶活力。结果：０．１ＭＰａ纯氧和０．２５ ＭＰａ高压氧作用后，Ｃａ~２＋ＡＴＰ酶活力增加，与正常对照组相比，０．１ＭＰａ纯氧组无显著性改变（Ｐ＞０．０５），而０．２５ＭＰａ高压氧组有非常显著的上升（Ｐ＜０．０１）；但０．４ ＭＰａ高压氧组血管平滑肌Ｃａ~２＋－ＡＴＰ酶活力下降，与正常对照组相比有显著性差异（Ｐ＜０．０５）。结论：血管平滑肌细胞Ｃａ~２＋－ＡＴＰ酶活力受高压氧作用的影响，在０．１ＭＰａ纯氧和０．２５ＭＰａ高压氧下可使酶活力增加，但过高压力的高压氧则降低其活力。

The Effect of Hyperbaric Oxygen on Ca~(2 ) -ATPase in Rats Vascular Smooth Muscle

Objective: To study the effect of Ca2 -ATPase on the vasoconstriction caused by hyperbaric oxygen(HBO). Method: Sprague-Daweley rats were randomized into: normal control group, 0. 1 MPa pure oxygen group, 0. 25 MPa hyperbaric oxygen group and 0. 4 MPa hyperbaric oxygen group. The Ca~2 -ATPase activity of vascular smooth muscle of thoracic aorta was determined by measuring the Pi released by Ca~2 -ATPase. Results: The Ca~2 ATPase activity inereased in rats exposed in 0. 1 MPa pure oxygen group and 0. 25 MPa hyperbaric oxygen group, but only in 0. 25 MPa HBO group, there was significant difference compared with normal control group. The activity of Ca2 -ATPase in rats exposed in 0. 4 MPa HBO was significantly lowered than normal group(p<0. 05). Conclusion: The hyperbaric oxygen have the effect on Ca~2 -ATPase activity in rats vascular smooth muscle. 0. 1 MPa and 0. 25 MPa HBO can increase the activity of the enzyme, but the activity of the enzyme will be lowered if the pressure is too high.