钒酸盐对大鼠子宫肌层质膜酶活性的影响。

Effect of vanadate on rat myometrium plasma membrane enzyme activities.

作者信息

Grover A K, Jones T R, Daniel E E

出版信息

Can J Physiol Pharmacol. 1980 Oct;58(10):1247-50. doi: 10.1139/y80-189.

Abstract

Vanadate inhibited K+-activated and K+-activated ouabain-sensitive p-nitrophenyl phosphatases of rat myometrium at nanomolar concentrations. The vanadate concentrations required for 50% inhibition were 220 +/- 30 nM for the K+-activated component of the enzyme and 200 +/- 30 nM for the K+-activated ouabain-sensitive component. Micromolar concentrations of vanadate inhibited acid and alkaline p-nitrophenyl phosphatases. ATP-dependent Ca uptake by the plasma membrane vesicles was not inhibited by 10nM - 1 mM vanadate. Mg2+-ATPase was also not affected. Thus K+-activated and K+-activated ouabain-sensitive p-nitrophenyl phosphatase activities of the plasma membrane were most sensitive to inhibition by vanadate. Preliminary experiments demonstrated that similar to ouabain, vanadate inhibited potassium-induced abolition of spontaneous contractile activity of isolated rat myometrium in K-free Krebs. This effect of vanadate is consistent with vanadate inhibition of K+-activated ouabain-sensitive p-nitrophenyl phosphatase.

摘要

钒酸盐在纳摩尔浓度下可抑制大鼠子宫肌层的钾离子激活型及钾离子激活的哇巴因敏感型对硝基苯磷酸酶。对于该酶的钾离子激活组分，50%抑制所需的钒酸盐浓度为220±30 nM，对于钾离子激活的哇巴因敏感组分则为200±30 nM。微摩尔浓度的钒酸盐可抑制酸性和碱性对硝基苯磷酸酶。质膜囊泡对ATP依赖的钙摄取不受10 nM - 1 mM钒酸盐的抑制。镁离子ATP酶也未受影响。因此，质膜的钾离子激活型及钾离子激活的哇巴因敏感型对硝基苯磷酸酶活性对钒酸盐抑制最为敏感。初步实验表明，与哇巴因相似，钒酸盐可抑制钾离子诱导的无钾Krebs液中离体大鼠子宫肌层自发收缩活动的消除。钒酸盐的这种作用与钒酸盐对钾离子激活的哇巴因敏感型对硝基苯磷酸酶的抑制作用一致。