Xu K Y
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510.
Biochim Biophys Acta. 1992 Sep 4;1159(1):109-12. doi: 10.1016/0167-4838(92)90082-o.
Studies of the effect of strophanthidin on H(+)-transporting ATPase, Ca(2+)-transporting ATPase and H+/K(+)-transporting ATPase activities are reported. Inhibition observations and kinetic results suggest the existence of a common digitalis aglycone binding site located on the extracellular surface of the enzyme, which is affected competitively by the binding of potassium to H(+)-transporting ATPase, Ca(2+)-transporting ATPase, as well as H+/K(+)-transporting ATPase and Na+/K(+)-transporting ATPase. This may lead to a better understanding of the mechanism of the pharmacological action of cardiac glycosides and imply the possibility that the positive inotropic effect may result from the inhibition of both Ca(2+)-transporting ATPase and Na+/K(+)-transporting ATPase.
报道了毒毛旋花子苷元对H⁺转运ATP酶、Ca²⁺转运ATP酶和H⁺/K⁺转运ATP酶活性影响的研究。抑制观察结果和动力学结果表明，在该酶的细胞外表面存在一个共同的洋地黄苷元结合位点，钾与H⁺转运ATP酶、Ca²⁺转运ATP酶、H⁺/K⁺转运ATP酶以及Na⁺/K⁺转运ATP酶的结合会竞争性地影响该位点。这可能有助于更好地理解强心苷的药理作用机制，并暗示正性肌力作用可能是由于Ca²⁺转运ATP酶和Na⁺/K⁺转运ATP酶均受到抑制所致。
