Uehara A, Yasukochi M, Imanaga I
Department of Physiology, Fukuoka University, Japan.
J Mol Cell Cardiol. 1996 Jan;28(1):43-51. doi: 10.1006/jmcc.1996.0005.
Effects of arachidonic acid (AA) on the Ca2+ release channels in cardiac sarcoplasmic reticulum were examined by the 3H-ryanodine binding method. The samples used were membrane vesicles of junction sarcoplasmic reticulum (JSR) and solubilized ryanodine receptor proteins. AA inhibited the amount of hot ryanodine bound to its receptor in both types of samples and this inhibitory effect was dose-dependent. The Khalf values of the dose-response curve were 12 and 97 microM in the JSR membrane vesicles and the solubilized proteins, respectively. Moreover, Michaelis, Scatchard and Lineweaver-Burk analyses were performed to evaluate Kd, Bmax and Kd/Bmax values. During exposure to AA, the Kd value increased while the Bmax value decreased. These results suggest that AA directly modifies the structure of the ryanodine binding site.
采用³H-ryanodine结合法研究了花生四烯酸（AA）对心肌肌浆网中Ca²⁺释放通道的影响。所用样本为连接肌浆网（JSR）的膜囊泡和溶解的ryanodine受体蛋白。AA抑制了两种样本中与ryanodine受体结合的热ryanodine量，且这种抑制作用呈剂量依赖性。在JSR膜囊泡和溶解蛋白中，剂量反应曲线的半数抑制浓度（Khalf）值分别为12和97微摩尔。此外，进行了米氏（Michaelis）、斯卡查德（Scatchard）和林-贝氏（Lineweaver-Burk）分析以评估解离常数（Kd）、最大结合容量（Bmax）和Kd/Bmax值。在暴露于AA期间，Kd值增加而Bmax值降低。这些结果表明AA直接改变了ryanodine结合位点的结构。
