Zhang Y, Abdel-Latif A A
Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912-2100.
Cell Signal. 1992 Nov;4(6):777-86. doi: 10.1016/0898-6568(92)90058-g.
The stimulation of phospholipase D (PLD) activity by endothelin-1 (ET1) was investigated in rabbit iris sphincter prelabelled with [3H]myristic acid. In the presence of 0.5% ethanol, ET1 caused a time- and dose-dependent increase in the production of [3H]phosphatidylethanol ([3H]PEt). Within 30 s the peptide increased PEt formation by 30% and after 5 min increased it by 140%. The EC50 value for ET1-stimulated PEt formation was found to be 30 nM. This value is appreciably lower than the EC50 we previously obtained for ET1-induced inositol trisphosphate production (45 nM), but considerably higher than that for arachidonic acid release (1 nM). PEt formation was significantly stimulated by prostaglandin F20, phorbol 12,13-dibutyrate (PDBu), chloroform, A23187 and A1F4-, but it was not affected by carbachol or the platelet-activating factor. PDBu-stimulated PEt formation was blocked by staurosporine and it was not potentiated by A23187. Staurosporine had no effect on ET1-stimulated PEt formation. Our data indicate that ET1 stimulation of PLD occurs independently of protein kinase C activation, phospholipase C activation and intracellular Ca2+ mobilization, and phospholipase A2 activation. In this tissue the ET1 receptor is probably coupled to the three phospholipases through several G-proteins, and this appears to be species and receptor type specific.
在内皮素-1（ET1）刺激下，对预先用[3H]肉豆蔻酸标记的兔虹膜括约肌中磷脂酶D（PLD）活性进行了研究。在存在0.5%乙醇的情况下，ET1引起[3H]磷脂酰乙醇（[3H]PEt）生成的时间和剂量依赖性增加。在30秒内，该肽使PEt形成增加30%，5分钟后增加140%。发现ET1刺激PEt形成的EC50值为30 nM。该值明显低于我们之前获得的ET1诱导肌醇三磷酸生成的EC50（45 nM），但远高于花生四烯酸释放的EC50（1 nM）。前列腺素F2α、佛波醇12,13-二丁酸酯（PDBu）、氯仿、A23187和AlF4-可显著刺激PEt形成，但卡巴胆碱或血小板活化因子对其无影响。PDBu刺激的PEt形成被星形孢菌素阻断，且不受A23187增强。星形孢菌素对ET1刺激的PEt形成无影响。我们的数据表明，ET1对PLD的刺激独立于蛋白激酶C激活、磷脂酶C激活、细胞内Ca2+动员和磷脂酶A2激活。在该组织中，ET1受体可能通过几种G蛋白与这三种磷脂酶偶联，这似乎具有物种和受体类型特异性。
