Kaul D, Singh J
Experimental Medicine Department, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
Cell Signal. 1994 Feb;6(2):141-5. doi: 10.1016/0898-6568(94)90070-1.
Incubation of gel-filtered human platelets with cholesterol in the absence of divalent ions revealed that exogenous cholesterol had the ability to down-regulate the cholesterol biosynthesis in a dose-dependent fashion and this phenomenon was paralleled by an increase in phospholipase D activity. However, exogenous calcium in the presence of either cholesterol or phosphatidic acid had the capacity to up-regulate the platelet cholesterol synthesis in a dose-dependent manner. Further, cyclic nucleotides (cAMP, cGMP) also had the ability to influence directly the regulation of platelet cholesterol synthesis. Based upon these, as well as our earlier findings, we propose that exogenous cholesterol through its specific receptor regulates cholesterogenesis either directly or by initiating the transmembrane-signalling pathway involving cyclic nucleotides.
在没有二价离子的情况下，将凝胶过滤的人血小板与胆固醇一起孵育，结果显示外源性胆固醇能够以剂量依赖的方式下调胆固醇生物合成，并且这种现象伴随着磷脂酶D活性的增加。然而，在存在胆固醇或磷脂酸的情况下，外源性钙能够以剂量依赖的方式上调血小板胆固醇合成。此外，环核苷酸（cAMP、cGMP）也有能力直接影响血小板胆固醇合成的调节。基于这些以及我们早期的发现，我们提出外源性胆固醇通过其特定受体直接或通过启动涉及环核苷酸的跨膜信号通路来调节胆固醇生成。
