Lokeshwar V B, Bourguignon L Y
Department of Cell Biology and Anatomy, University of Miami Medical School, Fl. 33101.
Cell Biol Int Rep. 1992 Sep;16(9):883-97. doi: 10.1016/s0309-1651(06)80168-2.
In this study we have used several complementary biochemical and immunological techniques to examine the involvement of Ca2+ and myosin light chain kinase in collagen-induced platelet activation. Our results indicate that collagen stimulates a rapid influx of external Ca2+ (within the first 1-5 min of treatment) which is followed by phosphorylation of myosin light chains (within 10 min of treatment) and granule secretion (within 15 min of treatment). In addition, we have found that certain Ca2+ channel entry blockers (e.g. nifedipine and bepridil) or calmodulin antagonists (e.g. W-7) specifically inhibit collagen-induced Ca2+ influx, myosin light chain phosphorylation and subsequent granule secretion. These data suggest that Ca2+/calmodulin-dependent myosin light chain kinase-mediated myosin light chain phosphorylation is necessary for regulating the actomyosin-related contractility required for normal platelet function.
在本研究中，我们使用了多种互补的生化和免疫技术来检测钙离子（Ca2+）和肌球蛋白轻链激酶在胶原诱导的血小板激活过程中的作用。我们的结果表明，胶原刺激细胞外Ca2+快速内流（在处理后的最初1 - 5分钟内），随后是肌球蛋白轻链的磷酸化（在处理后10分钟内）和颗粒分泌（在处理后15分钟内）。此外，我们发现某些Ca2+通道进入阻滞剂（如硝苯地平和苄普地尔）或钙调蛋白拮抗剂（如W - 7）能特异性抑制胶原诱导的Ca2+内流、肌球蛋白轻链磷酸化及随后的颗粒分泌。这些数据表明，Ca2+/钙调蛋白依赖性肌球蛋白轻链激酶介导的肌球蛋白轻链磷酸化对于调节正常血小板功能所需的肌动球蛋白相关收缩性是必要的。
