Desensitization and muscarinic re-sensitization of force and myosin light chain phosphorylation to cytoplasmic Ca2+ in smooth muscle.
Desensitization and muscarinic re-sensitization of force and myosin light chain phosphorylation to cytoplasmic Ca2+ in smooth muscle.
复制标题
平滑肌细胞质 Ca2 的力脱敏和毒蕈碱再敏化以及肌球蛋白轻链磷酸化。
DOI：
10.1016/0006-291x(90)91589-k
复制
发表时间：
1990
影响因子：
3.1
通讯作者：
Somlyo,AP
中科院分区：
文献类型：
--
作者：
Kitazawa,T;Somlyo,AP
在α-毒素透化的豚鼠回肠平滑肌中，Ca 2+的阶跃增加引起力和肌球蛋白轻链（LC 20）磷酸化的快速上升，随后它们自发下降到较低的稳定水平，即使Ca 2+保持恒定。卡巴胆碱使肌肉对Ca 2+重新敏感，在恒定Ca 2+下引起稳态力和LC 20磷酸化的增加。在β-七叶皂苷透化制剂中，钙调蛋白和冈田酸将对Ca 2+的阶段性反应转化为更具张力的反应。我们的结论是，Ca 2+敏感性的力调制通过改变LC 20激酶/磷酸酶活性比由Ca 2+本身（脱敏）和激动剂（敏化）。
In α-toxin-permeabilized guinea-pig ileum smooth muscle, a step increase in Ca2+caused a rapid rise in force and myosin light chain (LC20) phosphorylation, followed by their spontaneous decline to a low steady level even though Ca2+remained constant. Carbachol resensitized the muscles to Ca2+, causing an increase in both the steady state force and LC20phosphorylation at constant Ca2+. In β-escin permeabilized preparations, calmodulin and okadaic acid converted the phasic responses to Ca2+to more tonic ones. We conclude that Ca2+-sensitivity of force is modulated through changes in LC20kinase/phosphatase activity ratio by Ca2+itself (desensitization) and by agonists (sensitization).