Power output is increased after phosphorylation of myofibrillar proteins in rat skinned cardiac myocytes
Power output is increased after phosphorylation of myofibrillar proteins in rat skinned cardiac myocytes
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DOI：
10.1161/hh2401.101908
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发表时间：
2001-12-07
影响因子：
20.1
通讯作者：
McDonald, KS
中科院分区：
文献类型：
--
作者：
Herron, TJ;Korte, FS;McDonald, KS
由于蛋白激酶A(PKA)诱导的几种心肌细胞蛋白的磷酸化，β-肾上腺素能刺激增加了哺乳动物心脏的每搏量。这项研究调查了PKA诱导的肌原纤维蛋白的磷酸化是否直接影响心肌细胞的收缩能力。为了测试这种可能性，我们比较了用PKA催化亚单位治疗前后皮肤大鼠心肌细胞的等长力、负荷缩短速度和功率输出。与以前的研究一致，PKA增加了肌球蛋白结合蛋白C和肌钙蛋白I的磷酸化水平，并降低了肌力对钙的敏感性。PKA组两组最大用力分别为25.4±-8.3和31.6+/-11.3mun，差异有统计学意义(P
beta -Adrenergic stimulation increases stroke volume in mammalian hearts as a result of protein kinase A (PKA)-induced phosphorylation of several myocyte proteins. This study investigated whether PKA-induced phosphorylation of myofibrillar proteins directly affects myocyte contractility. To test this possibility, we compared isometric force, loaded shortening velocity, and power output in skinned rat cardiac myocytes before and after treatment with the catalytic subunit of PKA. Consistent with previous studies, PKA increased phosphorylation levels of myosin binding protein C and troponin I, and reduced Ca2+ sensitivity of force. PKA also significantly increased both maximal force (25.4 +/-8.3 versus 31.6 +/- 11.3 muN [P