Inhibition of smooth muscle tension by cyclic AMP-dependent protein kinase
Inhibition of smooth muscle tension by cyclic AMP-dependent protein kinase
复制标题
环 AMP 依赖性蛋白激酶抑制平滑肌张力
作者：
W. Kerrick;W. Kerrick;P. E. Hoar
儿茶酚胺对平滑肌的β-肾上腺素能松弛与环AMP 1，2水平升高相关。问题是，环腺苷酸依赖性蛋白激酶3，4的后续激活是否在平滑肌收缩的调节中起作用。有大量证据表明，Ca 2+激活的肌球蛋白轻链激酶/磷酸酶系统调节平滑肌收缩5 -15，Adelstein等人16，17已经表明，环AMP依赖性蛋白激酶的催化亚基3，4通过轻链激酶的高分子量亚基的磷酸化在该调节中起作用，这导致激酶活性降低。在这里，我们首次表明，蛋白激酶的催化亚基抑制皮肤平滑肌纤维制剂中的Ca 2+激活的张力。
β-adrenergic relaxation of smooth muscle by catecholamines has been associated with elevated levels of cyclic AMP1,2. The question arises whether subsequent activation of cyclic AMP-dependent protein kinase3,4 has a role in the regulation of smooth muscle contraction. There is substantial evidence that a Ca2+-activated myosin light chain kinase/phosphatase system regulates smooth muscle contraction5–15, and Adelstein et al.16,17 have shown that the catalytic subunit of cyclic AMP-dependent protein kinase3,4 plays a part in this regulation, by phosphorylation of the high molecular weight subunit of the light chain kinase, which results in a decrease in the activity of the kinase. Here we have shown for the first time that the catalytic subunit of the protein kinase inhibits Ca2+-activated tension in skinned smooth muscle fibre preparations.