Roch-Norlund A E, Horn R S, Gautvik K M, Walaas E, Walaas O
Horm Metab Res. 1978 May;10(3):208-13. doi: 10.1055/s-0028-1093436.
Cyclic AMP dependent protein kinase has beeen identified in human skeletal muscle tissue. In crude muscle extracts the enzyme was 3--5 fold activated by cyclic AMP. The cyclic AMP-dependent activity (corresponding to the inactive holoenzyme) was completely inhibited by the heat stable inhibitor of protein kinase. Reciprocal changes of the cyclic AMP-dependent activity in skeletal muscle were observed after administration of epinephrine and insulin in vivo. Infusion of epinephrine in healthy volunteers increased the level of cyclic AMP and decreased the activity of the cyclic AMP-depenent form (i.e. the inactive form) of protein kinase. These changes were reversible after cessation of epinephrine administration. The results are consistent with an activation of protein kinase in vivo due to an epinephrine mediated increase of the concentration of cyclic AMP. I.v. injection of insulin had the opposite effect on the enzyme in skeletal muscle, leading to increased activity of the cyclic AMP-dependent form of protein kinase. Insulin had no effect on the level of cyclic AMP, but promoted a transient increase of cyclic GMP 1 min. after insulin injection. The effect by insulin on protein kinase cannot be related to the level of cyclic AMP or cyclic GMP.
环磷酸腺苷（cAMP）依赖性蛋白激酶已在人体骨骼肌组织中被鉴定出来。在粗制肌肉提取物中，该酶被环磷酸腺苷激活了3至5倍。蛋白激酶的热稳定抑制剂完全抑制了环磷酸腺苷依赖性活性（对应于无活性的全酶）。在体内给予肾上腺素和胰岛素后，观察到骨骼肌中环磷酸腺苷依赖性活性的相互变化。向健康志愿者输注肾上腺素会增加环磷酸腺苷水平，并降低蛋白激酶的环磷酸腺苷依赖性形式（即无活性形式）的活性。停止给予肾上腺素后，这些变化是可逆的。结果与肾上腺素介导的环磷酸腺苷浓度增加导致体内蛋白激酶活化一致。静脉注射胰岛素对骨骼肌中的该酶有相反的作用，导致蛋白激酶的环磷酸腺苷依赖性形式的活性增加。胰岛素对环磷酸腺苷水平没有影响，但在注射胰岛素1分钟后促进了环磷酸鸟苷（cGMP）的短暂增加。胰岛素对蛋白激酶的作用与环磷酸腺苷或环磷酸鸟苷的水平无关。
