Vaitukaitis J L, Lee C Y, Ebersole E R, Lerario A C
Endocrinology. 1975 Jul;97(1):215-22. doi: 10.1210/endo-97-1-215.
The present experiments were designed to study whether exogenous hCG could elicit acute changes in the ovarian concentration of soluble cAMP-dependent protein kinases temporally related to binding of hCG and intracellular accumulation of cAMP. Cyclic AMP dependent protein kinase activity decreased five-fold within 5 to 30 min after intravenous administration of highly purified hCG to pseudopregnant rats. Moreover cAMP dependent protein kinase activity was totally suppressed with 0.5 IU hCG, whereas tissue concentration of cAMP continued to increase throughout the dose range (0.05-5.0 IU) of hCG used in the present studies. A marked fall in cAMP-dependent protein kinase activity had occurred before there was a significant change in intracellular accumulation of cAMP, possibly reflecting intracellular compartmentalization of cAMP. Inhibitors of protein did not affect the hCG-induced changes in tissue concentrations of cAMP and soluble cAMP dependent protein kinase activity but did suppress the recovery of cAMP dependent protein kinase activity to pretreatment levels. Cyclic AMP dependent protein kinases appear to play a significant role in mediating hormonal action in vivo. In addition the present studies suggest that, protein kinases may protect the cell from excessive hormonal stimulation.
本实验旨在研究外源性人绒毛膜促性腺激素（hCG）是否能引起卵巢中可溶性环磷酸腺苷（cAMP）依赖性蛋白激酶浓度的急性变化，这些变化与hCG的结合以及cAMP在细胞内的积累在时间上相关。向假孕大鼠静脉注射高度纯化的hCG后，在5至30分钟内，cAMP依赖性蛋白激酶活性下降了五倍。此外，0.5国际单位的hCG可完全抑制cAMP依赖性蛋白激酶活性，而在本研究中使用的hCG整个剂量范围（0.05 - 5.0国际单位）内，cAMP的组织浓度持续增加。在细胞内cAMP积累出现显著变化之前，cAMP依赖性蛋白激酶活性就已明显下降，这可能反映了cAMP的细胞内区室化。蛋白质抑制剂并不影响hCG诱导的cAMP组织浓度变化以及可溶性cAMP依赖性蛋白激酶活性，但确实抑制了cAMP依赖性蛋白激酶活性恢复到预处理水平。cAMP依赖性蛋白激酶似乎在介导体内激素作用中发挥重要作用。此外，本研究表明，蛋白激酶可能保护细胞免受过度的激素刺激。
