Ip M M, Ip C, Tepperman H M, Tepperman J
J Nutr. 1977 May;107(5):746-57. doi: 10.1093/jn/107.5.746.
Diurnal changes in insulin, glucagon and the cyclic nucleotide-protein kinase system were examined in rats trained to eat a 2-hour daily meal and in control rats fed ad libitum. Sharp increases in both insulin and glucagon were observed in response to feeding in trained rats. However, throughout most of the rest of the day, the plasma concentrations of both hormones were lower in meal-fed than in control rats. In adipose tissue, diurnal changes in cyclic AMP concentration were inversely correlated with changes in plasma insulin concentration. In general, cyclic AMP concentrations were depressed and cyclic GMP elevated in adipose tissue of meal-fed rats compared with those fed ad libitum. Diurnal changes in cyclic GMP concentration tended to parallel those of cyclic AMP. Cyclic AMP-activated protein kinase was elevated in adipose tissue of meal-fed rats. However, with the exception of fasting rats, the percentage of the enzyme in the active form was decreased. In liver, there was no clear relation significant differenced were observed with the protein kinase. It can be concluded that the magnitude of the adaptive response of the cyclic nucleotide-protein kinase system to meal-feeding in rats is greater in adipose tissue than in liver.
对经训练每日进食2小时的大鼠以及自由进食的对照大鼠的胰岛素、胰高血糖素和环核苷酸 - 蛋白激酶系统的昼夜变化进行了研究。在经训练的大鼠进食时，观察到胰岛素和胰高血糖素均急剧增加。然而，在一天中的大部分其余时间里，进食餐食的大鼠体内这两种激素的血浆浓度均低于对照大鼠。在脂肪组织中，环磷酸腺苷（cAMP）浓度的昼夜变化与血浆胰岛素浓度的变化呈负相关。一般来说，与自由进食的大鼠相比，进食餐食的大鼠脂肪组织中的cAMP浓度降低，环磷酸鸟苷（cGMP）升高。cGMP浓度的昼夜变化倾向于与cAMP的变化平行。进食餐食的大鼠脂肪组织中环磷酸腺苷激活的蛋白激酶升高。然而，除了禁食大鼠外，处于活性形式的该酶的百分比降低。在肝脏中，与蛋白激酶没有明显的显著差异关系。可以得出结论，大鼠脂肪组织中环核苷酸 - 蛋白激酶系统对进食餐食的适应性反应程度大于肝脏。
