Hostmark A T, Gronnerod O, Horn R S
Horm Metab Res. 1976 Mar;8(2):123-8. doi: 10.1055/s-0028-1093666.
The influence of fasting and refeeding on the response to adrenergic stimulation of several enzymes involved in glycogen metabolism has been investigated in the isolated, intact rat diaphragm. The in vitro response of the phosphorylase system to terbutaline was found to decrease markedly following fasting. A pronounced increase in this response was seen upon refeeding. This increased responsiveness was normalized by incubation of isolated tissues with palmitate (1.5 mM). Plasma free fatty acid concentration was increased in fasted rats compared to the value found in refed animals. The effect of terbutaline on cyclic AMP concentration and protein kinase activity was not significantly influenced by fasting and refeeding while fasting decreased the effect of terbutaline upon phosphorylase b kinase. Diaphragm glycogen levels were reduced by more than 50% in rats fasted for 24 hours and were significantly increased upon refeeding compared to fed rats. The results indicate that the nutritional state can modulate the sensitivity of the interconverting system for phosphorylase. It is suggested that this modulation might depend upon fatty acid metabolism.
在离体完整的大鼠膈肌中，研究了禁食和再喂食对参与糖原代谢的几种酶对肾上腺素能刺激反应的影响。发现禁食后磷酸化酶系统对特布他林的体外反应明显降低。再喂食后，这种反应明显增加。用棕榈酸（1.5 mM）孵育分离的组织可使这种增加的反应性恢复正常。与再喂食动物相比，禁食大鼠的血浆游离脂肪酸浓度升高。禁食和再喂食对特布他林对环磷酸腺苷浓度和蛋白激酶活性的影响无显著影响，而禁食降低了特布他林对磷酸化酶b激酶的作用。禁食24小时的大鼠膈肌糖原水平降低了50%以上，与喂食大鼠相比，再喂食后显著增加。结果表明，营养状态可调节磷酸化酶相互转化系统的敏感性。提示这种调节可能取决于脂肪酸代谢。
