饥饿对分离的小鼠胰岛中磷酸二酯酶活性及3',5'-环磷酸腺苷含量的影响。

The effect of starvation on phosphodiesterase activity and the content of adenosine 3' :5'-cyclic monophosphate in isolated mouse pancreatic islets.

作者信息

Capito K, Hedeskov C J

出版信息

Biochem J. 1974 Sep;142(3):653-8. doi: 10.1042/bj1420653.

DOI:10.1042/bj1420653

PMID:4377213

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1168331/

Abstract

The concentration of cyclic AMP and the activity of phosphodiesterase were measured in isolated pancreatic islets from fed or 48h-starved mice. 2. Two different phosphodiesterases were detected. Neither the maximum activity nor the K(m) values of these enzymes were changed by starvation. 3. The concentration of cyclic AMP in non-incubated islets was the same in islets from fed and starved mice. 4. Incubation with 3.3mm-glucose for 5-30min had no effect on the concentration of cyclic AMP, irrespective of the nutritional state of the mice. Incubation with 16.7mm-glucose for 5-30min raised the concentration of cyclic AMP by about 30% in islets from fed mice. This rise was prevented by addition of mannoheptulose (3mg/ml). Incubation with 16.7mm-glucose had no effect on the cyclic AMP content in islets from starved mice. 5. In islets from fed mice 10min incubation with 5mm-caffeine had no effect on the concentration of cyclic AMP in the presence of 3.3 or 16.7mm-glucose, whereas the cyclic AMP content was increased approx. 150% in islets from starved mice. 6. After 10min incubation with 1mm-3-isobutyl-1-methylxanthine in the presence of 3.3 or 16.7mm-glucose the concentration of cyclic AMP was raised by 250% in islets from fed mice and by 400% in islets from starved mice. 7. A threefold function of glucose in the insulin-secretory process is suggested, according to which the decreased islet glucose metabolism is the primary defect in the insulin-secretory mechanism during starvation.

摘要

测定了喂食或饥饿48小时小鼠分离胰岛中环磷酸腺苷（cAMP）的浓度和磷酸二酯酶的活性。2. 检测到两种不同的磷酸二酯酶。饥饿并未改变这些酶的最大活性或米氏常数（K(m)）。3. 未孵育的喂食小鼠和饥饿小鼠胰岛中的cAMP浓度相同。4. 无论小鼠的营养状态如何，在3.3mM葡萄糖中孵育5 - 30分钟对cAMP浓度均无影响。在16.7mM葡萄糖中孵育5 - 30分钟可使喂食小鼠胰岛中的cAMP浓度升高约30%。添加甘露庚酮糖（3mg/ml）可阻止这种升高。在16.7mM葡萄糖中孵育对饥饿小鼠胰岛中的cAMP含量无影响。5. 在喂食小鼠的胰岛中，在3.3或16.7mM葡萄糖存在下，用5mM咖啡因孵育10分钟对cAMP浓度无影响，而饥饿小鼠胰岛中的cAMP含量增加了约150%。6. 在3.3或16.7mM葡萄糖存在下，用1mM 3 - 异丁基 - 1 - 甲基黄嘌呤孵育10分钟后，喂食小鼠胰岛中的cAMP浓度升高了250%，饥饿小鼠胰岛中的cAMP浓度升高了400%。7. 提示葡萄糖在胰岛素分泌过程中具有三重作用，据此，胰岛葡萄糖代谢降低是饥饿期间胰岛素分泌机制的主要缺陷。