Stvolinskaya N, Poljakova E, Nikulina S, Korovkin B
Institute of Biological and Medical Chemistry, Academy of Medical Sciences, Moscow, Russia.
Scand J Clin Lab Invest. 1992 Dec;52(8):791-6. doi: 10.3109/00365519209088382.
The influence of insulin was studied in the monolayer hepatocyte cultures of newborn rats during anoxia. Insulin (1 x 10(-4) U ml-1) caused a significant increase of acid phosphatase activity in the lysosome-rich subcellular fraction after 20 min exposure of the cells to anoxia and also in experiments in which hepatocytes were incubated with insulin for 1 h in normoxia followed by exposure to anoxia for 20 min. The data obtained suggest that insulin had a stabilizing effect on lysosomal membranes when exposure to insulin was prolonged. On the other hand, insulin caused a more-than 2-fold increase in cAMP content in hepatocytes in a 2 min exposition when compared to control cultures. When exposition of the cells to insulin lasted for more than 2 min, lowering of cAMP content was observed. The data seem to indicate that the stabilizing effect of insulin on lysosomal membrane was secondary to the increase in the cAMP level. From the above evidence and that accumulated by others we conclude that there may exist an indirect connection between the cAMP level, insulin stabilizing action, and the state of lysosomal membranes.
在新生大鼠单层肝细胞培养物缺氧期间，研究了胰岛素的影响。在细胞暴露于缺氧环境20分钟后，胰岛素（1×10⁻⁴U/ml⁻¹）使富含溶酶体的亚细胞组分中的酸性磷酸酶活性显著增加；在常氧条件下将肝细胞与胰岛素孵育1小时，然后再暴露于缺氧环境20分钟的实验中，情况也是如此。所获得的数据表明，当延长胰岛素暴露时间时，胰岛素对溶酶体膜具有稳定作用。另一方面，与对照培养物相比，在2分钟的暴露时间内，胰岛素使肝细胞中的环磷酸腺苷（cAMP）含量增加了两倍多。当细胞暴露于胰岛素的时间超过2分钟时，观察到cAMP含量降低。数据似乎表明，胰岛素对溶酶体膜的稳定作用是cAMP水平升高的继发效应。根据上述证据以及其他研究积累的证据，我们得出结论，cAMP水平、胰岛素稳定作用和溶酶体膜状态之间可能存在间接联系。
