Kelemen S M, Reid H, Gould M K
Diabetes Res Clin Pract. 1986 Apr;2(1):15-22. doi: 10.1016/s0168-8227(86)80024-9.
We have examined the possibility that 125I-insulin binding by isolated rat hepatocytes is modulated by cellular ATP levels. To avoid complications due to ATP-dependent internalization of bound insulin, 125I-insulin binding was determined at 10 degrees C; at this temperature, equilibrium binding was achieved after incubation for 4-6 h. When hepatocytes were incubated at 37 degrees C under anaerobic conditions, ATP levels and 125I-insulin binding were both lowered by about 65%. Anoxia inhibited the association of 125I-insulin with the hepatocyte receptor; the dissociation of insulin from hepatocytes was not affected. Cellular ATP levels and 125I-insulin binding were both restored when anaerobic cells were incubated further at 37 degrees C under aerobic conditions. When anaerobic cells were incubated in air at 10 degrees C during the insulin binding assay, 125I-insulin binding recovered completely, but ATP levels were unaffected. The inhibitory effect of anoxia on 125I-insulin binding was not due to any effect on 125I-insulin degradation or on cell viability. We conclude (1) that the ability of hepatocytes to bind insulin can be modulated on a short-term basis in response to the metabolic status of the cell, and (2) that modulation of the liver cell insulin receptor is not a function of cellular ATP levels.
我们研究了分离的大鼠肝细胞对125I-胰岛素的结合是否受细胞ATP水平调节的可能性。为避免因结合的胰岛素依赖ATP的内化作用而产生复杂情况，在10℃测定125I-胰岛素结合；在此温度下，孵育4-6小时后达到平衡结合。当肝细胞在37℃厌氧条件下孵育时，ATP水平和125I-胰岛素结合均降低约65%。缺氧抑制125I-胰岛素与肝细胞受体的结合；胰岛素从肝细胞的解离不受影响。当厌氧细胞在37℃有氧条件下进一步孵育时，细胞ATP水平和125I-胰岛素结合均恢复。在胰岛素结合测定期间，当厌氧细胞在10℃空气中孵育时，125I-胰岛素结合完全恢复，但ATP水平未受影响。缺氧对125I-胰岛素结合的抑制作用并非由于对125I-胰岛素降解或细胞活力有任何影响。我们得出结论：（1）肝细胞结合胰岛素的能力可根据细胞的代谢状态在短期内受到调节；（2）肝细胞胰岛素受体的调节不是细胞ATP水平的作用。
