Levin P A, Bistritzer T, Hanukoglu L, Max S R, Roeder L M
Department of Pediatrics, University of Maryland School of Medicine, Baltimore.
Horm Metab Res. 1990 Dec;22(12):608-11. doi: 10.1055/s-2007-1004984.
3H-2-deoxyglucose (2-DG) uptake was measured in L6A-1 rat skeletal muscle cells (a rapidly fusing subclone of L6), following addition of several concentrations (10(-16) to 10(-9)M) of the N-terminal fragment of ACTH1-24 to cells deprived of serum and insulin for 21 hours, but maintained in the presence of (5 micrograms/ml) insulin (stimulated state). There was a marked dose-dependent increase of 2-DG uptake at the various ACTH1-24 (P less than 0.001). There was no correlation between the time of exposure of the cells to serum-free conditions and the rate of uptake of 2-DG at the various ACTH1-24 concentrations both in the basal and insulin-stimulated states. Addition of catochalasin B (50 microM) to the cells, which inhibited both basal and insulin-stimulated uptake of 2-DG (by 70% and 91%, respectively) completely eliminated the enhancement of both of these uptake rates to 10(-12)M ACTH1-24. The results suggest that: 1) ACTH1-24 stimulates carrier-mediated uptake of glucose in skeletal muscle cells. 2) The site of action of ACTH1-24 is on the non-insulin mediated glucose uptake (NIMGU) system. 3) ACTH1-24 may be a useful probe to delineate some of the events associated with the NIMGU pathway.
在L6A - 1大鼠骨骼肌细胞（L6的一个快速融合亚克隆）中测量3H - 2 - 脱氧葡萄糖（2 - DG）摄取，这些细胞在无血清和胰岛素的条件下培养21小时，但在（5微克/毫升）胰岛素存在下维持（刺激状态），之后加入几种浓度（10^(-16)至10^(-9)M）的促肾上腺皮质激素1 - 24的N端片段。在不同浓度的促肾上腺皮质激素1 - 24作用下，2 - DG摄取呈现出显著的剂量依赖性增加（P < 0.001）。在基础状态和胰岛素刺激状态下，细胞暴露于无血清条件的时间与不同浓度促肾上腺皮质激素1 - 24作用下的2 - DG摄取速率之间均无相关性。向细胞中添加卡托查拉辛B（50微摩尔），其抑制基础状态和胰岛素刺激状态下的2 - DG摄取（分别抑制70%和91%），完全消除了这两种摄取速率对10^(-12)M促肾上腺皮质激素1 - 24的增强作用。结果表明：1）促肾上腺皮质激素1 - 24刺激骨骼肌细胞中载体介导的葡萄糖摄取。2）促肾上腺皮质激素1 - 24的作用位点在非胰岛素介导的葡萄糖摄取（NIMGU）系统上。3）促肾上腺皮质激素1 - 24可能是描绘与NIMGU途径相关的一些事件的有用探针。
