Fischer Y, Rose H, Kammermeier H
Institute of Physiology, Medical Faculty, RWTH Aachen, F.R.G.
Life Sci. 1991;49(23):1679-88. doi: 10.1016/0024-3205(91)90310-8.
Freshly isolated adipocytes or cardiac myocytes appear to be subject to unspecific stimulation during isolation and subsequent handling, e.g. with respect to glucose transport. We have developed a modified procedure that yields rat cardiomyocytes with a very low basal, i.e. non stimulated hexose uptake rate (ca. 3 pmol * s-1 * mg protein-1 at 1 mM sugar), as compared to data reported by others. This low value correlates with the reported oxygen consumption of non-beating, isolated rat hearts, when these are perfused with glucose as the only substrate. The basal rate of glucose uptake in our quiescent cardiomyocytes is slightly lower than the value measured by others in beating rat hearts in vivo. Insulin (10 nM) stimulates 2-deoxy-D-glucose uptake 8- to 20-fold and 3-O-methyl-D-glucose uptake 14- to 20-fold, as compared to control. This insulin effect is markedly larger than that usually observed in isolated cardiomyocytes, but it is similar in magnitude to the stimulation of glucose transport reported for isolated, perfused rat hearts. In these cells, new stimulatory effects on the glucose transport, e.g. that of sulfhydryl reagents like phenylarsine oxide, become apparent. We conclude that the cardiomyocytes obtained by this modified method exhibit a basal glucose transport rate that is close to physiological values. These cells represent a new highly responsive model to detect and to investigate the effects of glucose transport stimulators (insulin, contraction etc.).
刚分离出的脂肪细胞或心肌细胞在分离及后续处理过程中似乎会受到非特异性刺激，例如在葡萄糖转运方面。我们开发了一种改进方法，与其他研究报告的数据相比，该方法所获得的大鼠心肌细胞基础（即非刺激状态下）己糖摄取率非常低（在1 mM糖浓度下约为3 pmol·s⁻¹·mg蛋白⁻¹）。这一低值与已报道的以葡萄糖作为唯一底物灌注的非搏动性分离大鼠心脏的耗氧量相关。我们的静态心肌细胞中葡萄糖摄取的基础速率略低于其他研究人员在体内搏动的大鼠心脏中测得的值。与对照组相比，胰岛素（10 nM）可刺激2-脱氧-D-葡萄糖摄取增加8至20倍，3-O-甲基-D-葡萄糖摄取增加14至20倍。这种胰岛素效应明显大于在分离的心肌细胞中通常观察到的效应，但在幅度上与报道的分离的灌注大鼠心脏中葡萄糖转运的刺激效应相似。在这些细胞中，对葡萄糖转运的新刺激效应，例如苯胂氧化物等巯基试剂的刺激效应变得明显。我们得出结论，通过这种改进方法获得的心肌细胞表现出接近生理值的基础葡萄糖转运速率。这些细胞代表了一种新的高反应性模型，可用于检测和研究葡萄糖转运刺激剂（胰岛素、收缩等）的作用。
