{"title":"Insulin action on cardiac glucose transport. Studies on the role of the sodium pump.","authors":"J Eckel, H Reinauer","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Isolated muscle cells from adult rat heart have been used to study the relationship between myocardial glucose transport and the activity of the Na+, K+ pump. 86Rb+ uptake by cardiac cells was found to be linear up to 2 min, with a steady state reached by 40-60 min, and was used to monitor the activity of the sodium pump. Both the ouabain-sensitive and ouabain-insensitive 86Rb+ uptake by cardiac cells were found to be unaffected by insulin treatment under conditions in which a significant stimulation of 3-O-methylglucose transport occurred. 86Rb+ uptake was markedly reduced by the presence of calcium or magnesium or both, but remained unresponsive toward insulin treatment. Inhibition of the sodium-pump activity by ouabain and a concomitant shift in the intracellular Na+/K+ ratio did not affect basal or insulin-stimulated rates of 3-O-methylglucose transport in cardiac myocytes. The data argue against a functional relationship between the myocardial Na+, K+ pump and the glucose-transport system.</p>","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in myocardiology","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Isolated muscle cells from adult rat heart have been used to study the relationship between myocardial glucose transport and the activity of the Na+, K+ pump. 86Rb+ uptake by cardiac cells was found to be linear up to 2 min, with a steady state reached by 40-60 min, and was used to monitor the activity of the sodium pump. Both the ouabain-sensitive and ouabain-insensitive 86Rb+ uptake by cardiac cells were found to be unaffected by insulin treatment under conditions in which a significant stimulation of 3-O-methylglucose transport occurred. 86Rb+ uptake was markedly reduced by the presence of calcium or magnesium or both, but remained unresponsive toward insulin treatment. Inhibition of the sodium-pump activity by ouabain and a concomitant shift in the intracellular Na+/K+ ratio did not affect basal or insulin-stimulated rates of 3-O-methylglucose transport in cardiac myocytes. The data argue against a functional relationship between the myocardial Na+, K+ pump and the glucose-transport system.
用离体大鼠心肌细胞研究了心肌葡萄糖转运与Na+, K+泵活性的关系。心脏细胞对86Rb+的摄取在2分钟内呈线性,在40-60分钟内达到稳定状态,并用于监测钠泵的活性。研究发现,在显著刺激3- o -甲基葡萄糖转运的情况下,心肌细胞对瓦阿因敏感和瓦阿因不敏感的86Rb+摄取不受胰岛素治疗的影响。86Rb+摄取因钙或镁或两者同时存在而明显减少,但对胰岛素治疗仍无反应。瓦巴因对钠泵活性的抑制和细胞内Na+/K+比值的变化并不影响心肌细胞中基础或胰岛素刺激的3- o -甲基葡萄糖运输速率。这些数据反对心肌Na+, K+泵与葡萄糖转运系统之间的功能关系。