Dinda P K, Beck I T
Dig Dis Sci. 1981 Jan;26(1):23-32. doi: 10.1007/BF01307972.
Acute exposure of jejunal mucosa to ethanol has been reported to produce a depression of transmural glucose transport across this organ in vitro and in vivo. In an attempt to understand the mechanism of action of ethanol on intestinal transport, in the present study we have investigated the effect of ethanol on glucose uptake by purified brush-border membrane vesicles of hamster jejunum. Ethanol, in concentrations found in man after moderate drinking (1-5% w/v), was found to depress glucose uptake by the brush-border membrane in a dose-dependent and time-dependent manner. Mannose was used to measure nonspecific uptake, and we found that the ethanol-induced depression of glucose uptake was not related to an alteration of the nonspecific uptake of this sugar. The inhibition of glucose uptake of the ethanol-treated membranes completely disappeared after repeated washing of the membranes with ethanol-free buffer. Accordingly, the ethanol-induced depression of glucose uptake was not the result of irreversible damage to membrane proteins but was related to a direct effect of ethanol on the brush-border membrane. On the basis of these findings, it is concluded that a direct interference with glucose translocation across the brush border plays an important role in the ethanol-induced depression of transmural jejunal glucose absorption.
据报道，空肠黏膜急性暴露于乙醇会导致在体外和体内跨该器官的透壁葡萄糖转运降低。为了了解乙醇对肠道转运的作用机制，在本研究中，我们研究了乙醇对仓鼠空肠纯化刷状缘膜囊泡摄取葡萄糖的影响。发现，在适度饮酒后人体中存在的浓度（1-5% w/v）的乙醇，会以剂量依赖性和时间依赖性方式抑制刷状缘膜摄取葡萄糖。用甘露糖来测量非特异性摄取，我们发现乙醇诱导的葡萄糖摄取降低与该糖的非特异性摄取改变无关。用无乙醇缓冲液反复洗涤膜后，乙醇处理的膜对葡萄糖摄取的抑制作用完全消失。因此，乙醇诱导的葡萄糖摄取降低不是膜蛋白不可逆损伤的结果，而是与乙醇对刷状缘膜的直接作用有关。基于这些发现，得出结论：乙醇对跨刷状缘葡萄糖转运的直接干扰在乙醇诱导的空肠透壁葡萄糖吸收降低中起重要作用。
