Mansbach C M
J Lipid Res. 1983 Oct;24(10):1310-20.
The effect of ethanol infusion on intestinal lipid absorption was studied in rats with a duodenal cannula. Rats were infused with ethanol overnight and ethanol was included in a trioleoylglycerol emulsion infusion given for 3 hr the next day. These rats were compared to control animals infused with glucose (isocalorically). The ethanol-infused rats had a greatly impaired lipid absorptive capacity. The monoacylglycerol and free fatty acid contents in the intestinal lumen in the ethanol-infused rats were 4- and 7-fold greater, respectively, than controls. The inhibition of absorption was not due to an effect of ethanol on lipolytic activity. The lipase content of the ethanol-infused rats was greater than controls and the separate infusion of monoacylglycerol and fatty acids demonstrated impaired absorption of these end products of lipolysis as compared to controls. To observe if these changes were due to an effect of ethanol on the enterocyte brush border membrane, the membrane lipids were analyzed. The phosphatidylcholine, lysophosphatidylcholine, and phosphatidylethanolanine content was reduced but not the neutral lipids, sphingomyelin, or phosphatidylserine. The uptake of fatty acid into intestinal rings was also shown to be impaired by ethanol infusion. Lastly, the specific activity of the neutral lipids remaining in the intestinal lumen after [3H]glycerol-labeled trioleoylglycerol-infusion was similar to controls even though the mass was much greater. It is concluded that ethanol impairs neutral lipid absorption due to an effect on the enterocyte brush border membrane and by increasing the efflux of low specific activity lipid from the enterocyte back out into the intestinal lumen. A potential pathway for this efflux is the recently described increased porosity of the apical junctional complex in response to ethanol infusion.
在具有十二指肠插管的大鼠中研究了乙醇输注对肠道脂质吸收的影响。大鼠过夜输注乙醇，次日给予含乙醇的三油酰甘油乳剂输注3小时。将这些大鼠与输注葡萄糖（等热量）的对照动物进行比较。输注乙醇的大鼠脂质吸收能力大大受损。输注乙醇的大鼠肠腔内单酰甘油和游离脂肪酸含量分别比对照组高4倍和7倍。吸收抑制并非由于乙醇对脂解活性的影响。输注乙醇的大鼠脂肪酶含量高于对照组，与对照组相比，单独输注单酰甘油和脂肪酸显示这些脂解终产物的吸收受损。为了观察这些变化是否是由于乙醇对肠上皮细胞刷状缘膜的影响，对膜脂质进行了分析。磷脂酰胆碱、溶血磷脂酰胆碱和磷脂酰乙醇胺含量降低，但中性脂质、鞘磷脂或磷脂酰丝氨酸含量未降低。乙醇输注也显示脂肪酸进入肠环的摄取受损。最后，在输注[3H]甘油标记的三油酰甘油后，肠腔内剩余中性脂质的比活性与对照组相似，尽管质量要大得多。得出的结论是，乙醇损害中性脂质吸收是由于对肠上皮细胞刷状缘膜的影响以及增加了低比活性脂质从肠上皮细胞回流到肠腔的流出。这种流出的一个潜在途径是最近描述的响应乙醇输注而增加的顶端连接复合体的孔隙率。
