Effects of Chronic Alcohol Consumption on Enzyme Activities and Active Methionine Absorption in the Small Intestine of Pregnant Rats

Abstract

The present study evaluates the effect of chronic alcohol intake on the intestinal transport of methionine during pregnancy. For this purpose, we have used an in vitro technique that allows measurement of the unidirectional influx of the amino acids across the brush-border membrane of the rat mid-jejunum, and the basolateral membrane enzyme Na+, K+-ATPase was also evaluated in the duodenum and jejunum. For chronic alcohol treatment, the rats were fed a liquid diet containing ethanol (36% of calories) or an isocaloric diet-(pair-fed control) for 5 weeks before and during pregnancy. Animals were killed at 21 days of gestation. Results from the kinetic analysis revealed that chronic ethanol treatment reduces the maximum transport (Jm) of methionine uptake when compared with controls. Further experiments performed in the presence and absence of sodium have shown that ethanol selectively inhibited Na+-dependent methionine transport. At the same time, this treatment significantly reduced the levels of Na+, K+-ATPase in ethanol-fed rats compared with the controls. Alterations in methionine intestinal transport in pregnant alcohol-fed rats may contribute to the ethanol-induced fetal growth abnormalities.