EFFECTS OF CHRONIC ALCOHOL-CONSUMPTION ON ENZYME-ACTIVITIES AND ACTIVE METHIONINE ABSORPTION IN THE SMALL-INTESTINE OF PREGNANT RATS

The present study evaluates the effect of chronic alcohol intake on th e intestinal transport of methionine during pregnancy. For this purpos e, we have used an in vitro technique that allows measurement of the u nidirectional influx of the amino acids across the brush-border membra ne of the rat mid-jejunum, and the basolateral membrane enzyme Na+,K+- ATPase was also evaluated in the duodenum and jejunum. For chronic alc ohol treatment, the rats were fed a liquid diet containing ethanol (36 % of calories) or an isocaloric diet (pair-fed control) for 5 weeks be fore and during pregnancy. Animals were killed at 21 days of gestation . Results from the kinetic analysis revealed that chronic ethanol trea tment reduces the maximum transport (J(m)) of methionine uptake when c ompared with controls. Further experiments performed in the presence a nd absence of sodium have shown that ethanol selectively inhibited Na-dependent methionine transport. At the same time, this treatment sign ificantly reduced the levels of Na+,K+-ATPase in ethanol-fed rats comp ared with the controls. Alterations in methionine intestinal transport in pregnant alcohol-fed rats may contribute to the ethanol-induced fe tal growth abnormalities.