Intestinal disaccharidases in newborn and mother rats: effect of dietary protein deficiency during pregnancy

Pups were delivered at term, by cesarean section, from control (CP) and test (TP) rats. The diets fed during pregnancy contained 26% casein (CP rats) or 6% casein (TP rats). At birth, body weight and small intestinal length and weight were significantly lower in pups of TP than in those of CP rats. Specific activity of lactase ( µ moles of lactase hydrolyzed per minute per gram of protein) in the small intestine was similar in the two groups of pups (mean 106 versus 116). However, total activity of lactase in the entire small intestine was significantly lower in the pups of TP than in those of CP rats. In the mothers, the weight of the small intestine in TP rats was almost half that in the CP rats (3.7 versus 7.6 g). The atrophy was noted along the length of the intestine. In the mucosal scrapings of distal third of the small intestine, specific activities of the disaccharidases were significantly greater in TP than in CP rats (lactase, 15.0 versus 6.2; sucrase, 39 versus 21; maltase, 250 versus 152). In the proximal third of the small intestine, only maltase activity was significantly different (lactase, 12.0 versus 10.8; sucrase, 76 versus 61; maltase, 350 versus 258). Total activities of the disaccharidases in the small intestine ( µ moles hydrolyzed per minute, by mucosal scrapings of the entire intestine) were significantly lower in the TP than CP rats (lactase, 4.0 versus 6.4; sucrase, 15 versus 28; maltase, 74 versus 125).