Effect of Carbohydrate and Corticosteroids on Activity of a-Glucosidases in Intestine of the Infant Rat

isomaltase are not detectable in rats before 15-16 days of age, but administration of corticosteroids precociously induces the activities of these two a-glucosidases. 9-day old rats were removed from their mothers, warmed in an incubator, and fed by constant infusion through gastros-tomies. The basic diet was a soya preparation to which various sugars were added. When the diet contained 2% sucrose, diarrhea ensued for 48 hr, but subsided when intestinal sucrase and isomaltase appeared precociously. In animals fed sucrose, the activities of sucrase and iso-maltase were markedly increased as compared to animals on carbohydrate-free diets (sucrase 2.41±0.23 vs. 0.63± 0.13 U, isomaltase 3.43±0.42 vs. 0.78+0.18 U). Maltase activity was doubled, while lactase was not altered signifi-cantly. The mitotic index of crypt cells, the depth of crypts, and incorporation of thymidine-3H into DNA were increased. In adrenalectomized rats, activities of sucrase and isomaltase were not detected nor induced by sucrose. Steroids given to adrenalectomized rats caused appearance of the enzymes; but if cortisone and sucrose were given together, there was synergism evidenced by a marked increase in activities (sucrase 7.2 ± 1.1 vs. 0.68±0.12 U). In contrast to observations in adult ani-mals, the effect of sucrose on a-glucosidases in develop-ing animals demands the participation-of the adrenal gland