[Experimental dilatation of the cecum and colon in rats. II. Reversion after induction by the continuous administration of lactose].

Fifty female Wistar weanling rats were fed a laboratory diet containing lactose (25 g/100 g of the final mixture) during 28 days. Following this period the lactose was substituted isocalorically by saccharose (25 g/100 g of the final mixture) and the diet given to the animals for 21 days. Thirty control rats of the same sex and weight received a laboratory diet containing saccharose (25 g/100 g of diet) during 49 days. The animals were weighed weekly. Subgroups of experimental and control rats were sacrificed at days 28, 30, 32, 35, 42 and 49. Rats given a diet containing lactose showed restriction of body weight gain. Upon rehabilitation the body weight of these animals increased rapidly. The external volume of the cecum and colon showed a significant increase during the 28-day period. After nutritional rehabilitation this change reduced gradually, beginning in the first week. Although the weight of the cecum reduced gradually during the rehabilitation period, the values were slightly augmented at day 49 as compared to controls. In conclusion, in the conditions of the present study, the consequences on the cecum and colon of adding lactose to the diet of rats are not persistent.