We have examined the effect of neonatal undernutrition on protein degestive and absorptive function of rat intestine. Eight pups were reared at a litter in the control group, while 16 pups in the undernourished group were reared for 1 week commencing at the age of 2, and then 8 pups were reared as a litter. Protein digestive function of intestinal lumen (proteolytic activity), the protein absorptive function (pinocytic activity) by using everted small intestinal sac, and the Cathepsin B activity of intestinal mucosa and liver were measured at 2,9,16 and 23 days in control and undernourished pups.
The proteolytic activity was 7.6,177.3,530.6 (mu g/tripsin equivalent/ml) in the control group, respectively. However, the value of undernourished group showed decreases compared with those in the control group (70.3,46.8 and 98.5% of each opposite control). The mucosal uptake amount of RI labeled BSA at 9 and 16 days were increased significantly in the undernourished group (5.6,1.9 times of co
ntrol), but the amount of that at 23 days was not significantly defferent from control. On the other hand, that of RI labeled BLG was more increased compared with each opposite control (69.6,2.3,3.4 times). The Cathepsin B activity (U/mg protein/ml) of the control liver at 9,16,23 days showed 10.4,18.1,9.7. The activity of the undernourished group was significantly declined on these days (7.9,10.0,7.1). While, that of intestinal mucosa groups showed significant decreases compared with those in control group at 9 and 16 days (4.4,4.3), but significant increases (2 times the control value) at 23 days.
These studies suggest that neonatal undernutrition may have unfavorable influences on the subsequent development of protein digestive and absorptive function, and may be a factor in development of future allergic disease.
proteolytic activityは、対照群の推移は日齢9,16,23でそれぞれ7.6,177.3,530.6(μ g/tripsin equivarents/ml)であり、栄養不良群の対照群に対する比[%]はそれぞれ70.3,46.898.5%であり消化管内の蛋白消化能力の一過性の低下を認めたが、日齢23以降は回復がみられた。