Molecular biology mark study on development of digestive and absorptive function of mothr's milk fed rat pups intestine : Developmental changes in protein -Effect of neonatal undernutrition on the subsquent development of protein digestive and absorptive

我们研究了新生儿营养不良对大鼠肠道蛋白质消化吸收功能的影响。对照组8只幼犬一窝饲养，营养不良组16只幼犬从2岁开始饲养1周，然后8只幼犬一窝饲养。分别于对照组和营养不良幼崽第2、9、16和23天测定其肠腔蛋白质消化功能（蛋白水解活性）、利用外翻小肠囊吸收蛋白质功能（胞饮活性）以及肠黏膜和肝脏组织蛋白酶B活性。对照组蛋白水解活性分别为7.6177.3530.6 （μ g/tripsin当量/ml）。与对照组相比，营养不良组的数值有所下降（分别为70.3、46.8和98.5%）。营养不良组在第9、16天的黏膜摄取量显著增加（分别是对照组的5.6、1.9倍），但在第23天的黏膜摄取量与对照组无显著差异。另一方面，RI标记的BLG比各相反对照增加更多（69.6倍，2.3倍，3.4倍）。对照组肝脏在第9、16、23天的组织蛋白酶B活性（U/mg蛋白/ml）分别为10.4、18.1、9.7。营养不良组的活动量在这几天显著下降（7.9,10.0,7.1）。肠黏膜组在第9、16天（4.4、4.3）显著低于对照组，在第23天显著升高（2倍于对照组）。这些研究表明，新生儿营养不良可能对蛋白质消化和吸收功能的后续发展产生不利影响，并可能是未来过敏性疾病发展的一个因素。

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 control), 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.