Ultrastructural study of mechanism and prevention of the food allergy during suckling to weaning period.

本实验研究了小肠发育过程中的结构变化和小肠吸收细胞对大分子物质的吸收。本研究旨在阐明食物过敏原的侵入途径，建立断奶过程中食物过敏的预防方法。在哺乳期大鼠，小肠吸收细胞从小肠腔中摄取包括抗体在内的母乳大分子物质。此外，在近端小肠的吸收细胞中观察到转胞吞作用。但断奶后小肠的消化吸收系统发生了很大变化。断奶后，小肠吸收细胞吸收消化道和微绒毛上的小分子物质，哺乳期摄食影响小肠吸收细胞的结构和功能，尤其是大分子物质的吸收。摄食7 d后，不同饲料对吸收细胞的结构和功能有不同的影响。母乳喂养与其他食物喂养的大鼠吸收细胞对大分子物质的摄取量有很大差异，提示母乳喂养对预防食物过敏有一定的作用。在母乳无法喂养的情况下，以小分子奶粉喂养为佳。转胞吞途径关闭后，应喂人工奶和其他饲料。提示哺乳-断奶期喂养对预防食物过敏有重要意义。

We investigated that the structure of the small intestine and macromolecular uptake into the absorptive cells during postnatal development. The aim of this study was to elucidate the invasive pathway of food allergen and establish the preventive method of the food allergy during weaning process.In the neonatal-suckling rats, the absorptive cells of the small intestine endocytosed maternal milk macromolecules including antibodies from the lumen. Moreover, transcytosis was observed in the absorptive cells from the proximal small intestine. The digestive and absorptive system of the small intestine, however, greatly changed in the weaned rat. After weaning, the absorptive cells absorbed small molecules that were digested in the alimental canal and on the microvilli.In the neonatal-suckling period, feeding influenced the structure and function, especially macromolecular uptake, of the small intestinal absorptive cells. After 7days feeding, the structure and function of the absorptive cells varied with diet. Macromolecular uptake into the absorptive cells greatly differed between feeding on maternal milk and other diet.These results suggested that feeding on only maternal milk was preferable to prevent the food allergy. In case of impossible to feed on maternal milk, feeding on small molecule was better. After closed the transcytotic pathway, artificial milk and other diet should be fed. It seemed that feeding in the suckling-weaning period was important to prevent the food allergy.