Le Huerou I, Guilloteau P, Wicker C, Mouats A, Chayvialle J A, Bernard C, Burton J, Toullec R, Puigserver A
Institut National de la Recherche Agronomique, Rennes, France.
Dig Dis Sci. 1992 Jan;37(1):40-6. doi: 10.1007/BF01308340.
Ten groups of calves were used to study the changes in activity levels and distribution of seven hydrolases in the intestinal mucosa during development and weaning. The calves in the first group were sacrificed at birth while those in the remaining nine groups were either milk-fed until slaughter on days 2, 7, 28, 56, 70, and 119; or weaned between days 28 and 56 and then slaughtered on days 56, 70, and 119, respectively. The small intestine was immediately cut off and divided into five segments, ie, duodenum, proximal jejunum, median jejunum, distal jejunum, and ileum. In the milk-fed animals, the activity levels of aminopeptidases A and N, alkaline phosphatase, lactase, and isomaltase were maximum at 2 days of age, and then declined sharply between days 2 and 7 but did not change significantly thereafter. By contrast, the maltase activity increased between days 7 and 119, while no sucrase activity was detected. Weaning resulted in a decrease in the activity of lactase and an increase in that of aminopeptidase N, maltase, and isomaltase. The distribution of all these enzymes along the small intestine was slightly influenced by age but not at all by weaning.
十组小牛被用于研究发育和断奶期间肠道黏膜中七种水解酶的活性水平变化及分布情况。第一组小牛在出生时被宰杀，其余九组小牛要么一直喂牛奶直至在第2、7、28、56、70和119天宰杀；要么在第28至56天之间断奶，然后分别在第56、70和119天宰杀。小肠被立即切断并分成五段，即十二指肠、空肠近端、空肠中段、空肠远端和回肠。在喂牛奶的动物中，氨肽酶A和N、碱性磷酸酶、乳糖酶和异麦芽糖酶的活性水平在2日龄时最高，然后在第2至7天急剧下降，但此后没有显著变化。相比之下，麦芽糖酶活性在第7至119天增加，而未检测到蔗糖酶活性。断奶导致乳糖酶活性降低，氨肽酶N、麦芽糖酶和异麦芽糖酶活性增加。所有这些酶在小肠中的分布受年龄的影响较小，但完全不受断奶的影响。
