期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1992
卷号：38
期号：4
页码：365-374
DOI：10.3177/jnsv.38.365
出版社：Center for Academic Publications Japan
摘要：The effect of jejunum-bypass operation on lactase in rat small intestine was examined. Three groups of four or five rats were designated as jejunum-bypassed, sham-operated and normal rats. All animals including normal rats received by pair-feeding 5% glucose/l% NaCI for 5 days following the operation; thereafter they were fed ad libitum the laboratory chow diet. Three weeks after the jejunal bypass operation, the proximal ileum exhibited a hypera plasia as evidenced by a concomitant increase in mucosal contents of both total proteins and DNA. The specific activity of lactase in this segment was significantly lower in the operated rats than sham-operated controls, whereas the specific activity of sucrase in this segment was significantly elevated. The reduction of lactase activity was also evident in the proximal jejunal segment as well as in the distal jejunum which was deprived of luminal nutrition, suggesting that some hormonal factor (s) might be involved in the decrease of lactase activity in jejunum-bypassed animals. Electroim-munoassay revealed that the amount of immunoreactive lactase also declined in the operated rats relative to the sham-operated controls. Our results thus suggest that lactase activity in residual ileum is not only unable to compensate for the loss of digestive-absorptive surface of jejunum, but lactase activity even decreases following jejunum-bypass operation.
