Sonoyama K, Kiriyama S, Niki R
Laboratory of Food Biochemistry, Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
J Nutr Sci Vitaminol (Tokyo). 1993 Dec;39(6):617-25. doi: 10.3177/jnsv.39.617.
To examine the effect of bile acids on the activity of intestinal aminopeptidase in vivo, we measured the activity of aminopeptidase in the intestinal mucosa from rats fed the diet containing cholestyramine which sequesters luminal bile acids (experiment 1) and from bile diverted rats (experiment 2). After 32 h fasting, rats were refed for 16 h either of a standard diet (25% casein diets), the same diet containing cholestyramine, or the fat-free diet in experiment 1. In the intestinal washing, the content of total bile acids was markedly decreased with feeding cholestyramine and activities of trypsin and chymotrypsin were also lowered with cholestyramine. Cholestyramine feeding decreased the specific activity of aminopeptidase in the homogenate of intestinal mucosa but increased the specific activities of sucrase and alkaline phosphatase. All these parameters were not modified by the fat-free diet. In experiment 2, bile diverted and sham operated rats were refed the standard diet for 16 h with prior 32 h fasting. Bile diversion, like cholestyramine feeding, lowered the content of total bile acids, the activities of pancreatic hydrolases in the intestinal washings, and the specific activity of aminopeptidase in the intestinal mucosa. The specific activity of sucrase in the intestinal mucosa was higher in bile diverted rats but the activity of alkaline phosphatase was not changed. These data indicate that the decreased abundance of intraluminal bile acid affects the activity of intestinal aminopeptidase not through the decreased absorption of dietary lipid.(ABSTRACT TRUNCATED AT 250 WORDS)
为了研究胆汁酸对体内肠氨肽酶活性的影响，我们测量了喂食含消胆胺（可螯合肠腔胆汁酸）的饮食的大鼠（实验1）以及胆汁引流大鼠（实验2）肠黏膜中氨肽酶的活性。禁食32小时后，在实验1中，大鼠重新喂食标准饮食（25%酪蛋白饮食）、含消胆胺的相同饮食或无脂饮食16小时。在肠洗液中，喂食消胆胺后总胆汁酸含量显著降低，胰蛋白酶和糜蛋白酶的活性也因消胆胺而降低。喂食消胆胺会降低肠黏膜匀浆中氨肽酶的比活性，但会增加蔗糖酶和碱性磷酸酶的比活性。所有这些参数均未因无脂饮食而改变。在实验2中，胆汁引流和假手术大鼠在禁食32小时后重新喂食标准饮食16小时。胆汁引流与喂食消胆胺一样，会降低总胆汁酸含量、肠洗液中胰腺水解酶的活性以及肠黏膜中氨肽酶的比活性。胆汁引流大鼠肠黏膜中蔗糖酶的比活性较高，但碱性磷酸酶的活性未改变。这些数据表明，肠腔内胆汁酸丰度的降低并非通过饮食脂质吸收减少来影响肠氨肽酶的活性。（摘要截短至250字）
