Beynen A C, West C E, Spaaij C J, Huisman J, Van Leeuwen P, Schutte J B, Hackeng W H
Department of Human Nutrition, Agricultural University, Wageningen, The Netherlands.
J Nutr. 1990 May;120(5):422-30. doi: 10.1093/jn/120.5.422.
Swine fitted with re-entrant ileo-cecal cannulas were fed purified diets containing either casein or soybean protein to study possible relations between cholesterol metabolism, digestion of dietary constituents and postprandial patterns of various serum components. Compared with soybean protein, dietary casein produced an increase in serum total cholesterol in which the excess cholesterol was located in the low density lipoprotein fraction. Ileal and fecal excretion of neutral steroids was diminished in pigs fed casein, suggesting that cholesterol absorption was stimulated. The apparent ileal absorption of protein was increased in pigs fed casein. The enhanced absorption of cholesterol and protein was associated with a reduced rate of flow of chyme through the ileum. The output of bile acids in the feces of pigs fed casein was decreased, whereas the ileal output was not significantly affected. This could be attributed to increased uptake of bile acids from the cecum and/or colon, which may in part be related to the indirectly observed decreased formation of secondary bile acids. Postprandial serum concentrations of insulin and glucose were temporarily increased in pigs fed casein, whereas those of triglycerides were decreased. We suggest that the decreased excretion of cholesterol and bile acids is the major determinant of casein-induced hypercholesterolemia in swine.
给安装了回肠 - 盲肠再入式插管的猪喂食含有酪蛋白或大豆蛋白的纯化日粮，以研究胆固醇代谢、膳食成分消化与各种血清成分餐后模式之间的可能关系。与大豆蛋白相比，日粮中的酪蛋白使血清总胆固醇增加，其中过量的胆固醇存在于低密度脂蛋白部分。喂食酪蛋白的猪回肠和粪便中中性类固醇的排泄减少，表明胆固醇吸收受到刺激。喂食酪蛋白的猪蛋白质的表观回肠吸收率增加。胆固醇和蛋白质吸收的增强与食糜通过回肠的流速降低有关。喂食酪蛋白的猪粪便中胆汁酸的排出量减少，而回肠排出量没有受到显著影响。这可能归因于从盲肠和/或结肠对胆汁酸的摄取增加，这可能部分与间接观察到的次级胆汁酸形成减少有关。喂食酪蛋白的猪餐后血清胰岛素和葡萄糖浓度暂时升高，而甘油三酯浓度降低。我们认为胆固醇和胆汁酸排泄的减少是酪蛋白诱导猪高胆固醇血症的主要决定因素。
