Perin N, Jarocka-Cyrta E, Keelan M, Clandinin T, Thomson A
Department of Medicine, University of Alberta, Edmonton, Canada.
J Pediatr Gastroenterol Nutr. 1999 Jan;28(1):46-53. doi: 10.1097/00005176-199901000-00012.
Varying lipid content of the diet of pregnant and nursing dams results in alterations in sugar and lipid uptake into the intestine of their suckling offspring. In this study, we wished to determine whether the same alterations in dietary lipid result in adaptation of intestinal transport in postweaning rats.
During nursing, the dams were fed the same diet that their offspring were fed for 3 more weeks after weaning. These semipurified diets contained: 1) 15.8% of total fatty acids (w/w) as 18:2n-6 and an n6/n3 ratio of 7.3:1; 2) a diet with 17.6% of total fatty acids as 18:2n-6 and an n6/n3 ratio of 4:1; 3) a diet with 16.2% of total fatty acids as 18:2n-6 and 1.2% arachidonic acid (AA); 4) a diet with 16.8% of total fatty acids at 18:2n-6, 1.2% AA and 0.7% docosahexaenoic acid (DHA); and 5) a diet with 16.0% of total fatty acids as 18:2n-6 and 0.7% as DHA. The in vitro uptake of D-glucose, D-fructose, medium- or long-chain fatty acids and cholesterol was assessed in 6-week-old rats.
Feeding AA increased the Vmax for jejunal and ileal uptake of glucose, compared with the high n6/n3 diet. This effect was prevented by adding DHA to the AA diet. The low n6/n3 fatty acid ratio diet decreased uptake of fructose as compared with the high n6/n3 diet, and the increased uptake of fructose with DHA was prevented by adding AA. The incremental change in free energy associated with uptake of medium chain-length fatty acids was lower in the jejunum of animals fed AA plus DHA as compared with the other diet groups. Jejunal uptake of 18:0 was lower for animals fed DHA or AA plus DHA, as compared with AA alone; ileal rate of uptake of long-chain fatty acids was unaffected by diet.
The intestine of young rats modifies its intestinal morphology and adapts its nutrient transport in response to variations in dietary lipids. In postweaning rats, the potentially undesirable effect of one fatty acid on nutrient uptake may be countered by adding a select second fatty acid to the diet.
怀孕和哺乳母鼠饮食中脂质含量的变化会导致其哺乳后代肠道对糖和脂质的摄取发生改变。在本研究中，我们想确定饮食脂质的相同变化是否会导致断奶后大鼠肠道转运的适应性改变。
在哺乳期间，母鼠喂食与它们的后代断奶后再喂食3周相同的饮食。这些半纯化饮食包含：1）总脂肪酸的15.8%（w/w）为18:2n-6，n6/n3比例为7.3:1；2）一种饮食，总脂肪酸的17.6%为18:2n-6，n6/n3比例为4:1；3）一种饮食，总脂肪酸的16.2%为18:2n-6，花生四烯酸（AA）含量为1.2%；4）一种饮食，总脂肪酸的16.8%为18:2n-6，AA含量为1.2%，二十二碳六烯酸（DHA）含量为0.7%；5）一种饮食，总脂肪酸的16.0%为18:2n-6，DHA含量为0.7%。在6周龄大鼠中评估D-葡萄糖、D-果糖、中链或长链脂肪酸以及胆固醇的体外摄取情况。
与高n6/n3饮食相比，喂食AA可增加空肠和回肠对葡萄糖的摄取Vmax。在AA饮食中添加DHA可防止这种作用。与高n6/n3饮食相比，低n6/n3脂肪酸比例饮食降低了果糖的摄取，而添加AA可防止DHA导致的果糖摄取增加。与其他饮食组相比，喂食AA加DHA的动物空肠中与中链长度脂肪酸摄取相关的自由能增量变化更低。与单独喂食AA相比，喂食DHA或AA加DHA的动物空肠对18:0的摄取更低；饮食对回肠长链脂肪酸的摄取速率没有影响。
幼鼠的肠道会根据饮食脂质的变化改变其肠道形态并调整其营养物质转运。在断奶后大鼠中，通过在饮食中添加特定的第二种脂肪酸，可以抵消一种脂肪酸对营养物质摄取的潜在不良影响。
