Dietary 20:4n-6 and 22:6n-3 modulates the profile of long- and very-long-chain fatty acids, rhodopsin content, and kinetics in developing photoreceptor cells

作     者：Suh, M Wierzbicki, AA Lien, EL Clandinin, MT 

作者机构：Univ Alberta Dept Agr Food & Nutritional Sci Nutr & Metab Res Grp Agr Forestry Ctr 4 10 Edmonton AB T6G 2P5 Canada Univ Alberta Dept Med Edmonton AB T6G 2P5 Canada Wyeth Ayerst Res Philadelphia PA USA 

出 版 物：《PEDIATRIC RESEARCH》 (儿科研究)

年 卷 期：2000年第48卷第4期

页      面：524-530页

核心收录：

学科分类：1002[医学-临床医学] 100202[医学-儿科学] 10[医学] 

主　　题：细胞膜/化学 膳食脂肪类/药理学 脂肪酸类/分析 脂肪酸类/药理学 食品 配方 动力学 磷脂酰胆碱类/分析 磷脂酰乙醇胺类/分析 磷脂酰丝氨酸类/分析 磷脂类/分析 光感受器/化学 光感受器/生长和发育 光感受器/超微结构 大鼠 Sprague-Dawley 视网膜/化学 视网膜/生长和发育 视紫质/分析 视紫质/代谢 视杆外段/化学 视杆外段/生长和发育 动物 大鼠 

摘      要：The objective of this study was to determine whether addition of dietary 20:4n-6 and 22:6n-3 to a conventional infant formula fat blend influences membrane long-chain and very-long-chain fatty acid composition, rhodopsin content, and rhodopsin kinetics in developing rat photoreceptor cells. The dietary fats were formulated based on the fat composition of a conventional infant formula providing an 18:2n-6/18:3n-3 ratio of 7:1 (SMA, Wyeth Nutritionals), which served as the control fat blend. This dietary fat blend was modified to contain 20:4n-6 [arachidonic acid (AA)], 22:6n-3 [docosahexaenoic acid (DHA)], AA + DHA, or an 18:2n-6/18:3n-3 ratio of 4:1 (alpha-linolenic acid). Darns were fed diets from birth, and rat pups were fed the same diet after weaning. Retinas and rod outer segments were prepared in the dark from pups at 2, 3, and 6 wk of age for fatty acid analysis of individual phospholipids, rhodopsin content, and rhodopsin disappearance kinetics after light exposure. Feeding AA + DHA in the diet increased 22:6n-3 levels in phosphatidylcholine and phosphatidylethanolamine. In phosphatidylcholine, total n-6 tetraenoic very-long-chain fatty acids and total n-3 pentaenoic and n-3 hexaenoic very-long-chain fatty acids increased after feeding AA and DHA, respectively. Developmental changes were characterized by a decrease in 20:4n-6 in the major phospholipids, whereas 22:6n-3 increased with age in rod outer segments. The highest rhodopsin content occurred in the retina of rats fed diets containing AA and/or DHA, The kinetics of rhodopsin disappearance after light exposure was highest in rats fed DIIA at 6 wk of age. This study demonstrates that small manipulations of the dietary level of 20:4n-6 and 22:6n-3 are important determinants of fatty acid composition of membrane lipid and visual pigment content and kinetics in the developing photoreceptor cell.