Ha T Y, Otsuka M, Arakawa N
Department of Food and Nutrition, Ochanomizu University, Tokyo, Japan.
J Nutr Sci Vitaminol (Tokyo). 1990 Jun;36(3):227-34. doi: 10.3177/jnsv.36.227.
Ascorbic acid (AsA) is known to be required for the synthesis of carnitine. The present study was designed to clarify the effect of AsA on the carnitine synthesis and lipid metabolism in guinea pigs. The animals were divided into four groups, and fed AsA-free diets for three weeks. Each group was supplemented with AsA in the following doses; high-AsA group, 100 mg AsA/day/animal; control group, 5 mg AsA/day/animal; AsA-deficient group, 0.1 mg AsA/day/animal; pair-fed group, 5 mg AsA/day/animal. The pair-fed group was restricted to the amount of diet consumed by the AsA-deficient group. Tissue carnitine levels of the AsA-deficient group were significantly lower than not only the control group but the pair-fed group. Total cholesterol and phospholipid levels in plasma of the AsA-deficient group were found to be similar to those of the pair-fed group; however, plasma triglyceride levels were significantly higher than that of the pair-fed group. Furthermore, there was an inverse relationship between tissue AsA and plasma triglyceride levels. We concluded that carnitine synthesis and triglyceride metabolism in guinea pigs may be impaired by the decrease of tissue AsA level rather than by the insufficient food intake. It is suggested that tissue carnitine level altered by tissue AsA content affects plasma triglyceride level.
已知合成肉碱需要抗坏血酸（AsA）。本研究旨在阐明AsA对豚鼠肉碱合成及脂质代谢的影响。将动物分为四组，给予无AsA饮食三周。每组补充以下剂量的AsA：高AsA组，100mg AsA/天/只动物；对照组，5mg AsA/天/只动物；AsA缺乏组，0.1mg AsA/天/只动物；配对喂养组，5mg AsA/天/只动物。配对喂养组的饮食量限制在AsA缺乏组所消耗的量。AsA缺乏组的组织肉碱水平不仅显著低于对照组，也低于配对喂养组。发现AsA缺乏组血浆中的总胆固醇和磷脂水平与配对喂养组相似；然而，血浆甘油三酯水平显著高于配对喂养组。此外，组织AsA与血浆甘油三酯水平呈负相关。我们得出结论，豚鼠的肉碱合成和甘油三酯代谢可能因组织AsA水平降低而非食物摄入不足而受损。提示组织AsA含量改变的组织肉碱水平会影响血浆甘油三酯水平。
