Kerner J, Hoppel C
Department of Veteran Affairs Medical Center, Department of Nutrition, Cleveland, USA.
Annu Rev Nutr. 1998;18:179-206. doi: 10.1146/annurev.nutr.18.1.179.
Carnitine functions as a substrate for a family of enzymes, carnitine acyltransferases, involved in acyl-coenzyme A metabolism and as a carrier for long-chain fatty acids into mitochondria. Carnitine biosynthesis and/or dietary carnitine fulfill the body's requirement for carnitine. To date, a genetic disorder of carnitine biosynthesis has not been described. A genetic defect in the high-affinity plasma membrane carnitine-carrier(in) leads to renal carnitine wasting and primary carnitine deficiency. Myopathic carnitine deficiency could be due to an increase in efflux moderated by the carnitine-carrier(out). Defects in the carnitine transport system for fatty acids in mitochondria have been described and are being examined at the molecular and pathophysiological levels. the nutritional management of these disorders includes a high-carbohydrate, low-fat diet and avoidance of those events that promote fatty acid oxidation, such as fasting, prolonged exercise, and cold. Large-dose carnitine treatment is effective in systemic carnitine deficiency.
肉碱作为一类酶（肉碱酰基转移酶）的底物发挥作用，这些酶参与酰基辅酶A代谢，并且作为长链脂肪酸进入线粒体的载体。肉碱的生物合成和/或膳食中的肉碱满足了身体对肉碱的需求。迄今为止，尚未描述肉碱生物合成的遗传性疾病。高亲和力质膜肉碱载体（in）的遗传缺陷会导致肾性肉碱消耗和原发性肉碱缺乏。肌病性肉碱缺乏可能是由于肉碱载体（out）调节的流出增加所致。线粒体中脂肪酸的肉碱转运系统缺陷已被描述，并且正在分子和病理生理水平上进行研究。这些疾病的营养管理包括高碳水化合物、低脂饮食，并避免那些促进脂肪酸氧化的情况，如禁食、长时间运动和寒冷。大剂量肉碱治疗对全身性肉碱缺乏有效。
