期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：2020
卷号：66
期号：2
页码：136-149
DOI：10.3177/jnsv.66.136
出版社：Center for Academic Publications Japan
摘要：The acute metabolic effect of low dosages of L-carnitine under fat-mobilizing conditions was investigated. Healthy subjects (Study 1: n =5; Study 2: n =6) were asked to fast overnight. Then, 30 min of aerobic exercise on a cycle ergometer was performed after supplementation, followed by a 3.5-h sedentary recovery phase. The following ingestion patterns were used: Study 1 (i) noningestion, (ii) 750 mg of L-carnitine (LC), and (iii) 750 mg of LC+50 g of carbohydrate (CHO); Study 2 (iv) noningestion, (v) 500 mg of LC, (vi) 30 mg of CoQ10 , and (vii) 500 mg of LC+30 mg of CoQ10 . The energy expenditure (EE) and nonprotein respiratory quotient (npRQ) were measured during the pre-exercise, postexercise, and recovery periods. Serum free carnitine, acetylcarnitine, total carnitine (Study 1 and 2), and ketone bodies (Study 2) were measured. The 750 mg LC treatment significantly facilitated fat oxidation during the recovery phases ( p <0.05) without elevating EE. The higher fat oxidation associated with LC was completely suppressed by CHO. CoQ10 affected neither npRQ nor EE. npRQ was significantly correlated with the serum total ketone bodies ( R =−0.68, p <0.001) and acetylcarnitine ( R =−0.61-−0.70, p <0.001). The highest correlation was found between acetylcarnitine and total ketone bodies immediately after exercise ( R =0.85, p <0.001). In conclusion, LC enhanced liver fat utilization and ketogenesis in an acute manner without stimulating EE under fat-mobilizing conditions.
