Tuazon Marc A, McConnell Taylor R, Wilson Gabriel J, Anthony Tracy G, Henderson Gregory C
Department of Exercise Science, Rutgers University, New Brunswick, New Jersey; Center for Lipid Research, Rutgers University, New Brunswick, New Jersey.
Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey; and Center for Lipid Research, Rutgers University, New Brunswick, New Jersey.
J Appl Physiol (1985). 2015 Jan 1;118(1):61-70. doi: 10.1152/japplphysiol.00440.2014. Epub 2014 Sep 25.
Precise regulation of hepatic triglyceride (TG) metabolism and secretion is critical for health, and exercise could play a significant role. We compared one session of high-intensity interval exercise (HIIE) vs. continuous exercise (CE) on hepatic TG metabolism. Female and male mice were assigned to CE, HIIE, or sedentary control (CON). HIIE was a 30-min session of 30-s running intervals (30 m/min) interspersed with 60-s walking periods (5 m/min). CE was a distance- and duration-matched run at 13.8 m/min. Hepatic content of TG and TG secretion rates, as well as expression of relevant genes/proteins, were measured at 3 h (day 1) and 28 h (day 2) postexercise. On day 1, hepatic [TG] in CE and HIIE were both elevated vs. CON in both sexes with an approximately twofold greater elevation in HIIE vs. CE in females. In both sexes, hepatic perilipin 2 (PLIN2) protein on day 1 was increased significantly by both exercise types with a significantly greater increase with HIIE than CE, whereas the increase in mRNA reached significance only after HIIE. On day 2 in both sexes the increases in hepatic TG and PLIN2 with exercise declined toward CON levels. Only HIIE on day 2 resulted in reduced hepatic TG secretion by ∼20% in females with no effect in males. Neither exercise modality altered AMPK signaling or microsomal triglyceride transfer protein expression. Females exhibited higher hepatic TG secretion than males in association with different expression levels of related metabolic enzymes. These intensity-dependent and sex-specific alterations following exercise may have implications for sex-based exercise prescription.
肝脏甘油三酯（TG）代谢和分泌的精确调节对健康至关重要，而运动可能发挥重要作用。我们比较了一次高强度间歇运动（HIIE）和持续运动（CE）对肝脏TG代谢的影响。将雌性和雄性小鼠分为CE组、HIIE组或久坐对照组（CON）。HIIE是一次30分钟的运动，包括30秒的跑步间歇（30米/分钟），其间穿插60秒的步行时段（5米/分钟）。CE是一次速度为13.8米/分钟、距离和时长匹配的跑步。在运动后3小时（第1天）和28小时（第2天）测量肝脏TG含量、TG分泌率以及相关基因/蛋白质的表达。在第1天，CE组和HIIE组的肝脏[TG]在两性中均高于CON组，在雌性中HIIE组的升高幅度比CE组大约高两倍。在两性中，两种运动类型在第1天均显著增加了肝脏周脂素2（PLIN2）蛋白，HIIE组的增加幅度显著大于CE组，而mRNA的增加仅在HIIE后达到显著水平。在第2天，两性中运动后肝脏TG和PLIN2的增加均向CON组水平下降。仅第2天的HIIE使雌性肝脏TG分泌减少约20%，对雄性无影响。两种运动方式均未改变AMPK信号传导或微粒体甘油三酯转移蛋白的表达。雌性肝脏TG分泌高于雄性，与相关代谢酶的不同表达水平有关。运动后这些强度依赖性和性别特异性的改变可能对基于性别的运动处方有影响。
