背景:多态性rs1049434表征了基因中腺苷(A)被胸苷(T)交换为单羧酸转运蛋白1(MCT1)的非同义交换。我们测试了rs1049434的T等位基因携带者是否表现出代谢菌株标志物的积累增加。
方法:身体活性,健康,年轻男性受试者(n=22)进行了力量匹配的单腿自行车运动,以精疲力竭。毛细血管血液中的代谢底物,选定的代谢化合物,并在运动前后收集的样本中量化了股外侧肌的缓慢氧化表型指标。通过聚合酶链反应确定rs1049434多态性的基因型。
结果:单腿运动影响进入三羧酸循环的肌肉代谢物浓度,如乙酰辅酶A(+448%)和乙酰左旋肉碱(+548%),肌糖原(-59%),和一磷酸腺苷(-39%),运动后30分钟。运动相关的肌肉糖原浓度的变异性,长链酰基辅酶As和甘油三酯,烟酰胺腺嘌呤二核苷酸(NADH),和一磷酸腺苷(AMP)与rs1049434相互作用。当NADH仅在非携带者中增加时,T等位基因携带者运动后糖原的减少比非携带者少39%。肌肉乳酸浓度高出150%,血液三酰甘油酯浓度降低了53%,T等位基因携带者的慢纤维百分比降低了20%。
结论:观察结果表明,在力竭运动过程中,无氧糖酵解菌株较高,而T等位基因非携带者的脂质处理降低。
BACKGROUND: Polymorphism rs1049434 characterizes the nonsynonymous exchange of adenosine (A) by thymidine (T) in the gene for monocarboxylate transporter 1 (MCT1). We tested whether T-allele carriers of rs1049434 demonstrate increased accumulation of markers of metabolic strain.
METHODS: Physically active, healthy, young male subjects (n = 22) conducted a power-matched one-legged cycling exercise to exhaustion. Metabolic substrates in capillary blood, selected metabolic compounds, and indices for the slow oxidative phenotype of vastus lateralis muscle were quantified in samples collected before and after exercise. The genotypes of the rs1049434 polymorphism were determined with polymerase chain reactions.
RESULTS: One-legged exercise affected the concentration of muscle metabolites entering the tricarboxylic acid cycle, such as acetyl-co-enzyme A (+448%) and acetyl-L-carnitine (+548%), muscle glycogen (-59%), and adenosine monophosphate (-39%), 30 min post-exercise. Exercise-related variability in the muscular concentration of glycogen, long-chain acyl co-enzyme As and a triglyceride, nicotinamide adenine dinucleotide (NADH), and adenosine monophosphate (AMP) interacted with rs1049434. T-allele carriers demonstrated a 39% lesser reduction in glycogen after exercise than non-carriers when NADH increased only in the non-carriers. Muscle lactate concentration was 150% higher, blood triacyl-glyceride concentration was 53% lower, and slow fiber percentage was 20% lower in T-allele carriers.
CONCLUSIONS: The observations suggest a higher anaerobic glycolytic strain during exhaustive exercise and a lowered lipid handling in T-allele non-carriers.