目的:探讨葡萄糖转运蛋白1(glucose transporter 1)基因第2内含子上G22999T单核苷酸多态性(SNP)与HiHiLo(living high-exercise high-training low)对递增负荷运动中左心室结构和动态心功能的影响的关联关系。方法:采用关联分析(Association—Study)研究方法,聚合酶链反应-限制片段长度多态性(PCR-RFLP)技术,选取72名健康受试者,在模拟海拔2500米高度进行4周低氧训练(低氧暴露10h/d,3次75%VO2max低氧训练/周,共4周)。实验前后,运用二维及Doppler超声心动图技术,分别于HiHiLo前后测量72名受试者在递增负荷全过程中的心脏结构指标、收缩功能指标及舒张功能指标。结果:(1)GLUT1基因SNP/G22999T经扩增、酶切后得到GG、GT和TT三种基因型,符合Hardy-Weinberg遗传平衡定律,具有群体代表性。(2)GLUT1基因SNP/G22999T多态位点T等位基因携带者短轴缩短率(SF)减小量、递增负荷实验100W负荷下ESV减小量和50W、100W负荷下的EDT增加量均明显高于未携带T等位基因者。结论:SNP/G22999T多态位点T等位基因携带者较非携带者对HiHiLo训练更敏感,但将该多态位点作为筛选HiHiLo对左心室结构和功能影响效果的分子标记还需加大样本进一步研究。
Objective The purpose of the study is to explore the association between glucose transporter 1 (GLUT1) gene SNP/G22999T polymorphism and exercise-induced structure and function of left ventricle during HiHiLo (Living high-exercise high-training low). Methods Seventy-two healthy subjects participated in four-week HiHiLo (10-hour hypoxic exposure per day and 3 times hypoxic training per week with the intensity of 75% VO2max). The genotype and the EDD, ESD, LVM, SV, EF, and CO were analyzed by PCR-RFLP and 2D and Doppler echocardiography respectively during the graded exercise before and after HiHiLo. Results (1)After PCR amplification and digestion with Xba 1, three genotypes were observed: G/G, G/T and T/T. Genotype distributions were in Hardy-Weinberg equilibrium. In SNP/G22999T polymorphism T allele carriers, decreasing level of shortening fraction (SF) and ESV under 100W exercise, and increasing level of EDT under 50W and 100W exercise were significantly greater than in those without carrying SNP/G22999T polymorphism T allele after HiHiLo. Conclusion Although higher sensitivity to the HiHiLo reveals in allele T carriers than those without allele T, however SNP/G22999T polymorphism as a molecular marker in predicting the effects of HiHiLo on left ventricular structure and function still needs further study.