肌红蛋白基因多态性与运动性肌肉损伤的相关性

摘要

目的 探讨肌红蛋白(myoglobin,Mb)基因第2外显子单核苷酸多态(A79G)与运动性肌肉损伤的关系.方法 85名武警战士进行一次大强度负重运动,检测血清肌酸激酶(creatine kinase,CK)活性的时程变化;聚合酶链反应-限制性片段长度多态(PCR-RFLP)法测定Mb基因多态性;分析基因多态性与安静CK(CKpre)、峰值CK(CKpeak)及CK最大变化值(△CK)的关系.结果 CKpre为(145±33)U/L,大强度运动后24 h开始逐渐升高,72 h达峰值[CKpeak:(2972±1648)]U/L,随后缓慢下降,120 h仍高于安静水平.3种基因型的分布频率分别为AA(54.1%)、AG(40.0%)、GG(5.9%),等位基因分布频率为A(74.1%)、G(25.9%),符合Hardy-Weinberg遗传平衡定律.组间比较,(AG+GG)组CKpre、CKpeak和△CK均高于AA组(均P＜0.01).结论 运动性肌肉损伤易感性与Mb基因第2外显子单核苷酸多态(A79G)有关,G等位基因具有肌肉损伤易感性,而AA基因型则具有运动性肌肉损伤保护作用.%Objective To study the relationship between single nucleotide polymorphism (A79G) and (T109C) in the second exon of the myoglobin gene and exercise — induced muscle damage. Methods Eighty — five soldiers of CAPF performed a strenuous weight — loading exercise and the time course of serum creatine kinase ( CK) activity was measured. Myoglobin gene polymorphism was detected by polymerase chain reaction — restriction fragment length polymorphism (PCR — RFLP) method. Association between resting CK (CKpre) , maximal CK (CKpeak) , maxiaml changes in CK ( ACK) and gene polymorphism was then analysed. Results The activity of CK [ CKpre; (145 ±33) U/L] gradually increased at 24 h after strenuous exercise and reached peak value at 72 h[CKpeak: (2972±1648) U/L], which then slowly reduced, but still higher than rest level at 120 h. The genotype frequencies ( AA = 54. 1% , AG=40.0%, GG=5.9%) and allele frequencies (A = 74.1%, G=25.9%) were coincident with Hardy — Weinberg equilibrium. Compared between groups, CKpre, CKpeak and ACK in ( AG + GG) - group were all higher than those in AA genotype group ( all P <0. 01). Conclusions The single nucleotide polymorphism (A79G) in the second exon of the myoglobin gene might contribute to susceptivity of exercise — induced muscle damage. Subjects with G allele have increased risk for developing muscle damage, whereas AA genotype may have protective effects.