ADRB2基因多形性與台灣耐力運動表現之關聯性探討

Abstract

腎上腺素接受器β2 (adrenergic receptor β2，ADRB2)是分佈廣泛的腎上腺素接受器，；運動刺激神經傳導物質（主要為兒茶酚胺）分泌與ADRB2結合後，引起心跳加速、支氣管擴張、肝醣及脂肪分解上升等生理反應；其對能量代謝及支氣管擴張的影響，讓ADRB2被視為影響耐力運動的可能基因。ADRB2基因位於5q31～32，常提及的基因多形性 (polymorphism)有三個：Arg16Gly（精胺酸變成甘胺酸，A/G）、Gln27Glu（麩胺變成麩胺酸，C/G）及Thr164Ile （酥胺酸變成異白胺酸，C/T）。目前ADRB2基因多形性與耐力運動表現研究較少，結果也不一致，需深入的探討。目的：探討台灣耐力運動表現是否與ADRB2基因有關，且提供台灣的ADRB2基因多形性頻率(frequency)資料。方法：本研究採國內優秀選手（自由車、划船、羽球、足球、網球、桌球及橄欖球選手）142位及一般民眾246位做為控制組之DNA檢體，進行ADRB2基因之判別(PCR -RFLP)；以SPSS 13.0執行χ2-test(α =.05)，考驗台灣優秀耐力運動選手與一般民眾在ADRB2基因是否有差異。結果：Thr164Ile在本次實驗皆為野生型，無變異產生；Arg16Gly與控制組無顯著差異；網球選手與控制組Gln27Glu基因型與allele number達到顯著差異(p=0.019/p=.034)； G allele frequency為23%，較控制組與其他運動高；Gln27Glu控制組的allele number達到性別上差異(p=0.057)。結論：網球選手與控制組Gln27Glu基因型與allele number達到顯著差異，可能與網球強調肌力及速度的特質，在運動能量來源上較趨向爆發力運動有關，Gln27Glu 的G allele的分佈頻率與性別有關，但是否會影響肌力、肌耐力及肌肉生長，及男性激素對於其作用，均有待再研究；G allele或許可以成為較佳的肌力及肌耐力的參考指標。Adrenergic receptor β2(ADRB2) exists in cells such as heart, muscle, vessels, bronchus& lipocyte. ADRB2 combines exercise-induced catecholamines to elevate heartbeat, lipolysis, glycogenolysis & bronchodilation. ADRB2 locates in 5q31~32, three single-nucleotide polymorphisms (SNPs) of ADRB2 (Arg16Gly, Gln27Glu & Thr164Ile) are hypothesize to associate with endurance- performance due to ADRB2’s regulation of cardiopulmonary, lipid metabolism & skeletal muscle. Researches about ADRB2 & endurance-exercise are rare & the results are inconsistent. Exercise-induced mechanisms of ADRB2remain unclear, and more study is necessary. Purpose: To investigate whether ADRB2 SNPs are associated with endurance-exercise performance,& provide frequency data of ADRB2 polymorphism in Taiwan. Methods: We examined 142 elite endurance athletes (road-cycling, rowing, badminton, soccer, tennis, table-tennis & rugby) and 246 healthy people (as controls) from Taiwan general population. ADRB2 genotype was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) form blood-extracted DNA. Differences were evaluated using SPSS 13.0 χ2-test (α= .05). Results: Thr164Ile has no mutation & Arg16Gly genotype did not differ among athletes and controls. Tennis players’ Gln27Glu genotype distribution differ significantly as compare to controls ( p=.034). Gln27Glu allele number is higher in Tennis players (G allele frequency is 23%) than the controls (p=0.019). Gln27Glu allele number also significantly different by genders (p=0.057).Conclusion: The emphasize of muscle strength& speed in Tennis, leading it to anaerobic demand might cause the significant different between Tennis players and the controls. Gln27Glu allele number is associated with gender, whether it affects muscle strength, endurance & growth is unknown. The interaction of androgen also need further study. The G allele of Gln27Glu might be a candidate gene for athletes’ muscle strength & endurance.