Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafi ra s/n, Las Palmas de Gran Canaria, 35017, Spain.
Br J Sports Med. 2011 Feb;45(2):95-100. doi: 10.1136/bjsm.2009.060285. Epub 2009 Jul 16.
The exon-1 of the androgen receptor (AR) gene contains two repeat length polymorphisms which modify either the amount of AR protein inside the cell (GGN(n), polyglycine) or its transcriptional activity (CAG(n), polyglutamine). Shorter CAG and/or GGN repeats provide stronger androgen signalling and vice versa. To test the hypothesis that CAG and GGN repeat AR polymorphisms affect muscle mass and various variables of muscular strength phenotype traits, the length of CAG and GGN repeats was determined by PCR and fragment analysis and confirmed by DNA sequencing of selected samples in 282 men (28.6 ± 7.6 years). Individuals were grouped as CAG short (CAG(S)) if harbouring repeat lengths of ≤ 21 and CAG long (CAG(L)) if CAG >21. GGN was considered short (GGN(S)) or long (GGN(L)) if GGN ≤ 23 or >23, respectively. No significant differences in lean body mass or fitness were observed between the CAG(S) and CAG(L) groups, or between GGN(S) and GGN(L) groups, but a trend for a correlation was found for the GGN repeat and lean mass of the extremities (r=-0.11, p=0.06). In summary, the lengths of CAG and GGN repeat of the AR gene do not appear to influence lean mass or fitness in young men.
雄激素受体 (AR) 基因的外显子 1 包含两个重复长度多态性，它们分别修饰细胞内的 AR 蛋白量（GGN(n)，多聚甘氨酸）或其转录活性（CAG(n)，多聚谷氨酰胺）。较短的 CAG 和/或 GGN 重复提供更强的雄激素信号，反之亦然。为了检验 CAG 和 GGN 重复 AR 多态性是否影响肌肉质量和肌肉力量表型特征的各种变量的假设，通过 PCR 和片段分析确定 CAG 和 GGN 重复的长度，并通过对 282 名男性（28.6±7.6 岁）的选定样本进行 DNA 测序进行确认。如果重复长度≤21，则将个体分组为 CAG 短（CAG(S)），如果 CAG >21，则将个体分组为 CAG 长（CAG(L)）。如果 GGN ≤ 23 或>23，则 GGN 分别被认为是短（GGN(S)）或长（GGN(L)）。在 CAG(S)和 CAG(L)组之间，或在 GGN(S)和 GGN(L)组之间，观察到瘦体重或健康状况没有显著差异，但发现 GGN 重复与四肢瘦体重之间存在相关性的趋势（r=-0.11，p=0.06）。总之，AR 基因的 CAG 和 GGN 重复长度似乎不会影响年轻男性的瘦体重或健康状况。
