Muscle changes with high-intensity aerobic training in an animal model of renal disease

Abstract Purpose: To analyze the muscle changes with high-intensity aerobic training (HIAT) in an animal model of renal disease (RD). Methods: Twenty one adult Wistar rats were divided into 3 groups: healthy sedentary (HS), RD sedentary (RDS), RD aerobic training (RDAT). RDS and RDAT were subjected to unilateral renal ischemia-reperfusion (10 min) and 21days after that, RDAT was subjected to 6 weeks HIAT (swimming). Serum creatinine (Cr) and muscle morphometry (cross-sectional area = CSA) of gastrocnemius were analyzed. Results: Cr was higher (p = 0.0053) in RDS (0.82 ± 0.04) than in the others (RDAT 0.55 ± 0.04; HS 0.55 ± 0.04). Morphometric analysis (class interval of CSA in μm2/absolute frequency of muscle fibers in each class) indicated that 50th percentile occurred in: HS 7th class (3000.00-3499.00/515), RDS, 8th class (3500.00-3999.00/484), RDAT 5th class (2000.00-2499.00/856). CSA of largest fibers in RDS, RDAT, HS was 9953.00 μm2, 9969.00 μm2,11228.00 μm2, respectively. High frequency of fibers with lower CSA occurred in 4th, 5th, 6th and 7th class in RDA, absence of fibers into 22nd, 23rd classes (RDS and RDAT). Conclusion: HIAT in an animal model of RD resulted in increased the number of muscle fibers with smaller CSA.

摘要
研究目的：分析高强度有氧训练（high-intensity aerobic training, HIAT）对肾病（renal disease, RD）动物模型的肌肉形态变化的影响。
方法：选取21只成年Wistar大鼠，随机分为3组：健康静息组（healthy sedentary, HS）、肾病静息组（renal disease sedentary, RDS）、肾病有氧训练组（renal disease aerobic training, RDAT）。RDS组与RDAT组均接受单侧肾缺血再灌注（10 min）造模，造模21天后，RDAT组接受为期6周的HIAT游泳训练。检测各组大鼠血清肌酐（serum creatinine, Cr）水平及腓肠肌的肌纤维横截面积（cross-sectional area, CSA）等肌肉形态计量学指标。
结果：RDS组血清肌酐水平为0.82±0.04，显著高于其余两组（RDAT组0.55±0.04；HS组0.55±0.04，p=0.0053）。形态计量学分析（以μm²为肌纤维横截面积区间的各组肌纤维绝对频数分布）显示，肌纤维横截面积50百分位数所在区间分别为：HS组第7区间（3000.00~3499.00μm²/515）、RDS组第8区间（3500.00~3999.00μm²/484）、RDAT组第5区间（2000.00~2499.00μm²/856）。三组最大肌纤维横截面积分别为：RDS组9953.00μm²、RDAT组9969.00μm²、HS组11228.00μm²。RDA组低横截面积肌纤维的频数集中于第4、5、6、7区间，且RDS组与RDAT组均未检测到第22、23区间的肌纤维。
结论：肾病动物模型接受HIAT后，小横截面积肌纤维的数量显著增加。