Tiidus P M, Holden D, Bombardier E, Zajchowski S, Enns D, Belcastro A
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada.
Can J Physiol Pharmacol. 2001 May;79(5):400-6.
We hypothesized that estrogen administration would attenuate skeletal muscle neutrophil infiltration, indices of muscle membrane disruption, and muscle calpain activity shortly after the termination of exercise. Ovariectomized female rats were implanted with either an estogen pellet (25 mg beta-estradiol) or a placebo pellet. Two weeks postimplant, animals were killed either at rest or 1 h after running exercise (60 min at 21 m x min(-1), 12% grade). The 4 experimental groups (n = 12) used were: unexercised placebo (UP), unexercised estrogen (UE), exercised placebo (EP), and exercised estrogen (EE). Blood samples were analyzed for creatine kinase (CK) activity and estradiol content. Plantaris and gastrocnemius muscles were removed and histochemical determination of neutrophil content or biochemical determination of myeloperoxidase (MPO), glucose-6-phosphate dehydrogenase (G6PD), and calpain-like activity determined. Estrogen supplemented animals had 10-20-fold higher circulating estradiol levels than placebo animals. EP animals had significantly higher (P < 0.05) circulating CK activities than EE or unexercised animals. Muscle neutrophil concentrations were significantly (P < 0.01) elevated in EP and EE groups compared with unexercised controls, with EP muscle neutrophil levels also being over 60% greater (P < 0.05) than in EE animals. EP animals also had higher (P < 0.05) muscle MPO activities than unexercised or EE animals. Muscle G6PD activities were not significantly different between any groups. Muscle caplain-like activities were 80% higher (P < 0.01) in EP animals than EE animals with calpain-like activities in EE animals similar to unexercised groups. These results indicate that estrogen supplementation in ovariectomized rats attenuated 1-h post-exercise serum CK activities, muscle neutrophil infiltration, MPO activities, and calpain-like activities when compared with exercised, unsupplemented animals. This supports the possibility of a relationship between estrogen, calpain dependent production of neutrophil chemo-attractant peptides, and 1-h post-exercise skeletal muscle neutrophil infiltration.
我们假设，在运动结束后不久给予雌激素会减轻骨骼肌中的中性粒细胞浸润、肌膜破坏指标以及肌肉钙蛋白酶活性。对去卵巢的雌性大鼠植入雌激素药丸（25毫克β-雌二醇）或安慰剂药丸。植入两周后，在动物休息时或跑步运动（以21米/分钟的速度、12%的坡度跑60分钟）后1小时将其处死。所使用的4个实验组（每组n = 12）分别为：未运动的安慰剂组（UP）、未运动的雌激素组（UE）、运动的安慰剂组（EP）和运动的雌激素组（EE）。分析血样中的肌酸激酶（CK）活性和雌二醇含量。取出比目鱼肌和腓肠肌，通过组织化学方法测定中性粒细胞含量，或通过生化方法测定髓过氧化物酶（MPO）、葡萄糖-6-磷酸脱氢酶（G6PD）以及类钙蛋白酶活性。补充雌激素的动物其循环雌二醇水平比安慰剂组动物高10至20倍。EP组动物的循环CK活性显著高于EE组或未运动的动物（P < 0.05）。与未运动的对照组相比，EP组和EE组肌肉中的中性粒细胞浓度显著升高（P < 0.01），且EP组肌肉中的中性粒细胞水平比EE组动物高60%以上（P < 0.05）。EP组动物的肌肉MPO活性也高于未运动的动物或EE组动物（P < 0.05）。任何组之间的肌肉G6PD活性均无显著差异。EP组动物的肌肉类钙蛋白酶活性比EE组动物高80%（P < 0.01），而EE组动物的类钙蛋白酶活性与未运动组相似。这些结果表明，与运动但未补充雌激素的动物相比，对去卵巢大鼠补充雌激素可减轻运动后1小时的血清CK活性、肌肉中性粒细胞浸润、MPO活性以及类钙蛋白酶活性。这支持了雌激素、钙蛋白酶依赖性中性粒细胞趋化肽产生与运动后1小时骨骼肌中性粒细胞浸润之间存在关联的可能性。
