Powers S K, Wade M, Criswell D, Herb R A, Dodd S, Hussain R, Martin D
Department of Exercise and Sport Sciences, University of Florida, Gainesville, USA.
Int J Sports Med. 1995 Jan;16(1):13-8. doi: 10.1055/s-2007-972956.
To test the hypothesis that beta-adrenergic stimulation is required for the normal increase in oxidative capacity of respiratory and locomotor skeletal muscle in response to exercise training, we examined the effects of beta-blockade on muscle oxidative capacity in trained and sedentary rats. Thirty-four female adult Sprague-Dawley rats were randomly divided into four experimental groups: 1) trained+propranolol (TP); 2) trained + sham injection (TS); 3) sedentary + propranolol (SP); and 4) sedentary + sham injection (SS). Training increased (p < 0.05) citrate synthase (CS) activity in the plantaris (+29%) and costal diaphragm (+12%) of TS animals compared to SS animals. In contrast, training did not (p > 0.05) increase costal diaphragm CS activity in TP animals compared to the SS group. Further, although training increased (p < 0.05) plantaris CS activity in the TP group (+18%) compared to the SP group, the training-induced increase in muscle CS activity was 11% lower (p < 0.05) than observed in TS animals. Collectively, these results suggest that beta-adrenergic mechanisms may play a role in the normal training-induced increase in oxidative capacity in both respiratory and locomotor skeletal muscles.
为了验证β-肾上腺素能刺激是运动训练引起呼吸和运动骨骼肌氧化能力正常增加所必需的这一假设，我们研究了β-受体阻滞剂对训练有素和久坐不动的大鼠肌肉氧化能力的影响。34只成年雌性Sprague-Dawley大鼠被随机分为四个实验组：1）训练+普萘洛尔（TP）；2）训练+假注射（TS）；3）久坐+普萘洛尔（SP）；4）久坐+假注射（SS）。与SS组相比，训练使TS组动物的比目鱼肌（+29%）和肋膈膜（+12%）中的柠檬酸合酶（CS）活性增加（p<0.05）。相比之下，与SS组相比，训练并未使TP组动物的肋膈膜CS活性增加（p>0.05）。此外，尽管与SP组相比，训练使TP组比目鱼肌的CS活性增加（p<0.05）（+18%），但训练诱导的肌肉CS活性增加比TS组动物低11%（p<0.05）。总体而言，这些结果表明，β-肾上腺素能机制可能在运动训练诱导的呼吸和运动骨骼肌氧化能力正常增加中发挥作用。
