Côté C, Tremblay D, Riverin H, Frémont P, Rogers P A
Muscle Biology Research Group, Laval University Hospital Research Centre, Ste-Foy, Qué., Canada.
Can J Physiol Pharmacol. 1989 Jun;67(6):645-9. doi: 10.1139/y89-103.
We tested the effects of inhibiting the carbonic anhydrase activity of rat soleus and extensor digitorum longus muscles on the isometric contractile properties and the resistance to fatigue. SOL and EDL muscles from female rats were incubated in vitro in the presence of methazolamide, a specific inhibitor of carbonic anhydrase, before determining their contractile properties. Methazolamide had no effects on the contractile properties of the soleus muscle (10(-5) or 10(-3) M) and extensor digitorum longus (10(-3) M), except for the half-relaxation time of the soleus muscle which increased significantly. Values for half-relaxation time were significantly increased with both concentrations of the inhibitor. Muscles were then submitted to a fatigue protocol lasting 30 min. During the fatigue test, no significant difference was observed between control and 10(-5) M methazolamide soleus muscles. In presence of 10(-3) M methazolamide however, the soleus muscle showed a significantly increased resistance to fatigue compared with control preparations. No significant effect was observed with the extensor digitorum longus muscle exposed to 10(-3) M methazolamide. Results are discussed in terms of the presence of two different isoforms of carbonic anhydrase that may be associated with calcium uptake and energy metabolic processes, respectively.
我们测试了抑制大鼠比目鱼肌和趾长伸肌碳酸酐酶活性对其等长收缩特性和抗疲劳能力的影响。在测定雌性大鼠的比目鱼肌（SOL）和趾长伸肌（EDL）的收缩特性之前，将其置于体外，在碳酸酐酶特异性抑制剂甲醋唑胺存在的情况下进行孵育。甲醋唑胺对比目鱼肌（10⁻⁵或10⁻³ M）和趾长伸肌（10⁻³ M）的收缩特性没有影响，除了比目鱼肌的半松弛时间显著增加。两种浓度的抑制剂均使半松弛时间值显著增加。然后让肌肉接受持续30分钟的疲劳试验。在疲劳试验期间，对照比目鱼肌和10⁻⁵ M甲醋唑胺处理的比目鱼肌之间未观察到显著差异。然而，在10⁻³ M甲醋唑胺存在的情况下，与对照制剂相比，比目鱼肌显示出显著增强的抗疲劳能力。暴露于10⁻³ M甲醋唑胺的趾长伸肌未观察到显著影响。根据可能分别与钙摄取和能量代谢过程相关的两种不同碳酸酐酶同工型的存在对结果进行了讨论。
