DANTROLENE SODIUM PROTECTS AGAINST EXPERIMENTAL-ISCHEMIA AND REPERFUSION DAMAGE TO SKELETAL-MUSCLE

The effect of 4 hours of ischemia followed by reperfusion for 1 hour h as been studied in fully anesthetized rabbits. Muscles from the limb s ubjected to ischemia and reperfusion showed considerable ultrastructur al damage, although the distribution of damage between muscles was not uniform (anterior tibialis > soleus > quadriceps). Damage to the musc le was associated with a significant increase in the concentration of some indicators of free radical-mediated processes (thiobarbituric aci d-reactive substances and diene conjugates), although others (glutathi one and protein sulfhydryl groups) were unchanged. Reperfused muscles also showed considerable changes in their calcium and sodium contents. Treatment of animals with dantrolene sodium (4 mg/hr) throughout the periods of ischemia and reperfusion was found to preserve the ultrastr uctural appearance of quadriceps, soleus and anterior tibialis muscles . No effect of dantrolene sodium on indicators of free radical activit y or muscle cation content was seen.