EFFECT OF DANTROLENE SODIUM ON FIBRILLATION POTENTIALS IN DENERVATED RAT MUSCLES

To examine whether a decrease in cytosolic Ca2+ affects fibrillation p otentials, we studied effects of dantolene on these potentials in dene rvated rat muscle. Administered intraperitoneally, dantrolene sodium ( 12-22 mg/kg) abolished fibrillation potentials and subthreshold oscill ating potentials over 2.5-6 h without affecting excitability of the mu scle to electrical stimulation. Fibrillation potentials reappeared 36- 96 h after administration of dantrolene. We suggest that cytosolic Ca2 + has a specific role in generating fibrillations. (C) 1998 John Wiley & Sons, Inc.