Effects of dantrolene sodium on fibrillation potentials in denervated rat muscles

To examine whether a decrease in cytosolic Ca²⁺ affects fibrillation potentials, we studied effects of dantolene on these potentials in denervated rat muscle. Administered intraperitoneally, dantrolene sodium (12–22 mg/kg) abolished fibrillation potentials and subthreshold oscillating potentials over 2.5–6 h without affecting excitability of the muscle 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. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21: 1797–1799, 1998