Dantrolene sodium diminishes exercise-induced muscle damage in the rat.
We tested the hypothesis that calcium from the sarcoplasmic reticulum contributes to exercise-induced muscle damage. Dantrolene sodium (Dantrium) is a muscle relaxant that affects the flux of calcium over the sarcoplasmic membrane. Rats were treated with dantrolene sodium for a week before a 2 h run on a treadmill. We measured the total creatine kinase activity and isoenzyme composition in plasma before and after exercise. We also prepared muscle sections to correlate the biochemical data with morphological evidence of muscle damage. The treated rats showed a marked decrease (34%) in exercise-induced enzyme efflux, caused by a decrease in the muscle specific isoenzyme: instead of a 13-fold increase found in control rats we observed only a 6.5-fold increase in treated animals. The latter showed significantly less muscle damage 48 h later. It is concluded that dantrolene sodium protects the muscle against exercise-induced damage. The possible mechanism of this protection, and its applications in neuromuscular disease are discussed.
Amelink
G J
GJ
Department of Neurology, University of Utrecht, The Netherlands.
Van der Kallen
C J
CJ
Wokke
J H
JH
Bär
P R
PR
D000818:Animals; D002118:Calcium / Q000378:metabolism; D003402:Creatine Kinase / Q000096:biosynthesis*; D003620:Dantrolene / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D007527:Isoenzymes; D007866:Leg; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000201:enzymology / Q000293:injuries*; D005082:Physical Exertion; D051381:Rats; D013997:Time Factors
D007527:Isoenzymes; D003402:Creatine Kinase; D003620:Dantrolene; D002118:Calcium