Elevated myoplasmic calcium in exercise-induced equine rhabdomyolysis.
Exertional rhabdomyolysis is a myopathy of unknown pathophysiology. We measured intracellular resting calcium concentration ([Ca2+]i) by means of Ca(2+)-selective microelectrodes in intercostal muscle fibers from horses suffering from rhabdomyolysis, and from horses with no evidence of neuromuscular disorder. [Ca2+]i was several-fold higher in muscle fibers from horses suffering from rhabdomyolysis when compared to controls. Treatment of rhabdomyolytic horses with dantrolene, an agent that prevents Ca2+ release from the sarcoplasmic reticulum, reduced [Ca2+]i toward control values, and accelerated the recovery from this myopathy. These results indicate that an acute episode of rhabdomyolysis is associated with elevation in [Ca2+]i in skeletal muscles, and that dantrolene might be of benefit in treating this disease.
López
J R
JR
Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas.
Linares
N
N
Cordovez
G
G
Terzic
A
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003620:Dantrolene / Q000627:therapeutic use; D006734:Horse Diseases / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D006736:Horses; D008839:Microelectrodes; D018482:Muscle, Skeletal / Q000378:metabolism*; D005082:Physical Exertion; D012206:Rhabdomyolysis / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
D003620:Dantrolene; D002118:Calcium