No association between hyponatremia and rhabdomyolysis in rats.
BACKGROUND
Rhabdomyolysis is an uncommon complication of hyponatremia, reported previously only in case reports and small retrospective studies, and its underlying mechanism is controversial. Some studies support the hypothesis that the rapid correction of hyponatremia is responsible for rhabdomyolysis, whereas others emphasize the severity of the hyponatremia as a predisposing factor for rhabdomyolysis.


OBJECTIVE
To test the association between hyponatremia and rhabdomyolysis and to demonstrate a causal association.


METHODS
Hyponatremia was induced by administration of water and desmopressin acetate in rats during 3 days, followed by its rapid correction, using animal models established for the evaluation of central pontine myelinolysis. The plasma creatine phosphokinase levels, a marker for rhabdomyolysis, were monitored, and hematoxylin and eosin sections of the quadriceps and gastrocnemius muscles were evaluated for signs of rhabdomyolysis.


RESULTS
The induction of hyponatremia and its correction were accompanied by the previously reported neurological sequelae, including signs of central pontine myelinolysis. However, no increase in plasma creatine phosphokinase levels was found, and histopathological examination of the quadriceps and gastrocnemius muscles revealed no sign of rhabdomyolysis.


CONCLUSIONS
The present study, which is the first to test the association between hyponatremia and rhabdomyolysis in an animal model, does not support any causal association between hyponatremia and rhabdomyolysis. Thus, other factors might be necessary for an association between hyponatremia and rhabdomyolysis, such as genetic factors or convulsions that are known to be associated with both hyponatremia and rhabdomyolysis. Further research in this important physiologic and clinical question is needed.
Department of Internal Medicine, Tel Aviv Sourasky Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Michael
M
Peled
Orthopedic Division, Tel Aviv Sourasky Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Oleg
O
Dolkart
Department of Internal Medicine, Tel Aviv Sourasky Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Talya
T
Finn
Orthopedic Division, Tel Aviv Sourasky Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Eyal
E
Amar
Department of Internal Medicine, Tel Aviv Sourasky Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
David
D
Zeltser
D000704:Analysis of Variance; D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D004195:Disease Models, Animal; D007010:Hyponatremia / Q000097:blood / Q000150:complications* / Q000188:drug therapy; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012189:Retrospective Studies; D012206:Rhabdomyolysis / Q000097:blood / Q000209:etiology* / Q000473:pathology; D012964:Sodium / Q000097:blood
D012964:Sodium; D003402:Creatine Kinase
convulsion; desmopressin; hyponatremia; rat; rhabdomyolysis