Effects of changes in plasma volume on fatal rhabdomyolysis in the rat induced by glycerol injections

Rhabdomyolysis can be fatal in both experimental animals and man, but very little is known of the factors causing increased mortality in rhabdomyolysis. The aims of this study were to create an animal model of fatal rhabdomyolysis in rats by a glycerol injection into the leg muscle, and to elucidate some of the factors affecting mortality as a result of rhabdomyolysis formation. In this study, two factors which can result in increased mortality in rats as a result of glycerol injection, were examined. These factors include varying doses of 50% glycerol (0.5-2 ml/100 g) and various stages of dehydration prior to glycerol injection. Dehydration was induced by 1: chronic dehydration, in which the rats underwent water deprivation for a period of 24 to 72 hours prior to injection of glycerol; 2: acute dehydration, by the induction of either diuresis, by injecting sucrose (200-600 mg/100 g) to the femoral vein, or hemorrhage (0.7-2.1 ml/100 g). The results demonstrate that the mortality rate in rats increased in all three models of dehydration as the dose of glycerol injected to the rats increased (above a dose of 0.75 ml/100 g) and as the extent of dehydration increased. Use of a blood substitute before or after glycerol injection in order to compensate for the loss of body fluids did not increase the survival rate of the glycerol-injected rats. In contradistinction, rats treated with non-lethal doses of glycerol exhibited substantial resistance to a second lethal dose of glycerol, injected two weeks following the first injection.