Serum creatine phosphokinase levels in rats following cold injury.

Abstract

The validity of serum creatine phosphokinase (CPK) as an index of tissue damage due to cold injury was tested in the rat. Immersion of the feet in the freezing mixture (salt and ice, −19°±1°C) for one or five minutes produced reversible and irreversible damage, respectively. The increase in CPK activity over a 5-hr period following freezing showed that the severity and extent of cold injury was associated with the amount of CPK released into the bloodstream. -Exposure of the whole rat to cold air at −29°C for three hours resulted in a highly variable increase in serum CPK two hours after exposure which was related to the degree of hypothermia during the exposure. The extent of hypothermia was also related to the amount of tissue loss estimated two weeks after the exposure. These findings show that the increase in serum CPK after cold injury reflects subsequent tissue loss and might conceivably be useful in early classification of cold injury.