Changes in the myocardium and skeletal muscle in guinea pigs in cold exposure with and without ethanol.

The effect of hypothermia with and without ethanol on the myocardium and skeletal muscle was studied. Changes were observed in both muscle types. The mildest lesions were discoloration of the muscle cells with acid fuchsin and Heidenhain's iron haematoxylin staining, these being more marked in the skeletal muscle. Waving and contraction bands in the muscle were seen in hypothermia. The most severe lesion was a focus with oedema and haemorrhage, a reduced reaction of beta-hydroxybutyrate dehydrogenase and fragmentation of the muscle cells, and this was more frequent in the myocardium. Occasionally discoloration, contraction bands and waving were also seen in the controls killed by a blow on the neck. The changes were more numerous in the guinea pigs given ethanol before cold exposure, and serum creatinine phosphokinase was elevated in the same group. Urinary excretion of adrenaline increased in cold exposure, but noradrenaline did not change significantly. Hypoxia, catecholamines, and sludging of the blood are discussed as possible aetiological factors for the lesions.