Myocardial Necroses Produced in Domesticated Rats and in Wild Rats by Sensory and Emotional Stresses.

Wild rats exposed after periods of isolation to frightening noises (tape recording of hissing cat and squealing rat) displayed myocardial necroses in nearly 70% of the experiments. In non-isolated, domesticated white rats, analogous frightening stimuli proved much less cardiotoxic, even after pretreatment with a sensitizing corticoid (fluorocortisol). Frustrating situations (compulsory jumping for food against increasing and confusing obstacles), on the other hand, elicited myocardial lesions in one-third to one-half of corticoid-sensitized white rats. With the exception of one white rat, none of the numerous untreated and corticoid-treated controls showed any myocardial lesions. The presumable joint role of adreno-sympathogenic catecholamine liberation and of adrenal corticoids in the myocardium-necrotizing mechanism of sensory and emotional stresses, and its clinical implications, are briefly discussed.