Heart muscle necroses following normobaric hyperoxia: modification by beta-blocking agents and calcium antagonists.

Heart muscle necroses can be produced in rabbits by normobaric hyperoxia. The pathogenesis of these lesions is controversial. In our investigations we found that such necroses can be prevented by beta blockers, but not by a calcium antagonist. This can be explained by the different action of the two drugs on the coronary arteries. The result supports the view that heart muscle necroses after normobaric hyperoxia are a direct toxic effect of oxygen on the heart muscle fibers.