Effect of beta adrenergic blockade on surviving to acute hypoxia in mice.

A significant protection against the lethal effects of hypobaric and isobaric hypoxia is observed in mice treated with propranolol. Previous acclimatization to chronic hypoxia does not introduce variations on this protective effect of the beta adrenergic blocking drugs. Similar effects were found using histotoxic anoxia provoked by sodium azide administration. A significative reduction of body temperature is observed under the effects of the blockaders. These findings suggest a reduced need of oxygen in the treated animals. Neutralization of the effects of epinephrine released as a consequence of the hypoxic stress is proposed as the protection mechanism.