INHIBITION OF THE ADRENERGIC DEPRESSOR RESPONSE

¹ Department of Pharmacology, Medical College of Georgia, Augusta

The effects of 22 compounds upon the depressor response to epinephrine after phenoxybenzamine and Dibenamine have been determined in anesthetized dogs.

Only ephedrine and methoxamine were found to be capable of reversing the epinephrine depressor effect to a pressor effect. This action of ephedrine and methoxamine is possibly mediated through their ability to displace the adrenergic blocking agent from its site of action. If this displacement of the adrenergic blocking agent is of sufficiently long duration, then the epinephrine depressor effect does not return.

This action of ephedrine and methoxamine is not characteristic of the adrenergic agents as a class since 17 other compounds were tested in a similar manner and none were found to be effective.