ADRENAL MEDULLARY STIMULATION AS THE CHIEF BASIS FOR VASOPRESSOR ACTION AND CARDIAC STIMULATION BY VANILLIC ACID DIETHYLAMIDE

¹ Department of Pharmacology and Therapeutics, Medical College of South Carolina, Charleston, South Carolina

Vanillic acid diethylamide (VAD), injected intraaortically, intravertebrally, intracarotid, or intravenously, produced increments in blood pressure and cardiac contractile force. Treatment with TM 10 or atropine, acute cardiac denervation, or spinal transection did not alter significantly the circulatory stimulant responses to VAD injection.

Total preganglionic spinal cord blockade produced by epidural procaine injections blocked circulatory stimulant responses to intravertebral and intracarotid injection of VAD. Responses to intraaortic injection, however, were not significantly decreased.

The cardiac positive inotropic effect of VAD was suppressed by the presence of DCI, while the vasopressor responses of VAD were suppressed by the presence of phentolamine.

VAD produced substantial increases in plasma catecholamine levels. This effect, as well as the circulatory stimulant effects, was not obtained following acute bilateral adrenalectomy.

Under the conditions of the present experiments, the circulatory stimulant action of VAD, produced by whatever route of injection, is dependent on the presence of the adrenal glands.