ANGIOTENSIN, COCAINE AND DESIPRAMINE: COMPARISON OF EFFECTS ON BLOOD PRESSURE RESPONSES TO NOREPINEPHRINE, TYRAMINE AND PHENYLEPHRINE IN THE PITHED RAT

¹ Section of Pharmacology, The Norwich Pharmacal Company, Norwich, New York

In the pithed rat, blood pressure responses to norepinephrine were increased after cocaine and desipramine injections and to a lesser extent during angiotensin infusions. Blood pressure responses to phenylephrine and AHR-602 (a ganglion-stimulating agent) were potentiated by desipramine. Blood pressure responses to phenylephrine and AHR-602 were only slightly influenced by cocaine and angiotensin. Desipramine and cocaine significantly inhibited blood pressure responses to tyramine whereas these responses were unchanged during angiotensin infusions. The total radioactivity recoverable from heart and spleen after norepinephrine-H³ injection was significantly inhibited by cocaine and desipramine but not by angiotensin. These data support the contention that norepinephrine-angiotensin interactions do not involve sympathetic nerve uptake mechanism(s).