CARDIOVASCULAR AND HEMODYNAMIC-EFFECTS OF COCAINE IN THE RAT

The interrelationship between central and peripheral components to the sympathomimetic effects of cocaine are not well understood. The objec tive of this study was to further examine the cardiovascular and sympa thetic responses to cocaine in conscious and pithed rats. We also eval uated the regional hemodynamic effects of cocaine in anesthetized rats . Cocaine significantly increased blood pressure (BP) and heart rate ( HR) in the conscious rats. The pressor as well as the (HR) response to cocaine were reduced in adrenaldemedullated (ADMX) rats. In the pithe d rat, a dose-dependent pressor and bradycardic responses were observe d after cocaine. In the anesthetized rat, cocaine caused hypotension a nd bradycardia in most cases. The hemodynamic effects of cocaine are n ot uniform in all vascular beds. Aortic blood flow was greatly enhance d especially with the higher doses used. Cocaine significantly decreas ed renal blood flow. Thus cocaine may cause renal ischemia secondary t o intense vasoconstriction of the renal vasculature.