Cardiovascular Complications following Chronic Treatment with Cocaine and Testosterone in Adolescent Rats

Abstract

Concomitant use of anabolic androgenic steroids and cocaine has increased in the last years. However, the effects of chronic exposure to these substances during adolescence on cardiovascular function are unknown. Here, we investigated the effects of treatment for 10 consecutive days with testosterone and cocaine alone or in combination on basal cardiovascular parameters, baroreflex activity, hemodynamic responses to vasoactive agents, and cardiac morphology in adolescent rats. Administration of testosterone alone increased arterial pressure, reduced heart rate (HR), and exacerbated the tachycardiac baroreflex response. Cocaine-treated animals showed resting bradycardia without changes in arterial pressure and baroreflex activity. Combined treatment with testosterone and cocaine did not affect baseline arterial pressure and HR, but reduced baroreflex-mediated tachycardia. None of the treatments affected arterial pressure response to either vasoconstrictor or vasodilator agents. Also, heart to body ratio and left and right ventricular wall thickness were not modified by drug treatments. However, histological analysis of left ventricular sections of animals subjected to treatment with testosterone and cocaine alone and combined showed a greater spacing between cardiac muscle fibers, dilated blood vessels, and fibrosis. These data show important cardiovascular changes following treatment with testosterone in adolescent rats. However, the results suggest that exposure to cocaine alone or combined with testosterone during adolescence minimally affect cardiovascular function.