A SIMPLE, RAPID HPLC METHOD FOR THE CONCURRENT MEASUREMENT OF COCAINEAND CATECHOLAMINES IN BRAIN-TISSUE SAMPLES

We describe a simplified HPLC method for the measurement of cocaine an d catecholamines in the same brain tissue sample. Using this method to measure cocaine in the brain of rats which received either 10 or 20 m g/kg cocaine injections, we found substantial cocaine concentration di fferences between medial prefrontal cortex, striatum and limbic brain areas. Specifically, for each cocaine dose level there was a nearly 2- fold differential between cocaine concentration in the cortex as compa red to limbic tissue. A shortcoming of many neurobehavioral studies of cocaine effects is the absence of brain cocaine measurements. The sim plicity of the present method makes the measurement of cocaine and cat echolamines from the same tissue sample a procedure which can readily be incorporated in the studies designed to evaluate the neurochemical effects of cocaine treatments.