AN INVESTIGATION OF THE MECHANISM OF POTENTIATION BY COCAINE OF RESPONSES TO SEROTONIN IN SHEEP UMBILICAL BLOOD VESSELS

¹ Department of Pharmacology, School of Medicine, University of Washington, Seattle, Washington

Cocaine was found to cause a dose-dependent potentiation of contractions to serotonin on sheep umbilical arteries. During the potentiation period there was a decrease in the uptake of H³-serotonin. Metabolic inhibitors such as dinitrophenol, potassium cyanide and nitrogen atmosphere did not cause a significant decrease in serotonin uptake, whereas incubation at 0°C did reduce the uptake. Desmethylimipramine and cocaine produced dosedependent reductions of H³-serotonin uptake in umbilical vein. The combination of cocaine and desmethylimipramine produced no greater reduction in uptake of H³-serotonin than either alone. Desmethylimipramine did not potentiate responses to serotonin probably because its inhibition of uptake was counterbalanced by an antagonistic action.

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				L. Zhang and X.-Q. Hu Endothelium-Dependent Potentiation by Cocaine of Serotonin-Induced Contractions in Sheep Fetal Umbilical Artery Reproductive Sciences, March 1, 1998; 5(2): 72 - 74. [Abstract] [PDF]