Evidence from desensitization studies for distinct receptors for ATP and UTP on the rat superior cervical ganglion

Abstract

Prolonged contact of the rat superior cervical ganglia (SCG) with the purine alpha,beta-methylene-ATP (alpha,beta-Me-ATP) selectively depressed responses to ATP and alpha,beta-Me-ATP but not responses to uridine 5'-triphosphate (UTP), potassium or adenosine. Prolonged contact with the pyrimidine UTP selectively depressed responses to UTP but not responses evoked by alpha,beta-Me-ATP, potassium or adenosine. These results are consistent with the presence of P2-purinoceptors and pyrimidinoceptors on the rat SCG and the hypothesis that pyrimidinoceptors exist within the nervous system.