MODULATION BY PROSTAGLANDIN-E2 OF ATP AND NORADRENALINE COTRANSMISSION IN THE GUINEA-PIG VAS-DEFERENS

1 In the guinea-pig vas deferens, prostaglandin E2 (100 nM) enhanced the overflow of ATP, whereas it inhibited [H-3]-noradrenaline overflow due to field stimulation at 2 Hz. At 20 Hz, prostaglandin E2 still inhibited the overflow of [H-3]-noradrenaline, whereas it was without effect on ATP overflow. 2 Prostaglandin E2 enhanced contractions to exogenously added noradrenaline and alpha, beta-methylene ATP. 3 These results provide evidence for pre- and postjunctional modulation of purinergic and adrenergic transmission by PGE2 in the guinea-pig vas deferens. The importance of these findings in relation to co-transmission is discussed.