N-(2-CHLOROETHYL)-N-ETHYL-2-BROMOBENZYLAMINE (DSP4) IMPAIRS NEUROTRANSMISSION IN THE VAS-DEFERENS OF THE RAT

1. The in vitro effects of N-(2-chloroethyl)-N-ethyl-bromobenzylamine (DSP4) were studied in the rat vas deferens. 2. DSP4 inhibited the bip hasic motor response induced by field stimulation in a concentration-d ependent manner. The concentration of DSP4 that elicited 50% of the ma ximal inhibition of the twitch response induced by 3 Hz was 10 muM. 3. DSP4 10 muM abolished the motor response induced by exogenously appli ed noradrenaline and 0.1 mM ATP. Phentolamine (an alpha-adrenoceptor b locker) prevented DSP4 inhibitory effect. 4. DSP4 inhibitory effect wa s no due to the activation of alpha2-presynaptic adrenoceptor mechanis ms. 5. DSP4 impairs neurotransmission in the rat vas deferens by a pos tsynaptic alpha1-adrenoceptor blockade and by an inhibition of the pur inergic response.