EFFECT OF FEDOTOZINE ON HUMAN DISTAL COLON

Fedotozine was tested in colonic strips removed during surgery from pa tients suffering from different diseases of the colon; the effects wer e compared to those of morphine and of the k selective opiate agonist U-69593, Fedotozine did not affect the spontaneous motility of human c olonic strips, unless very high concentrations were used, Fedotozine ( 10(-6)-3x10(-4) M) induced a concentration-dependent reduction of the excitatory effect induced by field stimulation, an effect which was pa rtially mimicked by compound U-69593 and by morphine but not inhibited by naloxone, The cumulative dose-response curve to nous acetylcholine was inhibited by fedotozine (3x10(-4) M), whereas morphine had no eff ect up to 3x10(-4) M. In colonic strips incubated with [H-3]-choline, fedotozine (10(-5)-10(-4) M) induced an erratic decrease of acetylchol ine-release induced by electric stimulation, In our experimental model , the inhibitory effect of fedotozine does not seem to be related to o pioid receptor activation.