Abstract: Aim To investigate the effects of 1-(2, 6-dimethy lphenoxy)-2-(3, 4-dime thox ypheny-lethy lamino)pro pane hydrochloride (DDPH)on cont raction of isolated ileum of guinea pigs induced by some mediators.Methods The routine methods for experiment on contraction-effect of the isolated ileum were emplayed.Results Histamine, acetyl choline and CaCl₂ separetely caused a significant cumulative concentration-related effect on ileum constraction with the pD₂ values being 7.7、9.8 and 5.3 respectively.after being incubated with DDPH of different dosage for 15 min, the responses elicited by Hist.ACh and CaCl₂ were depressed and the pD₂'values were 4.0, 3.8 and 3.9 respectively.Cumulative concent ration of DDPH and verapamil Resulted in a concentration dependent relaxing effect on contraction of ileum induced by K⁺ 60 mmol·L^-1 with the IC₅₀ values being 2.7 μmol·L^-1 and 0.7 μmol·L^-1. Conclusion DDPH has significant relaxing effect and a calcium antagonistic effect on ileum.

Key words: DDPH, verapamile, histamine, acetylcholine, calcium chloride, ileum