The Action Of Pinaverium Bromide On Transverse Colon Ex Vivo Strips Of Human

Objectives: To investigate the effect of pinaverium bromide, an L-type calcium channel blocker on the contractile activity of isolated circular muscular strips and longitudinal muscular strips in human transverse colon, and to observe the effect of pinaverium bromide on the contraction of strips, which is induced by Ach. Methods: 1.Normal tissues of the human transverse colon were collected from the left hemicolon carcinoma surgery. Circular muscular strips and longitudinal muscular strips were made, and were placed in homeothermal perfusion bath full of Krebs solution. One end of the strips was tied in a tissue chamber while the other end was connected to an isometric force transducer. Pinaverium bromide of different concentrations was added into the chamber and the motility of strips was recorded. 2.The contraction of strips was induced by acetylcholine at first, and then pinaverium bromide of different concentrations was added into the chamber and the motility of strips was recorded. Results: 1.The suppressive effect of pinaverium bromide at different concentration levels on the contraction of circular strips were 0.74%, 11.7%, 28.19%, 63.62%, 75.12% and 93.02% respectively. Pinaverium bromide of 10^-10 mol/L did not suppress the contraction of circular strips evidently, but that of 10^-9mol/L demonstrated a good inhibitory action on the contration of circular strips of human transverse colon (p<0.05). 2. The suppressive effect of pinaverium bromide of different concentrations on the contraction of longitudinal strips were 0.24%, 23.59%, 63.14%, 86.07% and 95.34% respectively. Pinaverium bromide of 10^-9mol/L can relax the longitudinal strips of human transverse colon markedly (p<0.05). 3. When added with acetylcholine, the wave amplitude of the contraction of human transverse colon strips increased. The pinaverium bromide showed a dose-dependent suppressive effect on the contraction of smooth muscle strips of human transverse colon induced by acetylcholine (p<0.05). Conclusions: Pinaverium bromide can suppress the contractile activity of human transverse colon and it can antagonize the action of acetylcholine, both of which are in dose-dependent manner.