This is the first time that the mechanical activity of Hedgehog i leal

smooth muscle is a regular spontaneous contraction to be reported. It was  found  that  the different concent1·ations of  papaverine exerted different dcgces of inhibition on ileal smooth muscle. The minimum

effective  dose  was  (0.05)  mM.  Different  concentration  of acetylcholine and KCI caused tonic contraction in this kind of smooth muscle. High concentration of papaverine caused inst<mt relaxation in acetylcholine or Kcl- excited muscle. The inhibitory effect of the drug resul ted from the reduction of the available  free calcium and caused relaxation.