Published online Aug 15, 1998. doi: 10.3748/wjg.v4.i4.354
Revised: April 13, 1998
Accepted: May 9, 1998
Published online: August 15, 1998
AIM: To study the effects of Dangshen [dried root of Codonopsis Pilosula (Franch) Nannf] on contractile activity of isolated gastric muscle strips in rats and its possible mechanism involved.
METHODS: Each isolated gastric muscle strip was put in a tissue chamber containing 5 mL Krebs solution, constantly warmed by water jacket at 37 °C and supplied with a mixed gas of 95% O2 and 5% CO2. After incubating for 1 h with 1g tension, Dangshen of varied concentration was added cumulatively in the tissue chamber at intervals of 2 min. The isometrical response was measured on ink-writing recorders.
RESULTS: Dangshen dose dependence increased the resting tension of longitudinal muscle (LM) of fundus (r = 0.96, P < 0.01), the mean contractile amplitude of circular muscle (CM) of the stomach body (r = 0.87,P < 0.05) and CM of antrum (r = 0.98, P < 0.01), and the motility index CM of pylorus (r = 0.87, P < 0.05). Atropine (5 × 10-8 mol/L) or Hexamethonium (10-5 mol/L) or Indomethacin (5 × 10-7 mol/L) was given 2 min before the administration of Dangshen, it did not abolish its dose related manner. Atropine apparently reduced the increasing action of 10% and 30% Dangshen on the resting tesion of LM of fundus (P < 0.05), 30%, 100% and 200% Dangshen on bodied strips (P < 0.05), 100% and 200% Dangshen on antral strips (P < 0.05).Hexamethonium reduced the increasing action of 10% and 30% Dangshen on the resting tesion of LM of fundus (P < 0.05 and P < 0.05), 30%, 100% and 200% Dangshen on bodied strips (P < 0.05), and 100% and 200% Dangshen on pyloric strips (P < 0.05). Indomethacin inhibited the effect of 10% Dangshen on the resting tesion of LM of fundus (P < 0.05), but did not affect the exciting action of Dangshen on strips of body, antrum and pylorus.
CONCLUSION: The results showed that Dangshen possessed exciting action on the isolated gastric smooth muscle strips of the rat. The exciting action of Dangshen was partially mediated via cholinergic M and N receptors.