Effects of Dangshen on isolated gastric muscle strips in rats

Abstract

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 5ml Krebs solution, constantly warmed by water jacket at 37?mgr; and supplied with a mixed gas of 95% O(2) and 5% CO(2). After incubating for 1h with 1g tension, Dangshen of varied concentration was added cumulatively in the tissue chamber at intervals of 2 minutes. 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 minutes 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.

Figure 1

Effect of Dangshen and antagonists plus Dangshen on the mean contractile amplitude of bodied strips in rats. ^aP < 0.05, ^bP < 0.01 vs control; ^cP < 0.05 vs Dangshen in the same concentration; ^-x ± s_x (%) increase.

Figure 2

Effect of Dangshen and antagonists plus Dangshen on the mean contractile amplitude of antral strips in rats. ^aP < 0.05, ^bP < 0.01 vs control; ^dP < 0.01 vs Dangshen on same concentration; ^-x ± s_x (%) increase.

Figure 3

Effect of Dangshen and antagonists plus Dangshen on the mean contractile amplitude of pyloric strips in rats. ^aP < 0.05, ^aP < 0.05, ^bP < 0.01 vs control; ^dP < 0.01 vs Dangshen on same concentration; ^-x ± s_x (%) increase.