Abstract:

Objective：To observe the effect of ethyl acetate extracts from Geranium strictipes R. Knuth on the isolated guinea-pig
ileum smooth muscle, and to explore the mechanism of its in vitro action. Methods：The normal contraction curve was observed after
the isolated ileum specimens were prepared. Then contraction in smooth muscle caused by Geranium strictipes R. Knuth and three
blockers was recorded. Results：The Geranium strictipes R. Knuth in different doses could accelerate the ileum smooth muscle
contraction of the guinea-pig. The maximum tension, frequency and amplitude induced by 20 and 40 mg/mL extracts had a statistical
difference（P < 0.01）compared with the normal group; and it could resist against ileum smooth muscle relaxation induced by Atropine
and Chlorobenzene. Conclusion：The Geranium strictipes R. Knuth has stimulating effects on ileum smooth muscle extraction of the
guinea-pig, and the contractile effect may be related to M receptor and H1 receptor.

Key words: Geranium strictipes R. Knuth, isolated ileum, M receptor, H1 receptor