Abstract:

Objective: To observe the spasmolytic action of different polar parts of Pinus yunnanensis on trachea in vitro of guinea
pigs in different state. Methods: Using the methods of trachea in vitro, the influence of different polar parts of P. yunnanensis on
trachea in vitro in resting state and acetylcholine（Ach）or histamine（His）induced spasm state were observed. Results: Ethanol
extract, petroleum ether and chloroform parts of P. yunnanensis can reduce the tension of trachea in vitro in resting state and
significantly increase basic spasmolysis rate; Ethanol extract, petroleum ether, chloroform and ethyl acetate parts of P. yunnanensis can
reduce the tension of trachea in vitro in the Ach, His induced spasm state and significantly increase spasmolysis rate of spasmodic
trachea. Conclusion: Ethanol extract, petroleum ether and chloroform part of P. yunnanensis can improve the spasmolysis rate of
trachea in vitro of guinea pigs in different state, and relax resting and spasmodic trachea.

Key words: Pinus yunnanensis, trachea in vitro, spasmolytic effect