Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 14, 2005; 11(6): 863-866
Published online Feb 14, 2005. doi: 10.3748/wjg.v11.i6.863
Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs
Ya-Li Luo, Jun-Wei Zeng, Mei Yu, Yu-Ling Wei, Song-Yi Qu, Wei Li, Tian-Zhen Zheng
Ya-Li Luo, Jun-Wei Zeng, Mei Yu, Song-Yi Qu, Wei Li, Tian-Zhen Zheng, Department of Physiology, Lanzhou Medical College, Lanzhou 730000, Gansu Province, China
Yu-Ling Wei, Drug Control Institute of Gansu Province, Lanzhou 730000, Gansu Province, China
Author contributions: All authors contributed equally to the work.
Supported by the Key Laboratory of Pre-clinical Research for Chinese Herbs and New Drugs of Gansu Province and The Natural Scientific Foundation of Gansu Province, No. zs021-A25-059-Y
Correspondence to: Tian-Zhen Zheng, Department of Physiology, Lanzhou Medical College, Lanzhou 730000, Gansu Province, China. wjztzl@126.com
Telephone: +86-931-8617647
Received: July 5, 2004
Revised: July 7, 2004
Accepted: July 15, 2004
Published online: February 14, 2005
Abstract

AIM: To investigate the effect of rhubarb on contractile response of isolated gallbladder muscle strips from guinea pigs and its mechanism.

METHODS: Guinea pigs were killed to remove the whole gallbladder. Two or three smooth muscle strips (8 mm×3 mm) were cut along the longitudinal direction. The mucosa on each strip was carefully removed. Each longitudinal muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution (37 °C), bubbled continuously with 950 mL/L O2 and 50 mL/L CO2. The resting tension (g), mean contractile amplitude (mm), and contractile frequency (waves/min) were simultaneously recorded on recorders. After 2-h equilibration, rhubarb (10, 20, 70, 200, 700, 1000 g/L) was added cumulatively to the tissue chamber in turns every 2 min to observe their effects on gallbladder. Antagonists were given 3 min before administration of rhubarb to investigate the possible mechanism.

RESULTS: Rhubarb increased the resting tension (from 0 to 0.40±0.02, P<0.001), and decreased the mean contractile amplitude (from 5.22±0.71 to 2.73±0.41, P<0.001). It also increased the contractile frequency of the gallbladder muscle strips in guinea pigs (from 4.09±0.46 to 6.08±0.35, P<0.001). The stimulation of rhubarb on the resting tension decreased from 3.98±0.22 to 1.58±0.12 by atropine (P<0.001), from3.98±0.22 to 2.09±0.19 by verapamil (P<0.001) and from 3.98±0.22 to 2.67±0.43 by phentolamine (P<0.005). But the effect was not inhibited by hexamethonium (P>0.05). In addition, the action of mean amplitude and frequency was not inhibited by the above antagonists.

CONCLUSION: Rhubarb can stimulate the motility of isolated gallbladder muscle strips from guinea pigs. The stimulation of rhubarb might be relevant with M receptor, Ca2+ channel and α receptor partly.

Keywords: Rhubarb; Gallbladder smooth muscle strips; M receptor; Ca2+ channel; α receptor