Effect of areca on contraction of colonic muscle strips in rats.
OBJECTIVE
To investigate the effects of areca on the contractile activity of isolated colonic muscle strips in rats and mechanism involved.


METHODS
Each strip (LMPC, longitudinal muscle of proximal colon; CMPC, circular muscle of proximal colon; LMDC, longitudinal muscle of distal colon; CMDC, circular muscle of distal colon.) was suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees C), bubbled continuously with 950 mL.L(-1) O(2) and 50 mL.L(-1) CO(2). The mean contractile amplitude (A), the resting tension (T), and the contractile frequency (F) were simultaneously recorded on recorders.


RESULTS
Areca dose dependently increased the mean contractile amplitude, the resting tension of proximal and distal colonic smooth muscle strips in rats (P<0.05). It also partly increased the contractile frequency of colonic smooth muscle strips in rats (P<0.05). The effects were partly inhibited by atropine (the resting tension of LMPC decreased from 0.44 +/- 0.12 to 0.17 +/- 0.03; the resting tension of LMDC decreased from 0.71 +/- 0.14 to 0.03 +/- 0.01; the mean contractile amplitude of LMPC increased from -45.8 +/- 7.2 to -30.5 +/- 2.9; the motility index of CMDC decreased from 86.6 +/- 17.3 to 32.8 +/- 9.3; P<0.05 vs areca), but the effects were not inhibited by hexamethonium (P>0.05).


CONCLUSIONS
Areca stimulated the motility of isolated colonic smooth muscle strips in rats. The stimulation of areca might be relevant with M receptor partly.
Xie
Dong-Ping
DP
Department of Physiology, Medical College, Shandong University, Jinan 250012, Shandong Province, China. xiedping@sdu.edu.cn
Li
Wei
W
Qu
Song-Yi
SY
Zheng
Tian-Zhen
TZ
Yang
Ying-Li
YL
Ding
Yong-Hui
YH
Wei
Yu-Ling
YL
Chen
Lian-Bi
LB
D000818:Animals; D001114:Areca; D001285:Atropine / Q000494:pharmacology; D003106:Colon / Q000187:drug effects* / Q000502:physiology; D005260:Female; D018738:Hexamethonium / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D010276:Parasympatholytics / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D018733:Nicotinic Antagonists; D010276:Parasympatholytics; D010936:Plant Extracts; D018738:Hexamethonium; D001285:Atropine