Published online Apr 15, 2002. doi: 10.3748/wjg.v8.i2.350
Revised: January 13, 2002
Accepted: January 20, 2002
Published online: April 15, 2002
AIM: 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 °C), bubbled continuously with 950 mL•L⁻¹ O2 and 50 mL•L⁻¹ CO2. 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).
CONCLUSION: Areca stimulated the motility of isolated colonic smooth muscle strips in rats. The stimulation of areca might be relevant with M receptor partly.