The effects of jatrorrhizine on contractile responses of rat ileum.

This study was designed to evaluate the effect of jatrorrhizine on smooth muscle contractions isolated from rat ileum longitudinal muscles. Jatrorrhizine increased the amplitude of spontaneous contractions of ileum longitudinal muscles in concentration-dependent manner with an EC(50) of 30.0±8.4μM. Preincubation of ileum strips with atropine (1μM), 4-diphenyllacetoxy-N (2-chloriethyl)-piperidine (4-DAMP, 1μM) or darifenacin (1μM) significantly inhibited acetylcholine (0.1μM)- and jatrorrhizine (100μM)-induced ileum longitudinal muscle contractions, whereas they were not affected by AF-DX116 (1μM) or hexamethonium (100μM). Pretreatment with SB204070 (1μM) rather than 3-tropanyl-indole-3-carboxyleat (tropisetron, 1μM) significantly inhibited 5-HT (10μM)-induced ileum longitudinal muscle contractions. In contrast, jatrorrhizine-induced ileum longitudinal muscle contractions were not inhibited by tropisetron or SB204070. Furthermore, jatrorrhizine-induced ileum longitudinal muscle contractions were strongly inhibited by nifedipine (1μM), and also attenuated by removal of extracellular Ca(2+), U73122 (1μM), ruthenium red (50μM) or 2-aminoethoxydiphenylborate (2-APB, 10μM). Taken together, jatrorrhizine-elicited spontaneous contractions in rat ileum longitudinal muscles are mediated by activation of acetylcholine receptors, mostly the M(3) receptor. Ca(2+) influx through L-type Ca(2+) channel is significantly contributed to jatrorrhizine-elicited spontaneous contractions, and Ca(2+) release via IP(3) and ryanodine pathways are also involved. Copyright © 2011. Published by Elsevier B.V.

Citation

JianYe Yuan, JiYan Zhou, ZhiBi Hu, Guang Ji, JianQun Xie, DaZheng Wu. The effects of jatrorrhizine on contractile responses of rat ileum. European journal of pharmacology. 2011 Aug 1;663(1-3):74-9

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PMID: 21596029

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