| The resources of Urtica are rich in xinjiang, especially Urtica Cannabina(UC) and Urtica Angustifolia(UA) the most widely distributed. To explore whether Urtica can influence the activity of smooth muscle, effects of UC and UA on the contractile activity of rat small intestine and uterus were compared. This study used the receptor or ion channel blockers strategy to investigate their possible mechanisms and have hope to providing reference for the Urtica can treat gastrointestinal and uterine motility disorders.First, effect of alcohol extract of UC or UA with increasing concentrations on the motility of non-pregnant rats uterine smooth muscle strips using biological signal processing system. The results showed that when the concentration of UC arrived 4.0% significantly increased the frequency of uterine contraction compared with before treatment(P<0.05); arrived 4.0%~8.0%,significantly reduced contraction amplitude compared with before treatment, but the tension was not obvious impact. Concentration of UA at 0.5%, uterine contraction was suppressed, but when the concentration arrived 2.0%, the uterine contraction tension increased, speeded up the frequency; when the concentration arrived 8.0%, the uterus appeared to stiffness and tension gradually decreased, until it was completely suppressed. UC(2.0%) and M-receptor antagonist atropine(6.2×10-6 mol/L) combination treatment, uterine contraction frequency was significantly accelerated compared with before treatment, contraction tension increased(P<0.05), but lower than the UC alone treatment(P> 0.05).Secondly, effect of alcohol extract of UC or UA with increasing concentrations on the motility of intestinal smooth muscle was explored in rats. The results showed that when the concentration of UC arrived 2.0%, the contraction frequency, tension and amplitude were increased; when arrived 4.0%~8.0%, the contraction frequency and contraction amplitude were significantly lower than before treatment(P<0.05). Concentration of UA at 0.5% intestine showed short stiff trend, then with increasing concentrations of UA, the contraction tension and amplitude were increased; however, when the concentration arrived 2.0%~4.0%, the motility of intestine appeared inhibition. When verapamil(the calcium channel blockers, 2×10-7mol/L,) and UC(2.0%)combined, the contraction tension, amplitude and frequency of intestine were significantly inhibited compared with those before treatment or UC alone(P< 0.05). The motility of intestine was not significantly changed by UC combined with phentolamine, ranitidine, diphenhydramine or indomethacin, compared with UC alone(P> 0.05).Finally, effect of UC on the gastric emptying rate and intestinal propulsion rate in fasted mice was explored. The results showed that gastric emptying rates were more than 95% by each concentration(0.4%, 2.0% and 10.0%) of UC, saline(blank) and bethanechol(the positive control), and there were no significant difference(P>0.05) between the treatments. Intestinal propulsion rates were significantly increased by each concentration of UC and bethanechol compared with the saline treatment(P<0.05); Intestinal propulsive rate was significantly reduced by atropine alone compared with 0.4% UC combination(P<0.05), intestinal propulsive rates were decreased by them compared with saline treatment(P<0.05).The results of the study indicated that UC stimulated the motility of uterus and intestine smooth muscle at a dose-dependent manner in rats; however, UA showed two different effects,inhibition or excitation, at different concentrations. The excitatory effect of UC on gastrointestinal and uterine smooth muscle may mediated by M- receptors and/or calcium channels. The Urtica is expected for the treatment of gastrointestinal and uterus related motility disorder diseases. |
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