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Objective To investigate the constituents of water and ethanol extracts from the stems and leaves ofAucklandia lappa and their effect on gastric emptying and intestinal propulsion of gastrointestinal normal,hyperthyroidism and inhibited mice.Methods The water,ethanol and aether petrolei extracts from stems and leaves of A.lappa were prepared,and the chemical constituents of the stems and leaves were identified by chemical reaction.The hyperthyroidism state was induced by neostigmine and inhibiting state was induced by atropine.Mice were ig administered with water and ethanol extracts (0.5 g/kg),with the improved phenol red method to determine gastric emptying and intestinal propulsion in gastrointestinal normal,hyperthyroidism and inhibited mice.Results Both water and ethanol extracts significantly improved intestinal propulsion in normal mice (P < 0.05 and 0.01),while significantly decreased the intestinal propulsion in hyperthyroidism mice (P < 0.05) and ethanol extract showed a stronger decreasing effect than that of water extract.The inhibitory effect of atropine on intestinal propulsion was intensified by these two extracts (P < 0.05).The restrained gastric emptying of normal,hyperthyroidism and inhibited mice was also observed.Chemical composition analysis indicated that many kinds of chemical components including protein,sugar,essential oil,flavonoids,lactones,alkaloids,saponins and tannins existed in the leaves and stems of A.lappa.Conclusion The leaves and stems of A.lappa could promote the intestinal propulsion of normal mice and restrain the intestinal propulsion of hyperthyroidism and inhibited mice while inhibit the gastric emptying in any condition tested,and its promoting effect on the gut may be related to the M cholinergic receptor.
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Protective effect and mechanism of electroacupuncture (EA) on acute reperfusion ventricular arrhthmia was investigated. Ventricular arrhythmia was induced by occlusion of the proximal left anterior descend (LAD) branch of coronary artery for 5 min and followed with 15 min reperfusion . EA on acupoint "Neiguan", "Jianshi" was performed at 30 min before ligation and continued another 5 min during ischemia. Isoprenaline (20, 30 and 50 μg/kg) or atropine (1 mg/kg) was intravenously injected at 5min before ischemia. The results showed that EA significantly decreased the incidence of ischemia/reperfusion (I/R) induced ventricular tachycardia (VT), ventricular fibrillation (VF) and mortality as compared to I/R group. Atropine partially suppressed the EA's effect of antiarrhythmia; Isoprenaline increased the incidence and severity of reperfusion arrhythmia, which was inhibited by EA, but this inhibition of EA was blocked with increasing dose of isoprenaline. The results indicated that EA treatment could prevent the occurrence of reperfusion ventricular arrhythmia in rats with myocardial ischemia, and its mechanism might be related to the regulation of EA on the β-adrenoceptors and M-cholinergic receptor activation in myocardium.
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Objective To investigate whether catalpol is the active component responsible for the Yin tonic effect of Radix Rehmanniae.Methods Young NH mice were injected with triiodothyronine to produce the hyperthyroidism model,while old mice were used as the model of natural aging.The single point radioligand binding assay was carried out to determine the ?-adrenergic receptor density and M-cholinergic receptor density.The learning ability(short term memory) was determined by the Y-maze avoidance test. Results In the ?-adrenergic receptor experiment,the densities were(15.7?5.2) and(20.9?7.2) fmol/mg protein in normal control group and in T3 control group(P
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Aim To observe the effect of taurine on learning-memory ability and its mechanism in model mice induced by scopolamine(Scop). Methods Kunming mice were randomly divided into normal control group, Scop model group, taurine groups (0.3, 0.75, 1.875 g?kg -1) and Piracetam group (positive control group). The drugs were continually intra-gastrically administrated for 5 days. On day 5, after intraperitoneal injection of scopolamine, mice were subjected to Morris water maze test. 5 days later, M-cholinregic receptor binding was assayed by radio ligand binding test.Results Compared with model group, significant decrease of swimming time and distance in Morris water maze test was observed in all 3 taurine groups. Taurine at middle dose increased M-cholinergic receptor binding in the brain of model mice. Conclusion Taurine effectively improves learning-memory ability in model mice induced by scopolamine injection. The mechanism relates with the improvement of M-cholinergic receptors of brain.