2004 年 25 巻 3 号 p. 125-132
The aim of the present study was to investigate the effect of lipopolysaccharide (LPS) and (−)-epigallocatechin-3-gallate (EGCg) on motility of jejunal segments isolated from mice. Endotoxemia, induced by intraperitoneal injection of 10 mg/kg LPS, evoked a significant decrease in the amplitude of spontaneous isometric contractions and an increase in the papaverine-induced relaxations. EGCg induced a dose-dependent relaxation and a decrease in the amplitude and the rate of spontaneous contractions. The effect was observed at relatively low concentration of EGCg (0.125 mM) and was not inhibited by naloxone, phentolamine, or yohimbine. The response to acetylcholine in the presence of EGCg was bigger in endotoxemic animals. Naloxone enhanced the acetylcholine-induced contractions in the presence of EGCg in saline-treated animals, while in endotoxemic animals it was not effective. In conclusion, endotoxemia induces an impairment of spontaneous jejunal contractions recorded in vitro. The EGCg-induced relaxations are smaller in endotoxemic tissues and do not depend on alpha adrenergic and opioid receptors. Additionally, an EGCg-induced increase in the acetylcholine-evoked contractions in endotoxemic animals suggests that EGCg may have a positive effect on LPS-induced impairment in intestinal motility.