Effects of Acupuncture on Gastric Motility in Rats

描述(申请人提供)：中国使用针灸治疗胃肠道症状已有3000多年的历史。然而，针灸的疗效机制尚不清楚。我们最近的研究表明，在硫代丁巴比妥(Inactin)麻醉的大鼠中，腹部针刺引起一过性胃松弛，而后肢针刺引起一过性收缩。异丙肾上腺素、心得安、六甲胺、内脏神经节切除术可消除针刺腹部引起的胃松弛作用，但不能切断迷走神经。相反，阿托品、六甲胺和迷走神经切断术可取消针刺后肢引起的胃收缩，而内脏神经节切除和乙双胍则不起作用。针刺引起的胃收缩和舒缩均可被切断脊髓延髓而取消，但不能被切断延髓桥取消，提示针刺引起的胃收缩和舒缩是通过脑干调节的。提示针刺引起的胃舒缩分别通过躯体-交感神经通路和躯体-副交感神经通路介导。我们将研究针刺后肢是否刺激迷走神经背侧运动核(DMV)的c-Fos表达、迷走神经传出神经活动和胃壁ACh的释放。中国教授曾用足穴针刺治疗厌食症及术后肠梗阻。我们的初步研究表明，针刺后肢可增强清醒大鼠的胃收缩，加速固体胃排空。已有研究证明糖尿病大鼠胃排空延迟，而胃排空延迟的原因可能是迷走神经张力受损。我们将研究针灸是否能改善糖尿病大鼠胃排空障碍。虽然术后肠梗阻的机制仍不清楚，但迷走神经张力降低和交感神经张力增加的可能性已经被提出。我们将研究针刺是否能缩短大鼠术后肠梗阻的时间。本研究将为胃瘫和术后肠梗阻患者提供有益的信息。

DESCRIPTION (provided by applicant): Acupuncture has been used to treat gastrointestinal (GI) symptoms in China for more than 3,000 years. However, the mechanism of beneficial effects of acupuncture still remains unknown. Our recent studies have shown that acupuncture to the abdomen caused a transient relaxation of the stomach, while the acupuncture to the hind limb caused a transient contraction in thiobutabarbital (Inactin)-anesthetized rats. Gastric relaxations induced by acupuncture to the abdomen were abolished by guanethidine, propranolol, hexamethonium, splanchnic ganglenectomy, but not by vagotomy. In contrast, gastric contractions induced by acupuncture to the hind limb were abolished by atropine, hexamethonium and vagotomy, while splanchnic ganglenectomy and guanethidine had no effects. Both of acupuncture-induced gastric relaxations and contractions were abolished by spino-medullary transection, but not by pontomedullary transection, suggesting the mediation via the brain stem. It is suggested that gastric relaxations and contractions induced by acupuncture are mediated via the somato-sympathetic and somato-parasympathetic neural pathway, respectively. We will study whether acupuncture to the hind limb stimulates c-Fos expression at the dorsal motor nucleus of vagi (DMV), neural activity of vagal efferent and ACh release from the gastric wall. Acupuncture of the lower extremity has been used to treat the patients with anorexia and postoperative ileus in China. Our preliminary study demonstrated that acupuncture to the hind limb potentiates gastric contractions and accelerates solid gastric emptying in conscious rats. It has been demonstrated that gastric emptying is delayed in diabetic rats and that the origin of the delayed gastric emptying was implied to be because of impaired vagal tone. We will study whether acupuncture improves impaired gastric emptying in diabetic rats. Although the mechanism of postoperative ileus still remains unclear, the possibility of reduced vagal tone and increased sympathetic tone has been suggested. We will study whether acupuncture shortens the period of postoperative ileus in rats. This study would provide beneficial information for patients with gastroparesis and postoperative ileus.