Role of Vagal nerve in Airway Hyperresponsiveness.

迷走神经在气道高反应性中的作用。

基本信息

批准号：
01570432
负责人：
AIZAWA Hisamichi
金额：
$ 1.41万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

Although the importance of the vagal nerve in the pathogenesis of bronchial asthma has been reported, its precise contribution is still not fully understood. To shed more light on this area, we performed the following experiments.First, we evaluated the possible contribution of vagal reflex in Histamine-Induced Bronchoconstriction (HIB), and decided the site of action of histamine on the vagal nerve. For this purpose, we studied the effects of the bilateral cervical vagotomy, hexamethonium (2 mg/kg) or tetrodotox in (0.5 mg/kg) on HIB (8 mug/kg, iv) in anesthetized and mechanically ventilated guinea pigs. We also studied whether or not atropine (1 mg/kg) decreases HIB after vagotomy, including either the treatment of hexamethonium or tetrodotoxin.The following results were obtained ; 1) The response to histamine was significantly enhanced by the vagotomy, hexamethonium or tetrodotoxin. 2) Propranolol increased HIB and HIB was further enhanced by the vagotomy in the animals treated with … More propranolol. 3) Atropine significantly suppressed HIB after the vagotomy, hexamethonium or tetrodotoxin. These results suggest that the postganglionic vagus nerve plays an excitatory role in HIB through the release of acetylcholine from the nerve terminals. It is also suggested that the vagal reflex mainly exhibits an inhibitory role in the HIB of guinea pigs, presumably by theSecond, to elucidate whether the local reflex may release tachykinin, we studied the effects of atropine (10^<-6> M), tetrodotoxin (TTX) (10^<-7> M) on the bradykinin induced contraction of guinea pig Tracheal Smooth Muscle (TSM) in vitro, with or without capsaicin pretreatment. Atropine did not change the contraction induced by bradykinin in the control animals. TTX suppressed bradykinin-induced contraction. Neither atropine nor TTX did affect bradykinin-induced contraction of TSM in the animals with capsaicin pretreatment.These results indicated that bradykinin may cause a local neurally mediated action in TSM contraction, without release of acetylcholine from efferent vagal nerve terminals, presumably by the release of tachykinins from vagal efferent endings through axon reflex. Less

尽管已经报道了迷走神经在支气管哮喘发病机理中的重要性，但其精度贡献仍未完全了解。为了更多地了解该区域，我们进行了以下实验。首先，我们评估了迷走神经反射在组胺引起的支气管收缩（HIB）中的可能贡献，并决定了组胺对迷走神经的作用部位。为此，我们研究了双侧宫颈迷走术，六甲基甲基盐（2 mg/kg）或四局毒素（0.5 mg/kg）对麻醉和机械频静脉毒猪的HIB（8 mug/kg，iv）的影响。我们还研究了阿托品（1 mg/kg）在迷走神经切开术后是否会降低HIB，包括治疗六甲基或四毒素。获得以下结果； 1）通过迷走术，六甲基或四毒素的反应显着增强了对组胺的反应。 2）普萘洛尔增加了hib和hib，并通过……更多普萘洛尔治疗的动物的迷走神经切开术进一步增强。 3）阿托品在迷走神经切开术，六甲基或四毒素后显着抑制了HIB。这些结果表明，通过从神经末端释放乙酰胆碱，gangionic迷走神经在HIB中起着令人兴奋的作用。 It is also suggested that the vagal reflex mainly exhibits an inhibitory role in the HIB of guinea pigs, presumably by the Second, to elucidate whether the local reflex may release tachykinin, we studied the effects of aromapine (10^<-6> M), tetrodotoxin (TTX) (10^<-7> M) on the bradykinin induced contraction of guinea pig Tracheal Smooth Muscle （TSM）体外，有或没有辣椒素预处理。阿托品没有改变对照动物中蓬金引起的收缩。 TTX抑制了心动激肽诱导的收缩。阿托品和TTX都没有影响辣椒素预处理动物中铁蛋白诱导的TSM收缩。这些结果表明，在没有有效的迷走神经末端释放乙酰胆碱的情况下，缓激肽可能会在TSM合同中引起局部中性中性介导的作用，这大概是通过通过轴突反射从迷走神经末端释放了tachykinins。较少的