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ESOPHAGO-LARYNGEAL ADDUCTOR REFLEX

食管-喉内收肌反射

基本信息

批准号：
6175641
负责人：
Nancy Marie Bauman
金额：
$ 12.37万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-09-01 至 2002-08-31
项目状态：
已结题

项目摘要

Stimulation of distal esophageal afferent neurons with 0.5% capsaicin in immature canines elicits an intense response referred to as the Esophago- Laryngeal Adductor Reflex (ELAR). The ELAR is characterized by hypertension, tachycardia and intense vocal cord adduction which progresses to laryngospasm. The ELAR demonstrates a unique age-dependency that bears important similarities with the age predisposition of apparent life-threatening events, and sudden infant death syndrome. The ELAR is absent in canines under 6 weeks of age, peaks in intensity between 7-19 weeks of age, and wanes with maturity. Previous studies have suggested that substance P is a key neurotransmitter of the ELAR and that the efferent limb of the response is vagally mediated. The afferent limb and the role of the central nervous system in the ELAR are unknown. This proposal further investigates the ELAR in immature canines. The specific objectives of the proposal are: 1. To characterize the response of the airway of immature canines to distal esophageal afferent stimulation. 2. To assess the effect of maturation on the cardiorespiratory and laryngeal responses of distal esophageal nociceptive stimulation 3. To elucidate the afferent neural pathway of the ELAR. 4. To determine the role of the central vagal nuclei in mediating the ELAR. 5. To determine if esophageal acidification induces the ELAR in immature canines with acute esophagitis. These specific aims will be explored in immature canines by applying 0.5% capsaicin to the distal esophageal mucosa to elicit an ELAR. The airway response of the ELAR (bronchoconstriction, change in respiratory rate, and laryngeal adduction) will be assessed. Esophageal stimulation with 0.5% capsaicin will be repeated every 3 weeks in 6 week old puppies for 15 weeks to characterize the effect of maturation on the intensity of the ELAR response. Transection and denuding studies will clarify the role of the vagus nerve in mediating the afferent limb of the ELAR. The role of the central vagal nuclei in mediating the ELAR will be assessed by comparing the response to distal esophageal nociceptive stimulation with capsaicin before and after chemically antagonizing their substance P NK1 receptors. Finally, the cardiorespiratory response following distal esophageal acidification of an acutely inflamed esophagus will be compared with the ELAR elicited by 0.5% capsaicin stimulation.

用0.5%辣椒素刺激食管远端传入神经元未成熟的犬齿会产生强烈的反应，称为食道，喉内收肌反射（ELAR）。ELAR的特点是高血压、心动过速和声带内收，发展为喉痉挛。 ELAR显示了一种独特的年龄依赖性，与明显危及生命的年龄倾向相似婴儿猝死综合症（Sudden Infant Death Syndrome）ELAR在犬中缺失 6周龄以下，在7-19周龄之间达到强度峰值，随着成熟而衰退。以前的研究表明，P物质是一个关键神经递质的ELAR和传出肢体的反应是迷走神经介导的传入肢和中枢的作用 ELAR的神经系统是未知的。该建议进一步研究了未成熟犬的ELAR。的该提案的具体目标是： 1. 为了表征未成熟犬气道对远端食管传入刺激。 2. 评估成熟对心肺功能的影响，食管远端伤害性刺激的喉反应 3. 阐明ELAR的传入神经通路。 4. 为了确定迷走神经中枢核团在介导脑电活动中的作用， ELAR。 5. 为了确定食管酸化是否诱导未成熟的ELAR，患有急性食管炎的犬。将在未成熟犬中探索这些特定目的，将辣椒素注射到远端食管粘膜以引起ELAR。气道 ELAR的反应（支气管收缩，呼吸频率的变化， ”““对，““将被评估。食管刺激， 0.5%辣椒素将每3周在6周龄幼犬中重复， 15周，以表征成熟对 ELAR响应。横断和剥脱研究将阐明迷走神经介导ELAR的传入支。的作用将通过以下方法评估介导ELAR的中央迷走神经核比较对远端食管伤害性刺激的反应，辣椒素在化学拮抗它们的P物质NK 1之前和之后受体。最后，远端给药后的心肺反应急性炎症食管的食管酸化将是与0.5%辣椒素刺激引起的ELAR比较。