Department of Pathophysiology, Comenius University, Jessenius Faculty of Medicine, Martin, Slovakia.
J Physiol Pharmacol. 2009 Nov;60 Suppl 5:93-7.
Cough and sneezing are upregulated during the upper airway diseases, most likely to enhance airway defense. The aim of this study was to assess the expiration reflex (ER), another expulsive defensive airway reflex, during allergic rhinitis (AR) and intranasal (i.n.) capsaicin challenge. Thirty male guinea pigs, sensitized to ovalbumin were used in the study. They were divided into 3 groups of 10 animals each: AR group (i.n. ovalbumin), capsaicin group (i.n. capsaicin 50 microM, 15 microl), and controls without any challenge. The animals were anesthetized with urethane (1.1 mg/kg) and allowed to breath spontaneously via tracheostomy. Metal canula was introduced into the right hemithorax to assess intrapleural pressure. ER was elicited by mechanical stimulation of the vocal folds using a thin nylon loop introduced upwards via tracheostomy. Maximal expiratory effort of ER (MEE) and the count of post-ER laryngeal coughs were evaluated. Mechanical stimulation of the vocal folds in controls produced isolated ER. They were followed by post-ER cough only in 11% of provocations. AR and capsaicin challenge increased MEE compared with that in controls (P<0.05). In these two groups of animals, the ER was followed by post ER-cough in 75% of provocations. The count of post-ER coughs in the group order control/AR/capsaicin was 0-2/2-4/1-3, respectively; P<0.05). The ER from the vocal folds is upregulated in a similar manner as is cough and sneeze. The central neuronal mechanisms are proposed to mediate this effect, but the spread of inflammation from upper airways to the larynx, verified histologically in the present study, may contribute as well.
咳嗽和打喷嚏在上呼吸道疾病中被上调，很可能增强气道防御。本研究旨在评估过敏鼻炎（AR）和鼻内（i.n.）辣椒素挑战期间的呼气反射（ER），这是另一种驱逐性防御气道反射。30 只雄性豚鼠被用于该研究，它们对卵白蛋白敏感。它们被分为 3 组，每组 10 只动物：AR 组（i.n. 卵白蛋白）、辣椒素组（i.n. 辣椒素 50 microM，15 微升）和无任何挑战的对照组。动物用氨基甲酸乙酯（1.1mg/kg）麻醉，并通过气管切开术允许自主呼吸。金属套管被引入右半胸以评估胸膜内压。通过经气管切开术向上引入的细尼龙环机械刺激声带来引出 ER。评估 ER 的最大呼气努力（MEE）和 ER 后喉咳嗽次数。在对照组中，机械刺激声带产生孤立的 ER。在 11%的激发中，它们仅在 ER 后引起咳嗽。与对照组相比，AR 和辣椒素挑战增加了 MEE（P<0.05）。在这两组动物中，ER 后有 75%的激发引发 ER 后咳嗽。ER 后咳嗽次数的组序为对照组/AR/辣椒素分别为 0-2/2-4/1-3，P<0.05）。声带的 ER 以与咳嗽和打喷嚏相似的方式被上调。提出了中枢神经元机制来介导这种效应，但本研究中组织学验证的从上呼吸道到喉部的炎症扩散也可能有贡献。
