Persson C G
Dept of Clinical Pharmacology, University Hospital of Lund, Sweden.
Eur Respir J Suppl. 1990 Dec;12:652s-656s; discussion 656s-657s.
Plasma exudation into airway tissue and lumen is a defence and inflammatory reaction. If exaggerated it may become pathogenic as in asthma and rhinitis. Exuded plasma contains an abundance of mediators (kinins, complement fragments, fibrinolysis- and coagulation-peptides etc.) which have direct inflammatory and obstructive actions and which can attract, prime, and activate inflammatory cells. The plasma exudate may cause airway hyperresponsiveness by increasing mucosal thickness. In the lumen the exuded plasma is added to irritant and viscous secretions and plugs. Antiasthma and antirhinitic drugs, including glucocorticoids, disodium cromoglycate, beta-adrenoceptor agonists and xanthines, have anti-exudative actions that may include a direct reduction of vascular permeability and other anti-inflammatory effects. Recent data with nasal and tracheobronchial airways in guinea-pigs and humans suggest that plasma can pass into the airway lumen without disturbing the integrity of the epithelial lining as a barrier to inhaled molecules. Potent proteins from circulating plasma can, thus, promptly appear on the surface of a normal mucosa to neutralize offending materials. It is proposed that plasma exudation must be considered a first line mucosal defence system along with mucociliary transport in the airways.
血浆渗出到气道组织和管腔是一种防御和炎症反应。如果这种反应过度，就可能像在哮喘和鼻炎中那样致病。渗出的血浆含有大量介质（激肽、补体片段、纤维蛋白溶解和凝血肽等），这些介质具有直接的炎症和阻塞作用，并且能够吸引、启动和激活炎症细胞。血浆渗出物可能通过增加黏膜厚度导致气道高反应性。在管腔中，渗出的血浆会混入刺激性和黏性分泌物及堵塞物中。包括糖皮质激素、色甘酸钠、β肾上腺素能受体激动剂和黄嘌呤在内的抗哮喘和抗鼻炎药物具有抗渗出作用，可能包括直接降低血管通透性和其他抗炎作用。最近在豚鼠和人类的鼻及气管支气管气道上获得的数据表明，血浆可以进入气道管腔，而不会破坏作为吸入分子屏障的上皮衬里的完整性。因此，循环血浆中的强效蛋白质能够迅速出现在正常黏膜表面以中和有害物质。有人提出，血浆渗出必须被视为与气道中的黏液纤毛运输一样的一线黏膜防御系统。
