Waldron-Edward D, Skoryna S C
Can Med Assoc J. 1966 Jun 11;94(24):1249-56.
A method which will reduce significantly the viscosity of epithelial mucus is essential to the physiological mechanisms involved in the mobilization and removal of such secretions. The life expectancy of patients with chronic pulmonary conditions and cystic fibrosis has been considerably increased and consequently the problem of liquefying mucin acquires new importance. In view of these considerations, as well as to facilitate research into the structural relationship of the glycoprotein macromolecule, a systematic investigation of mucolysis was undertaken using gastric mucin. Three amides, carbamide, acetamide and formamide, were found to dissolve gastric gel mucin with minimal degradation, and rapidly disperse the viscous secretions produced in pathological conditions of the tracheobronchial tree. Their effect on secretions from patients with cystic fibrosis and bronchiectasis is dramatic, and within five minutes of adding the reagent the flow time was reduced by at least 95%. Clinical studies were carried out with carbamide (urea in anhydrous, lyophilized, sterile powder form) in 32 patients with a variety of bronchial conditions, including chronic bronchitis, cystic fibrosis, asthma, bronchiectasis and emphysema. With the concentrations used, no irritant, bronchospastic or other reactions were observed.IT IS CONCLUDED THAT AMIDES OF THIS TYPE HAVE AT LEAST TWO ACTIONS ON THE EPITHELIAL MUCOUS SECRETION: (1) breakage of the three-dimensional gel structure and (2) a slower reduction in viscosity followed by solution of the solid material.
一种能显著降低上皮黏液黏度的方法对于此类分泌物的移动和清除所涉及的生理机制至关重要。慢性肺部疾病和囊性纤维化患者的预期寿命已大幅提高，因此使黏蛋白液化的问题具有了新的重要性。鉴于这些考虑因素，以及为了便于研究糖蛋白大分子的结构关系，使用胃黏蛋白对黏液溶解进行了系统研究。发现三种酰胺，即尿素、乙酰胺和甲酰胺，能以最小程度的降解溶解胃凝胶黏蛋白，并迅速分散气管支气管树病理状况下产生的黏性分泌物。它们对囊性纤维化和支气管扩张患者分泌物的作用显著，加入试剂后五分钟内，流动时间至少减少了95%。对32名患有各种支气管疾病（包括慢性支气管炎、囊性纤维化、哮喘、支气管扩张和肺气肿）的患者使用尿素（无水、冻干、无菌粉末形式）进行了临床研究。在所使用的浓度下，未观察到刺激、支气管痉挛或其他反应。结论是，这类酰胺对上皮黏液分泌至少有两种作用：（1）三维凝胶结构的破坏；（2）黏度的缓慢降低，随后固体物质溶解。
