呼吸器の感染防御機構に関する研究 : 第 3 篇呼吸器感染防御因子としての気管支洗浄液中液性成分に関する研究

Abstract

Amounts of immunoglobulins, lysozyme and antitrypsin in bronchial lavage fluid were measured by using rats (Wistar strain, female) in order to examine an effect of cigarette-smoking. Each group of rat was inhalated a certain amount of cigarette-smoke by a smoking apparatus (Hamburg type II) for 10, 20, 30 and 40 min, respectively. In another experiment, a group of rat was exposed to the smoke for 15 min daily for two weeks. After the inhalation, the bronchus was lavaged with 2 ml of sterile saline and the supernatant was collected individually. IgA and IgG were measured by immunodiffusion technique. Lysozyme was determined by a biological method. Antitrypsin activity was measured by James' method. The results were summarized as follows : 1) Lysozyme level increased 10 min after the start of the inhalation and reached to the peak at 20 min. The level decreased into normal range within 40 min. 2) A pattern of IgA was similar to that of lysozyme. The maximum peak of IgA level was found at 20 min and decreased later. 3) IgG showed a different pattern from IgA and lysozyme. The level remained in the normal range for 30 min after the start of the inhalation and remarkably increased at 40 min. 4) A pattern of antitrypsin activity increased at 20 min after the start and decreased into normal range later. 5) A group exposed to cigarette smoke for 15 min daily for 2 weeks showed lower levels of lysozyme, IgA and antitrypsin than those of the groups exposed to single dose of smoke for 20 min. On the other hand, IgG levels were nearly the same for both groups. It was suggested that the secretion of lysozyme, IgA and antitrypsin in tracheo-bronchial tree were stimulated by the inhalation of cigarette smoking. However, the hypersecretion was seen in a short time and, after that, the secretion returned to the normal level, as if those special supplies were limited in the tracheo-bronchial tree.