Experimental asthma induced by exposure to NO_2 : Effects on the delayed reaction

Abstract

We performed this study to determine the effect of the late asthmatic response, using guinea pigs exposed to NO_2 gas (0.5ppm) 6 times per week for 13 consecutive days. After completing of the fourth inhalation experiment, when sensitization via the respiratory tract by albumin of different species was established, the presence of the delayed dyspneic reaction was examined for 11 hours by the body plethysmographic method. By numerical study of various indices on the breathing curve, changes in fine respiratory symptoms were detected. Delayed tachypnea, extension of exhalation and decreased respiratory amplitude were noted as the result of NO_2 loading. An increase in the degree of dyspnea was also recognized in the evaluation by the values on the breathing curve pattern.