A spasm-inciting substance in the sputum during asthmatic attacks.

Abstract

Studies were carried out on eight cases of bronchial asthma whose ages varied between 25 and 56. Six of these cases had been found to be sensitive to one or more foreign proteins. Special care was taken to collect the sputa of every patient at the height of the attack, for it was thought that that would be the most favorable time to obtain the spasm-producing substance, if any such was present. The sputa thus obtained were extracted in alcohol, with the exception of two instances in which studies were made in the fresh state after being dissolved in Tyrode solution. The precipitate obtained with alcohol was also dissolved in Tyrode solution before using. The material obtained in this manner was tested on isolated strips of smooth muscle from cat's intestine, suspended in Tyrode solution. Prior to the actual experiment the constant contractility of the muscle to pilocarpine was first established.

As a result of these investigations it was found that the sputum of the asthmatics studied contained a substance which stimulated smooth muscle to contract. In most of our cases the contraction was prompt, spasmodic and sustained in character. In others it was slower but equally sustained for periods of five to seven minutes. In four cases where the sputum was studied in the interval of attacks, i. e., before and after the attacks, no contraction of smooth muscle was obtained—the kymographic registration showing a flat curve.

Control sputa prepared in a similar manner to the above from five cases of pulmonary tuberculosis, three of bronchiectasis, and five normal individuals gave absolutely negative results.

Further investigations are in progress to ascertain the nature of the substance and its significance.