THE ACTION OF HISTAMINE ON THE RESPIRATORY TRACT IN NORMAL AND ASTHMATIC SUBJECTS 1

Abstract

The reaction of the tracheobronchial tree to histamine was investigated in 10 normal subjects, 10 patients with a history of severe allergic tendencies, and 9 patients with varying degrees of bronchitis, emphysema and asthma. A Standard Benedict Roth Metabolism Apparatus was used for the vital capacity measurements which were recorded on a revolving smoked drum. In the first 2 groups, no notable reduction in vital capacity was observed after the intramusc. injn. of a dose of 0.36 rag., or the intravenous admn. of a dose of 0.02-0.03 mg. of histamine base. In the 3d group, the sensitivity of the tracheobronchial tree to histamine in asthmatic subjects was confirmed in 8 of 9 patients. This sensitivity varied from patient to patient, and with the degree of asthma. During any one period of observation, quantitatively similar amounts of bronchoconstriction, as measured by a decrease in the vital capacity, could be produced by identical amounts of histamine injected at intervals by either the intramuscular or intravenous route. Bronchoconstriction may also be induced by administering histamine under the tongue, or by nebulization. No evidence was adduced to show that the systemic reactions to histamine in asthmatic subjects differed from the systemic reactions in normals.