Absorption and distribution of S35O2 inhaled through the nose and mouth by dogs1

Journal/Book: Reprinted from THE AMERICAN JOURNAL OF PHYSIOLOGY Vol. 197 No. 6 December 1959 Printed in U.S.A.. 1959;

Abstract: Vanderbilt University Medical School and Hospital Nashville Tennessee BALCHUM OSCAR J. JERZY DYBICKI AND GEORGE R.MENEELY. Absorption and distribution of 5350 z inhaled through the mouth and nose by dogs. Am. J. Physiol. 197(6): 1317-1321. 1959.-Dogs breathing S35O2 through the nose and mouth retained a smaller proportion of the inhaled gas in the trachea lungs hilar lymph nodes and liver and spleen than those breathing similar concentrations via a tracheostomy. This conclusion is substantiated by tissue S35 concentration assays and measurements of the compliance of the lungs and thorax and of pulmonary resistance. The upper airways therefore partially protect the lungs from exposure to sulfur dioxide. Received for publication June 1 1959. 1 This investigation was supported in part by PHS Contract SAph 70219 Air Pollution Medical Program Experimental. Some of the facilities were available through grants-in-aid of research from the National Institute of Arthritis and Metabolic Diseases Graduate Training Grant 2A5129 Army Medical Research and Development Command DA-49-007-MD-995 and the U.S. Steel Research Foundation Inc. 2 Present address: Dept. of Medicine University of Southern California School of Medicine 2025 Zonal Ave. Los Angeles 33 Calif. 3 Rockefeller Foundation Research Fellow Gdansk Poland. THE INHALATION of sulfur dioxide even in low concentrations results in a decrease in compliance and an increase in pulmonary resistance (1 2). It has striking irritative effects when introduced directly into the lungs (3) and acts as a stimulus to the nerve fibers in the bronchi (4). Amdur and Mead (I) have stated that the upper airways provide partial protection against sulfur dioxide since a given concentration reaching the lungs through a tracheal cannula produced effects far greater than estimated an the basis of the reaction observed when inhalation had been via the nose mouth and pharynx. We have previously described (2) the effects of S35O2 in various concentrations upon pulmonary function in the dog its distribution in the viscera and its concentration in the tissues when administered via a tracheostomy. The following study was designed : a) to evaluate the role of the upper airways as a protective mechanism and to detect whether they are effective in reducing the amount of SO2 gaining access to the lungs and being absorbed by them and b) to determine quantitatively the distribution of S35 to various organs and tissues of the dog under these conditions of exposure. ... ___MH

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