The Diffusion of 35SO2 from Tissue Fluids Into the Lungs Following Exposure of Dogs to 35SO2

Abstract

Surgically isolated airways of head and neck in anesthetized, paralyzed dogs were exposed to 22 [plus or minus]2 ppm of 35SO2, delivered at 3.5 1 /min. for 30-60 min. Lungs were ventilated with ambient air by a positive displacement respiratory pump. In 10 of 12 measurements, over 95% of 35 SO2 administered was absorbed by the mucosa. In all animals 35 SO2 was present 1 or more expired gas samples collected either at the carlna or from a bronchus; this expired 35 SO2 could not have entered the lower airways in inspired air and its presence provided evidence that the lungs were releasing the gas in expiration, presumably from pulmonary capillaries. 35S was present in the blood and urine within minutes of the onset of exposure to 35SO2.