Distribution of35S in the Blood and its Excretion in Urine of Dogs Exposed to35SO2

Abstract
Blood 35S levels in anesthetized dogs rose progressively when the isolated upper airways were exposed to 35SO2 for 30 to 60 minutes, and decreased slightly in the hours following exposure. The plasma contained more 35S than the red blood cells (RBC); more than half of the plasma-35S was dialyzable, the greatest radioactivity among the nondialyzable fraction of the plasma being associated with α-globulin proteins. Two thirds of the RBC-35S appeared to be intracellular. RBC-35S/Plasma-35S was higher following in vivo exposure of animals than when plasma- 35S was mixed with nonradioactive RBC. Most of the urinary 35S was in the form of inorganic sulfate.