MINIMAL SODIUM LOSSES THROUGH THE SKIN 1

Abstract

The widespread admn. of very low Na diets makes it highly desirable to determine the amts. of Na lost from the human body by each of the 3 excretory paths. Urinary and fecal losses have been investigated thoroughly, but there is a paucity of reliable data regarding the loss of Na through the skin under conditions in which the sweat glands are inactive. Two normal young male subjects were placed on a daily dietary intake of 10 m. eq. of Na and, after achieving Na balance, were placed in a cool environment and on greatly restricted activity to avoid sweating. Urinary and fecal Na were detd. together with the losses of Na through the skin. The latter were 4.06 m.eq. and 4.40 m.eq./24 hrs.,respectively. Calculated on the basis of surface area, the values for the 2 subjects were 2.22 m.eq. and 2.18 m.eq./square meter of body surface/24 hrs. An incidental finding was a diuresis of water and Na during the 3 days of inactivity in a cool environment.