Excretion of Lactic Acid in Sweat

Abstract

The reaction, osmotic pressure and volume relationship of the body fluids are closely dependent on the properly regulated acid-base equilibrium. Under normal conditions 800.to 1000 cc. of fluid are lost through the skin in 24 hours; while under special conditions such as athletic contests, heavy work such as mining, etc., this may be increased to as much as over 3 liters per hour. Even under normal conditions there is a much greater amount of acid claiming excretion than fixed base taken in. During exertion this lack of balance between fixed base and acid catabolites is augmented and some regulatory mechanism is essential if the fixed base depots of the body are not to be abnormally drained. We have attempted to investigate how some of these regulatory devices operate to conserve base within the body during the excess sweating which takes place in patients whose temperature is raised to high levels for therapeutic reasons. These patients are taken at random and subjected to this therapy for causes as varying as acute gonorrheal infections, paralysis, psoriasis, etc., so that the results obtained are probably generally applicable and not due to the specific pathological condition.

The base economy factor of the skin will depend on its ability to produce a fluid of lower pH than the blood plasma which acts as the carrier of the catabolic products. The sweat as collected from the surface of the entire body at intervals after the temperature of the patients has been raised showed a pH of about 4-4.5. It is a known fact that athletes complain of “stinging sweat”. The production of an acid that could be eliminated un-ionized to a low degree at the pH of sweat would result in a great sparing of base.