Free amino-acids in human sweat from different parts of the body.

Abstract

THE presence of free amino-acids in human sweat has been known since 1910 when Embden and Tachau1 isolated serine from this secretion. In 1946, Hier, Cornbleet and Bergeim2 identified arginine, histidine, isoleucine, leucine, lysine, phenylalanine, threonine, tryptophane, tyrosine and valine in human sweat; they were also able to demonstrate that the amount of amino-acids secreted in sweat is independent of the diet and of variations in amino-acid levels in the blood; Rothman and Sullivan3 found two additional amino-acids to be present in sweat, ornithine and citrulline. This observation, together with the high urea level of sweat4, led to the hypothesis that urea is formed in the sweat glands2,3. Hamilton5, and Oro and Skewes6, using ultra-micro methods, found the relative concentrations of amino-acids on the surface of the fingers of ten subjects to be essentially constant. Other authors7 who sampled sweat from the whole body surface, rather than from a single area, reported greater individual differences.