THE MODE OF ACTION OF A MERCURIAL DIURETIC IN MAN

Abstract

Intraven. injn. of 0.2 g. mersalyl in normal human subjects caused the urinary concns. of Na and Cl to alter in such a way that the concn. of Na tended towards the plasma Na concn. and the concn., of Cl tended towards 1.5 times the plasma Cl concn., regardless of whether the prevailing urinary concns. were above or below the plasma concns. before mersalyl was given. This suggests that the urine formed at the peak of a mercurial diuresis is similar in electrolyte composition to the fluid in the proximal convoluted tubules of the kidney. Since mersalyl is incapable of producing more than a slight augmentation of a max. water diuresis, these effects on water and electrolyte excretion are believed to be located mainly in the distal convoluted tubule.