EFFECTS OF THE MERCURIAL DIURETIC MERSALYL ON PROTEIN-BOUND SULFHYDRYL GROUPS IN THE CYTOPLASM OF RAT KIDNEY CELLS

¹ Departments of Pharmacology and Anatomy, State Univetsity of New York, Upstate Medical Center, Syracuse, N. Y.

Diuretic doses of mersalyl reduced cytoplasmic protein-bound sulfhydryl concentrations in the cells of terminal portions of proximal tubules and their brush borders, loops of Henle, and medullary collecting ducts of rat kidney tissue. The loops of Henle seemed to be more sensitive to small doses of mersalyl than other portions of the tubules but straight portions of proximal tubules exhibited the most rapid response.

BAL reversed the effects of mersalyl when administered before or after the mercurial; cysteine was ineffective.

Protein concentrations, as determined by the Millon and Brom Phenol Blue methods, were not altered by mersalyl.

The data suggest that mercurials exert a diuretic effect by inhibiting sulfhydryl groups of the tissue proteins in various kidney cell types.

It is possible that distinct reabsorptive mechanisms are suppressed by mercurials and that such mechanisms may involve both volume and concentration regulation.