EFFECT OF DIFFERENT RENAL GLUTATHIONE LEVELS ON RENAL MERCURY DISPOSITION AND EXCRETION IN THE RAT

Mercury renal disposition has been studied following HgCl2 injection ( 5.0 mg/kg body wt., s.c.) in controls, diethylmaleate and N-acetylcyst eine-treated rats. The different treatments were used to generate stat istically different degrees of non-protein sulfhydryls concentration i n kidneys. Diethylmaleate (4 mmol/kg body wt., i.p.) diminished kidney glutathione levels to 25% and N-acetylcysteine (2 mmol/kg body wt., i .p.) increased kidney non-protein sulfhydryls levels up to 75% compare d with new controls. The amount of mercury in the kidneys, the mercury excretion rate in urine and the mercury plasma disappearance curves w ere calculated during 3 h post HgCl2 injection. BUN was measured in pl asma at the same time period to determine the onset of kidney damage. The results indicate a higher HgCl2 renal clearance in N-acetylcystein e-treated rats compared to controls and less renal mercury accumulatio n. The data agree with diminished renal toxicity. On the other hand, r enal mercury accumulation was higher and mercury renal clearance lower in diethylmaleate-treated animals, associated with higher renal toxic ity. The results suggest that non-protein sulfhydryl levels (principal ly glutathione) might determine renal accumulation of mercury as well as its elimination rate and hence might enhance or mitigate the nephro toxicity induced by the metal.