The effect of concomitant mercuric chloride and gentamicin on kidney function and structure in the rat

In order to define the possible effects of gentamicin on the course of experimental acute renal failure, the interaction between gentamicin and mercuric chloride was studied in rats. Acute renal failure was induced with 1 mg. of HgCl2 per kilogram intravenously. When given alone, HgCl2 produced a uniform, reproducible, nonoliguric, acute renal failure with a low mortality rate. Animals receiving gentamicin over the course of HgCl2-induced acute renal failure, in doses sufficient to produce a 1 hour postinjection serum concentration of 10 mug/ml., recovered glomerular filtration in a fashion similar to animals receiving only HgCl2(p greater than 0.05). Animals that recovered from HgCl2-induced acute renal failure were given 10 mg./Kg. of gentamicin every 4 hours for 15 days and developed proteinuria and decline in urine osmolality to the same degree as animals given gentamicin alone, but failed to develop azotemia. Nevertheless, morphological changes associated with gentamicin nephrotoxicity were found which were similar in severity to those seen with gentamicin alone. Animals pretreated with 10 mg./Kg. of gentamicin every 4 hours for 7 days were then given HgCl2. Acute renal failure in these animals was more severe than in animals receiving HgCl2 alone, as manifest by a greater degree of azotemia and death (p less than 0.05). The data indicate that in the rat the concomitant administration of gentamicin did not interfere with recovery from HgCl2-induced renal failure. Rats recovering from HgCl2-induced acute renal failure were resistant to a depression in glomerular filtration when given gentamicin. The prior administration of gentamicin enhanced the nephrotoxicity of HgCl2.