RENAL DYSFUNCTIONS IN WHITE RATS AFTER A SINGLE ADMINISTRATION OF GENTAMICIN

THE AIM of the investigation was to study kidney functions in white rats, the mechanisms and dynamics of the development, determination of dosedependent toxic effects of gentamicin (G) after a single administration of the drug under conditions of induced water diuresis. MATERIAL AND METHODS. The influence of G on the kidney function was studied in 28 white male rats with body mass 160180 g under conditions of induced water diuresis in 2 hours after a single intraperitoneal injection of the drug in doses 10mg/100g body mass and 20 mg/100 g body mass. The amount of urine, content of protein in it, creatinine concentration and osmolality of urine and blood plasma were determined. RESULTS. It was found that injection of G to rats in dose of both 10 mg and 20 mg/100 g of body mass resulted in a reliable decrease of diuresis as early as within 2 hours both in the absolute and relative values, especially after injection of 20 mg. Excretion of protein was noted to increase proportionally to the dose of the drug injected, the indices of specific proteinuria by the acting nephrons being increased. The decreased glomerular filtration rate by clearance of endogenous creatinine, moderately increased content of blood plasma creatinine were noted. Clearance and fraction of osmotically free water in water diuresis, impairment of maximal osmotic dilution of urine were found to decrease suggesting impaired osmoregulating function of the kidneys. The dysfunction revealed can be considered as an evidence of nephrotoxicity of G at a single injection.The dysfunctions revealed might be a result of impaired renal processes glomerular filtration and tubular reabsorption. CONCLUSION. G injected in dose of 10 mg and 20 mg/100 g of body mass possesses a nephrotoxic action in rats within the first 2 hours after injection, that manifested itself as proteinuria, less diuresis and reduced glomerular filtration rate. Increased dose of G up to 20 mg/100 g of body mass resulted in increased proteinuria, that allows the nephrotoxic effect to be considered as dosedependent. Simultaneously a disturbance of the osmoregulating function of the kidneys is observed with their decreased ability to maximal dilution of urine.

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