Renal and hepatic lesions induced by 2,2,4-trimethylpentane

The renal changes produced by 2,2,4-trimethylpentane, a constituent of unleaded gasoline, are studied in Wistar rats. The compound was given at a dose of 2 ml/kg daily by gavage dissolved in corn oil (2:1) to nine Wistar Albino rats. Nine control male rats received an equivalent dose of corn oil. Six animals were housed in metabowls to allow the collection of urine for enzyme and urinanalysis. The remaining three animals of each group were housed in a normal animal cage. After 2 days of treatment, all the test rats were noted to have lost weight and were killed on this or on the subsequent day. Macroscopic examination of the livers and kidneys revealed no visible lesions on the kidney, but two of the rats had white, slightly raised patches on the liver. Microscopic examination demonstrated centrilobular and confluent necrosis, hydropic degeneration and vacuolation of hepatocytes. Microscopic examination of the kidneys indicated eosinophilic hyaline droplet accumulation in the cells of the tubules, and tubular dilation. Analysis of plasma alkaline phosphatase and aspartate transaminase activity revealed increases consistent with liver damage. Analysis of urinary N-acetyl-beta-glucosaminidase and alkaline phosphatase activity showed increases consistent with renal toxicity. An apparent increase in the amount of cellular debris in the urine was also found, when the sediment was examined microscopically. From this study, it would appear that 2,2,4-trimethylpentane possess hepatotoxic as well as nephrotoxic properties.