Ten and ninety-day toxicity studies of 2,4-dimethylphenol in Sprague-Dawley rats.

Abstract

Male and female Sprague-Dawley rats received 2,4-dimethylphenol daily by gavage for 10 or 90 consecutive days. The 10-day acute study doses were 0, 60, 120, 600 and 1200 mg/kg; the 90-day subchronic study doses were 0, 60, 180 and 540 mg/kg. Corn oil was used as the vehicle. In the 10-day study, all the high dose animals died. At 600 mg/kg there was a significant increase in relative liver weight in females and several significant alterations in hematologic and clinical chemistry values in both sexes. Histopathological examination revealed changes associated with the forestomach in all dose groups. The 90-day study had numerous compound-related deaths at the 540 mg/kg level. In addition, the final body weight in high dose males and females was significantly less while absolute lung weights and relative liver weights in females, and relative brain, kidney and testes weights in males were also altered. Significant clinical chemistry findings in high dose animals (540 mg/kg) included reduced creatinine and increased cholesterol in both sexes, with increased triglycerides and decreased AST in males only. Histopathologic evaluation revealed hyperkeratosis and epithelial hyperplasia of the forestomach in males and females in the middle and high-dose groups.