The Histopathological and Biochemical Response of the Stomach of Male F344/N Rats Following Two Weeks of Oral Dosing with Ethyl Acrylate*

Male F344/N rats were dosed with ethyl acrylate (EA) either by daily gavage or in the drinking water for 2 weeks. The gavage dose levels were 0, 2, 10, 20, 50, 100, and 200 mg/kg; the drinking water dose concentrations were 0, 200, 1,000, 2,000, and 4,000 ppm (corresponding to 0, 23, 99, 197, and 369 mg/kg/day, respectively). In those animals dosed by gavage, irritation of the forestomach increased in incidence and severity over the 20-200 mg/kg dose range. In those animals dosed with EA in the drinking water, a much lower incidence of forestomach irritation and less severe lesions were observed at corresponding dose levels. No lesions were observed in the glandular stomach from cither of the 2 modes of oral administration. Following 2 weeks of gavage dosing with EA, the total non-protein sulfhydryl (NPSH) content of the forestomach and glandular stomach, and the NPSH concentration of the liver were determined 2-24 hr after the last gavage dose. Animals dosed at 200 mg/kg reached approximately 11% of the ...