Rats receiving 14 daily gavage doses of 100 or 200 mg/kg ethyl acrylate (EtAc) and killed at varying times following the end of dosing ehxibited dose-dependent lesions and recovery from lesions in the forestomach. The glandular stomach which was previously shown to be affected by acute exposure to EtAc appeared to have adapted to resist EtAc toxicity with repeat exposure and appeared normal in all animals. Adaptation of the forestomach was characterized by increased papillomatous thickening with dose. Lesions observed in acute exposure to EtAc were still present with repeat dosing and were more pronounced at the high dose. Forestomachs of rats which received 100 mg/kg EtAc for 14 days were recovered to normal within 2 weeks following the last dose. Forestomachs of rats receiving 200 mg/kg EtAc still exhibited numerous lesions 2 weeks following the last dose, and mucosal hyperplasia was present in these forestomachs at 4 weeks post-exposure. Two lesions, submucosal fibrosis and foreign body reaction, became more prevalent in high-dose animals with time. Foreign body reaction was present in all high-dose animals 4 weeks postexposure.
