TERATOGENICITY OF METHANOL FOLLOWING A SINGLE ORAL DOSE IN LONG-EVANSRATS

The teratogenicity of methanol was investigated following a single ora l exposure preceded by an equal volume of mineral oil to guard against local gastric irritation, Four groups of pregnant Long-Evans rats wer e gavaged on day 10 of gestation with the following solutions: 0.0 (n = 13), 1.3 (n = 12), 2.6 (n = 11), and 5.2 (n = 10) mL MeOH/kg. Wilson sectioning (head only), gross necropsy, and Alizarin red skeletal exa minations were performed on day 20 of gestation, At 5.2 mL/kg, the dam s demonstrated >20% decrease in weight gain in comparison to the contr ol, which was the only clinical toxic manifestation or histopathologic change noted for the dams, Methanol at all doses failed to produce an y significant change in standard reproductive indices (e.g., postimpla ntation loss), A significant decrease in fetal body weight (11 to 19.5 %), however, was associated with prenatal oral ingestion of methanol, Both internal and external examination of the fetuses demonstrated a d ose-dependent increase in anomalies [0 = 0.6%, 1.3 mL/kg 3.7%, 2.6 mL/ kg 7%, 5.2 mL/kg 16.5% (litter percents)], The dose-related anomalies were undescended testes, exophthalmia, and anophthalmia. Thus, acute m ethanol given orally produces anomalies, even when there is no apparen t maternal toxic response, (C) 1997 Elsevier Science Inc.