Leucovorin rescue of enteric lesions induced by high-dose methotrexate: a time-related study in mice.

In this study, different groups of mice were treated with a single high-dose of methotrexate or with a leucovorin-methotrexate association, and the changes in structure and cell types of the small intestine were studied histologically. The results suggested that leucovorin rescue diminished the degree of mitotic abatement induced by methotrexate in the first days after treatment, with better preservation of enteric structures and the cell type ratio.