MPO and Decreased total leukocyte count: The data described here are in accordance with previous work from Soares et al., who followed 5-FU-treated rats (1°, 3°, 5°, 15° and 30° day) and showed marked leukopenia, MPO activity, inflammatory cell infiltration, villus shortening, and crypt destruction in the duodenal lamina propria on the third day post-5-FU challenge [5].