Inhibition of MAPK phosphorylation impairs the proliferation in the gastric epithelium in early-weaned rats.

<p>(A and B) Hematoxylin & Eosin stained sections of the gastric mucosa of 18-day-old early-weaned rats. Arrows indicate mitotic cells. Original magnification: 40×. (D and E) Immunohistochemistry for PCNA developed with DAB and counterstained with Mayer's Hematoxylin. (F) Negative control. Original magnification: 20×. (C) Mitotic Index (MI) and (G) Proliferative Index (PI) in 18-day-old early weaned rats treated with 0.5% DMSO (control) or PD98059 at 300 µg/kg. Indices are represented by bars as means±SD. MIs and PIs were obtained after counting 2,500 epithelial cells/animal, and they represent the number of mitotic or PCNA-labeled cells/total number of epithelial cells. (n) number of animals in each group. Results were analyzed statistically by Student <i>t</i> test. *p<0.05 when compared to the control group.