Seriate histomorphometry of whole rat stomach: an accurate and reliable method for quantitative analysis of mucosal damage.

The evaluation of mucosal damage in experimental models of gastric injury is commonly based on macroscopic detection of gross lesions and/or histological examination of tissue samples and is limited by the subjectivity of the examiner and by the paucity of nonrepresentative samples. This study proposes a novel method for the histomorphometric analysis of gastric damage, based on the examination of seriate parallel strips taken from whole rat stomachs. Strips were cut perpendicular to the lesser curvature, placed on a glass slide, with the side of each strip distal to the pylorus upward, and processed for routine histology. Sections were then observed by light microscopy: the length of damaged mucosa divided by the total length of mucosa, measured on a micrometric scale and expressed in percentage values, was indicated as the lesion index. Furthermore, to evaluate the severity of the damage, three types of lesions were discriminated depending on their depth: type I, lysis of luminal cells; type II, damage involving the cells lying on both surface mucosa and gastric pits; and type III, damage involving the lower part of the lamina propria with injury of glands associated with detachment of whole mucosal layers. Three models of acute gastric damage (ethanol, hemorrhagic shock, and indomethacin) were examined and treatment was also carried out with the antiulcer drugs omeprazole, ranitidine, and misoprostol, to show the advantages of this histomorphometric approach. The results indicate that this method allows an accurate quantitative analysis of gastric damage, and the effects of different antiulcer drugs can be better discriminated. Copyright 2001 Academic Press.