Age changes in the gastric mucosa of male albino rat: histological, immunohistochemical, histomorphometric and biochemical study.

Background: Age related changes in the stomach are associated with alterations in the structure and secretory function of the gastric glands. The present study aimed to investigate histological, histomorphometric and biochemical changes in the gastric mucosa of rats with age.

Materials and methods: Eighty adult male albino rats were randomly divided into four age groups, 20 rats in each (prepubertal, adolescent, adult, and senile). The gastric specimens were subjected to light microscopic examination using haematoxylin and eosin, PAS and Masson's trichrome stains. Immunohistochemical staining for caspase-3 and inducible nitric oxide synthase (iNOS) was carried out. Measurement of superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) activity in gastric tissue homogenates was performed using ELISA. Quantitative analysis of vascular endothelial growth factor (VEGF) gene expression was done by real-time polymerase chain reaction (PCR).

Results: Light microscopic examination of gastric mucosa of senile rats revealed distortion of gastric glands and erosions. Surface mucous cells, mucous neck cells, parietal and chief cells exhibited cytoplasmic destruction, nuclear degeneration, apoptosis and oxidative damage. There was a significant decrease in the mean gastric mucosal thickness, increase in collagen content and decrease in mucous content with the advance of age. These morphological changes were associated with a significant decrease in SOD and GPx activity and increase in MDA activity, in addition to decreased VEGF gene expression.

Conclusions: Gastric mucosa of aged rats showed histological and immunohistochemical alterations. These changes were associated with oxidative stress, decreased antioxidant capacity and decreased angiogenesis.