Changes of tissue structure of gastric mucosa with aging in rats / 中华老年医学杂志

ABSTRACT

Objective To observe the changes of tissue structure of gastric mucosa with aging in rats. Methods Twelve healthy Wistar rats were divided into two groups: aged (12 months,n=6) and non-aged rats (3 months,n=6). The thickness of gastric gland and muscular layer of mucosa were observed under the light microscopy. Pepsin activity and the expression of proliferating cell nuclear antigen (PCNA) were detected by biochemical method and immunohistochemical method respectively. Results Intestinal metaplasia, dysplasia and adenoma were not found in gastric mucosa in two groups. In aged versus non-aged rat group, the thickness of gastric gland was decreased [(271.5±47.4) μm vs. (350.9±53.3) μm, t=2.731, P<0.05], while the thickness of muscular layer of mucosa was increased [(98.1±13.1) μm vs. (62.4±10.6)μm, t=5.174, P<0.01]. The content of pepsin in aged rats were lower than in non-aged rats[(3. 011±1. 222) U vs. (4.733±1.304) U, t= 2.361, P<0.05]. Immunohistochemistry results showed that the positive cells of PCNA were located in gastric stem cells in cervical part, and the thickness of the gastric stem cells was decreased in aged rats. Conclusions The incidences of gastric gland atrophy and muscular layer hypertrophy are increased, and the secretion of pepsinogen and the proliferation ability of gastric stem cells are decreased in aged rats.