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.
方法:成年雄性白化大鼠80只,随机分为4个年龄组,每组20只大鼠(青春期前,青春期,成人,和老年)。使用苏木精和曙红对胃标本进行光学显微镜检查,PAS和Masson的三色污渍。进行了caspase-3和诱导型一氧化氮合酶(iNOS)的免疫组织化学染色。超氧化物歧化酶(SOD)的测定,采用ELISA法检测胃组织匀浆中谷胱甘肽过氧化物酶(GPx)和丙二醛(MDA)活性。通过实时聚合酶链反应(PCR)对血管内皮生长因子(VEGF)基因表达进行定量分析。
结果:老年大鼠胃粘膜光镜检查发现胃腺变形和糜烂。表面粘液细胞,粘液颈细胞,顶叶和主细胞表现出细胞质破坏,核变性,细胞凋亡和氧化损伤。平均胃粘膜厚度有显著下降,随着年龄的增长,胶原蛋白含量增加,粘液含量减少。这些形态学变化与SOD和GPx活性的显著降低和MDA活性的增加有关,VEGF基因表达降低。
结论:老年大鼠胃黏膜表现为组织学和免疫组织化学改变。这些变化与氧化应激有关,抗氧化能力下降,血管生成减少。