Age-Associated Changes In The Histology And Ultrastructure Of Pyloric Glands

Objective To investigate the aging changes in the histology and ultrastructure of pyloric glands.Methods Sixty subjects with relatively normal gastric tissues were enrolled,with 20 subjects in the younger group (20-59 years) and 40 subjects in the elderly group (≥60 years).The latter group included 15 subjects aged from 60 to 69 years,13 subjects aged from 70 to 79 years and 12 subjects aged from 80 to 89 years.Under light microscopy,the histology and morphology of pyloric glands were observed to determine the thickness of the lamina propria and the Ap:Al ratio (Ap:area of the parenchyma,Al:the area of gastric mucosa lamina proprias),and to compare the morphology of the lamina propria,pyloric gland and gland cells in each group.The ultrastructure of pyloric gland cells was examined under electron microscope.Results From 20-59 age group to 60-69 age group to the 70-79 age group,the thickness of the lamina propria showed a decreasing trend from [(649.8± 127.9) μm to (634.6±121.4) μm and to (615.7 ± 74.6) μm,respectively,F=0.270,P=0.765],but the thickness of the lamina propria in 80-89 age group was increased to (645.5± 99.9) μm,comparable to that in the 20-59 age group.From 20-59 to 60-69 to 70-79 to 80-89 age group,the Ap to Al ratio (％) showed a significant decreasing trend from [(37.6 ± 6.5) ％ to (34.7 ± 5.0) ％ to (31.5 ± 6.4) ％ to (28.3 ± 4.7) ％,F=5.010,P=0.005] ; the average Ap to Al ratio in the elderly group was significantly lower(31.6±5.9) ％ than in the younger group(37.6±6.5) ％ (t=3.181,P=0.003).Interstitial hyperplasia of the lamina propria,sparse arrangement of pyloric glands,pyloric glands cells nucleienlarged and deeply stained and fuzzy cell boundaries were more clearly seen in the elderly group (especially 80-89 age group) as compared with the younger group.There was no significant difference in the ultrastructure of pyloric gland cells among each group.The average Am:Ac ratio (Am:the area of mucous granule,Ac:the area of cytoplasm of pyloric gland cell) showed a decreasing trend with age (F=19.831,P=0.000).The average Am:Ac ratio in the elderly group [(25.68±4.62) ％] was significantly lower than that in the younger group [(34.66 ±4.34) ％] (t=-6.456,P =0.000).Conclusions Along with aging,the thickness of the lamina propria has a decreasing trend,the density of pyloric glands is gradually decreased,while the connective tissue between the glands is increased.The density of mucous granules in pyloric cells associated with mucus secretion is also decreased.Hence,in the elderly,gastric antral mucosa and its functional glands have deteriorated performance and morphology.