Age-associated changes in ultrastructure and H+-K+-ATpase of gastric parietal cell in the elderly / 中华老年医学杂志

ABSTRACT

Objective To investigate the age-associated changes of ultrastructure,mRNA and protein expressions of H+-K+-ATPase in elderly gastric parietal cell. Methods Fifty patients with relative normal stomach without gastroduodenal diseases were enrolled,including younger group (aged 20-59 years,n=19) and elderly group (aged≥60 years,n=31).Furthermore,the elderly group was divided into 3 subgroups60-69 years old (n =11 ),70-79 years old (n=10 ),above 80 years old (n =10).The ultrastructure of gastric parietal cell was observed under electron microscope.The expression of H+-K+-ATPase α subunit mRNA and H+-K+-ATPase β subunit protein were assessed by quantitative real-time PCR and Western-blot,respectively.The ageing-associated changes of all these data were respectively compared. Results No significant difference was showed in the morphology of gastric parietal cell and acid-secretion-associated organelles among all the groups.The average ratio Am to Ac (Am means the area of mitochondria,Ac means the area of cytoplasm) of gastric parietal cell and the average At to Ac ratio (At means the area of secretory canaliculi and tubulovesicular system )between younger group and elderly group had no significant difference[(48.4±7.5) ％ vs.(50.6±7.6) ％,t=-0.775,P=0.444; (13.8±4.1) ％ vs.(12.2±4.7) ％,t=0.984,P=0.332].Meanwhile,there were no distinctions in the expression of H+-K+ -ATPase α subunit mRNA and H+-K+-ATPase protein among all elderly subgroups(F=1.522,2.32,P=0.24,0.114).However,the mRNA expression of H+-K+-ATPase a subunit was higher in the elderly group than in the younger group(t=-3.682,P=0.001).Furthermore,the expression of H+ -K+ -ATPase protein in the elderly group was increased as compared with younger group(t=-3.389,P=0.004). Conclusions Acidsecretion-associated organelles of human gastric parietal cell have no degeneration and the expression of H + -K+-ATPase is in trend of increase with aging,indicating that healthy elderly people have the basis of ultrastructure and molecular biology to maintain well function of acid secretion.