H+/K+ ATPase expression in human parietal cells and gastric acid secretion in elderly individuals

Objective To investigate whether the ultrastructure and hydrogen potassium adenosine triphosphate (H+/K+ ATPase) expression of human parietal cells were associated with aging. Methods In all, 50 participants who underwent gastroscopy due to dyspepsia were divided into two age groups, with 19 in the younger group (YG, aged 20–59 years) and 31 in the elder group (EG, aged ≥60 years). The ultrastructure of their parietal cell was determined by electron microscopy (EM), and the expressions of H+/K+ ATPase α-subunit mRNA and β-unit protein were detected. Furthermore, 24-h esophageal pH monitoring was performed in the two groups. Results EM images showed no distinct difference in the morphology and distribution of parietal cells or the acid secretion-related organelle between the two groups. There were no differences between YG and EG in the proportion of mitochondria and the tubulovesicular system area. The expressions of H+/K+ ATPase α-subunit mRNA and β-subunit protein showed no age-related alteration between YG and EG. The expression of H+/K+ ATPase α-subunit mRNA in EG was higher than that in YG, whereas the expression of β-subunit protein was significantly higher in those aged ≥80 years than in the YG. No significant difference was found in the 24-h esophageal pH monitoring between YG and EG. Conclusion Acid secretion-related organelles in parietal cells do not degenerate with aging, the expression of H+/K+ ATPase even shows a trend to increase, indicating the existence of intact molecular biological basis for acid secretion in healthy elderly individuals.