Abstract
Background: The acid/base transporters of human parietal cells have not been characterized yet. However, these transporters may play a role in the mechanism of acid secretion. The aim of this study was to investigate the transporters of the parietal cells obtained from human biopsy samples and dissects the mechanisms relevant to human pathology. Methods: Gastric glands were isolated from human biopsy samples by enzymatic digestion and then cultured for 48h. Parietal cells were identified using FITC-conjugated Dolichos biflorus lectin. The intracellular pH (pHi) of parietal cells was measured by using the fluorescence dye BCECF-AM. Results: Removal of Na+ from the standard HEPES solution perfusing the parietal cells caused a rapid and marked intracellular acidosis. Re-introduction of Na+ to the solution caused a complete pHi recovery. Since the solution did not contain HCO3-, this finding confirms the presence of a Na+ dependent H+ efflux mechanism in parietal cells. The Na+/H+ exchangers could be partially blocked by amiloride. The administration of standard HCO3-/CO2 rapidly and greatly decreased pHi. pHi recovery was not detected after the acidification suggesting the marginal role of HCO3- efflux into the parietal cells. In the absence of HCO3-, Cl- removal caused a small reversible alkalinization in parietal cells suggesting the small availability of HCO3- ions in the cytoplasm. However, in HCO3- containing solution a significantly higher alkalinization was observed. These results confirm functionally active Cl-/HCO3- exchange mechanisms in parietal cells. We found that histamin could stimulate proton secretion which could be blocked by ranitidine and pantoprazole. Conclusions: The fluorescence measurements revealed that human parietal cells express functionally active Na+/H+ and Cl-/HCO3- exchangers and proton pumps. However, we could not identify functionally active Na+/HCO3- co-transporters. This method is also suitable to study the regulation of the proton pump. This work was supported by OTKA, MTA and OM
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
