{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T03:46:59Z","timestamp":1777866419722,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2009,2,5]],"date-time":"2009-02-05T00:00:00Z","timestamp":1233792000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2009,2,5]],"date-time":"2009-02-05T00:00:00Z","timestamp":1233792000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Digestion"],"abstract":"<jats:p>The in vitro effect of ammonium bicarbonate buffer on mucus H+ permeability is reported here. The diffusional resistance of mucus and water was demonstrated to be dependent on buffer concentration, and the contrast between the two types of layers was most pronounced for low buffer concentration near neutrality. Moreover, the pK&lt;sub&gt;a&lt;\/sub&gt; values of HCO&lt;sub&gt;3&lt;\/sub&gt;- and NH&lt;sub&gt;3&lt;\/sub&gt; had a profound effect on measured D&lt;sub&gt;HCl&lt;\/sub&gt; These in vitro studies suggest that a potentially damaging high local concentration of NH&lt;sub&gt;3&lt;\/sub&gt; and HCO&lt;sub&gt;3&lt;\/sub&gt;- within the mucus layer generated by the action of Helicob\u03b1cter pylori urease on endogenous intragastric urea could greatly accelerate proton flux to the surface epithelium by operation of a buffer shuttle. This results in enhanced H+ permeability, particularly at pK&lt;sub&gt;a&lt;\/sub&gt; values of HCO-&lt;sub&gt;3&lt;\/sub&gt; and NH&lt;sub&gt;3&lt;\/sub&gt;, and that in extreme circumstances this may result in gastric ulcer formation.<\/jats:p>","DOI":"10.1159\/000201008","type":"journal-article","created":{"date-parts":[[2009,2,7]],"date-time":"2009-02-07T01:50:30Z","timestamp":1233971430000},"page":"32-39","source":"Crossref","is-referenced-by-count":8,"title":["Enhanced H\n                    <sup>+<\/sup>\n                    Diffusion by NH\n                    <sub>4<\/sub>\n                    <sup>+<\/sup>\n                    \/HCO\n                    <sub>3<\/sub>\n                    <sup>-<\/sup>\n                    : Implications for Helicobacter-pylori-Associated Peptic Ulceration"],"prefix":"10.1159","author":[{"given":"M.A.","family":"Desai","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P.M.","family":"Vadgama","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2009,2,5]]},"container-title":["Digestion"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/201008","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000201008","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T08:39:48Z","timestamp":1777538388000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000201008"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,2,5]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000201008","archive":["Portico"],"relation":{},"ISSN":["0012-2823","1421-9867"],"issn-type":[{"value":"0012-2823","type":"print"},{"value":"1421-9867","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,2,5]]}}}