Apical membrane of parietal cells contains which ion channels-
Ans. is 'b' i.e., H+ K+ ATPase o The H~ are produced inside the parietal cell through the reaction of metabolic CO., with water. The reaction is catalyzed by carbonic anhydrase. H+ is secreted by proton pump (H~ K'ATPase) into the gastric lumen in exchange with a K+ ion and the HCG, is transported out of the parietal cells at the basolateral membrane (by HCO3 - Cl- antiport ) into the interstitial fluid and from there into the blood. This HCO3- increases the blood pH. Hence after a meal, there is a rise in blood pH which is called the post-prandial alkaline tide.o The Cl" that enter the parietal cell in exchange for HCO3 are secreted into the lumen. So, inside the gastric lumen secreted H+ and Cl- from hydrochloric acid (HC1).
Na+ K+ ATPase
H+ K+ ATPase
Na+ K+ 2Cl- transporter
Na+ - Ca+2 cotransporter
G.I.T.