Effects of KCl and insulin on benzimidazole-inhibited canine gastric secretion.
The final step in acid secretion is believed to result from the H+-K+-ATPase-mediated exchange of H+ in the parietal cell, with K+ in the lumen. To study the K+ secretion we used Picoprazole and insulin separately and together to inhibit gastric secretion stimulated in gastric fistula dogs with histamine (100 micrograms X kg-1 X h-1). Picoprazole, a substituted benzimidazole (750 mg/kg), reduced gastric H+ concentration and volume with a rise in K+ concentration [( K+]) to 20-25 meq/l. Insulin alone inhibited acid output to the same extent as Picoprazole but with a marked fall in [K+]. Insulin (0.6 U/kg) given with Picoprazole did not alter inhibition of H+ but prevented the large decrease in gastric juice [K+]. An injection of KCl (1 meq/kg) 1 h after Picoprazole did not alter the effects of the inhibitor. Pepsin secretion after insulin was delayed by Picoprazole, whereas during bethanechol chloride infusion (80 micrograms X kg-1 X h-1) pepsin output was reduced for a shorter period and to a lesser extent than acid. We concluded that insulin affects gastric H+ and K+ secretion by a mechanism not related to H+-K+-ATPase and that Picoprazole affects pepsin secretion probably indirectly via its effect on the parietal cell, where its action is quite consistent with an effect limited to inhibition of the H+-K+-ATPase of the parietal cell.
D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D002712:Chlorides / Q000032:analysis; D004285:Dogs; D005750:Gastric Juice / Q000187:drug effects / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D010434:Pepsin A / Q000378:metabolism; D011188:Potassium / Q000032:analysis; D011189:Potassium Chloride / Q000494:pharmacology*; D012964:Sodium / Q000032:analysis
D001562:Benzimidazoles; D002712:Chlorides; D007328:Insulin; D011189:Potassium Chloride; D006632:Histamine; D012964:Sodium; C031000:benzimidazole; D010434:Pepsin A; D011188:Potassium