Mechanism of gastric antisecretory effect of SCH 28080

Br J Pharmacol. 1986 May;88(1):19-23. doi: 10.1111/j.1476-5381.1986.tb09466.x.


The mechanism of the gastric antisecretory action of SCH 28080 has been studied utilizing two different in vitro test systems, isolated and enriched parietal cells from the guinea-pig and guinea-pig gastric membranes purified and enriched with K+/H+-ATPase. In guinea-pig isolated and enriched parietal cells SCH 28080 inhibited the acid response to histamine and high K+ concentrations with IC50 values not significantly different from each other. SCH 28080 inhibited the purified K+/H+-ATPase measured in the presence of 5 mM KCl with an IC50 value of 1.3 microM. Kinetic studies indicated a competitive inhibition of ATPase by SCH 28080 with respect to K+. Studies on Na+/K+-ATPase showed that this enzyme was only slightly depressed by SCH 28080. It is concluded that SCH 28080 acts with high selectivity on the parietal cell K%/H+-ATPase, establishing its antisecretory effect by a competitive interaction with the high affinity K+-site of the gastric ATPase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Nitrophenylphosphatase / antagonists & inhibitors
  • Adenosine Triphosphatases / antagonists & inhibitors
  • Adenosine Triphosphatases / isolation & purification
  • Animals
  • Anti-Ulcer Agents / pharmacology*
  • Dogs
  • Gastric Juice / metabolism*
  • Gastric Mucosa / cytology
  • Gastric Mucosa / metabolism
  • Guinea Pigs
  • Imidazoles / pharmacology*
  • Kidney / enzymology
  • Kinetics
  • Phosphorylation
  • Proteins / metabolism


  • Anti-Ulcer Agents
  • Imidazoles
  • Proteins
  • Sch 28080
  • 4-Nitrophenylphosphatase
  • Adenosine Triphosphatases
  • calcium potassium ATPase