Oleic acid as an inhibitor of gastric H+, K(+)-ATPase.
A study was made of the effects of oleic acid on gastric H+, K(+)-ATPase. Oleic acid inhibited both H+, K(+)-ATPase and K(+)-pNPPase from pig gastric mucosa. The concentrations for 50% inhibition were 7.8 x 10(-6) M and 5.0 x 10(-6) M respectively. Oleic acid also inhibited Na+, K(+)-ATPase with an IC50 value of 1.2 x 10(-5) M. Double reciprocal plots demonstrated the inhibition of gastric H+, K(+)-ATPase by oleic acid to be noncompetitive with respect to K+ and competitive with respect to ATP. A proton transport experiment also showed oleic acid to inhibit H+, K(+)-ATPase mediated acid secretion. Oleic acid may thus possibly be a potent inhibitor of gastric H+, K(+)-ATPase and that the inhibition of H+, K(+)-ATPase may be responsible for the antisecretory effect of oleic acid.
Murakami
S
S
Research Center, Taisho Pharmaceutical Co., Ltd., Saitama, Japan.
Muramatsu
M
M
Otomo
S
S
D009597:4-Nitrophenylphosphatase / Q000037:antagonists & inhibitors; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000818:Animals; D005753:Gastric Mucosa / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D017506:H(+)-K(+)-Exchanging ATPase; D066298:In Vitro Techniques; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology*; D013552:Swine
D009829:Oleic Acids; D019301:Oleic Acid; D009597:4-Nitrophenylphosphatase; D000251:Adenosine Triphosphatases; D017506:H(+)-K(+)-Exchanging ATPase