Inhibition of gastric H+ secretion, K+-ATPase and K+-phosphatase by estradiol in vivo and in vitro

Abstract

The effect of estrogen on the gastric acid secretion and H+-transporting enzymes, K+ -ATPase and K+-phosphatase, were investigated in the rat. The maximum H+ secretory rate in response to 1 mM histamine was significantly reduced (P < 0.05) in both the isolated gastric mucosa obtained from the rats treated with estradiol in vivo for 7 days and the mucosa directly incubated in vitro with estradiol. The inhibitory effect on the gastric enzyme activities in vitro showed a dose-dependent pattern of a noncompetitive type. The result suggested that estradiol may have a direct action on the gastric H+ secretion by inhibiting the H+ transport enzyme activities.