Effect of short-term omeprazole administration on serum pepsinogens in relation to fasting serum gastrin and gastric acid secretion.

A study has been done in 10 male healthy volunteers of the effect of oral omeprazole 20 mg daily for 3 days on the serum concentrations of Pepsinogens A and C in relation to changes in fasting serum gastrin and basal and pentagastrin stimulated gastric acid output. The concentrations of Pepsinogens A and C showed concomitant and variable but significant increases, and the Pepsinogen A, C ratio did not change during the 3-day course of omeprazole. The increments were also significantly correlated with the increase in fasting serum gastrin and with the reduction in pentagastrin stimulated acid output. The correlations were mainly due to the marked inhibition of gastric acid secretion and the corresponding increases in serum gastrin and Pepsinogens A and C in two subjects, as in the other 8 subjects the changes were only modest. There appears to be a relationship, therefore, between the degree of inhibition of acid by omeprazole and the parallel increases in both serum pepsinogens and fasting gastrin.