Increased sensitivity of gastric acid secretion to gastrin in cirrhotic patients with portacaval shunt.

We studied acid secretory responses to exogenous pentagastrin and to exogenous and endogenous gastrin in 12 stable cirrhotic subjects with portacaval shunt, 12 unshunted cirrhotics, and 12 normal subjects. Basal and stimulated serum gastrin concentrations as well as basal and maximum acid outputs were similar in the three groups. At low doses of either exogenous pentagastrin or gastrin-17 (G17), cirrhotics with portacaval shunt secreted significantly greater amounts of gastric acid than unshunted subjects. After low doses of intragastric peptone, cirrhotics with portacaval shunt secreted significantly more acid than unshunted cirrhotics and normal subjects. At each measured serum gastrin concentration after either exogenous G17 or intragastric peptone meals, cirrhotics with portacaval shunt secreted more acid than the unshunted control groups and their dose-response curve was significantly shifted to the left. Thus, in cirrhotic patients with portacaval shunt, gastric acid secretion is abnormally sensitive to both exogenously administered or endogenously released gastrin.