The effect of beta-adrenergic and cholinergic blockade on the circadian rhythm of gastrins in serum.

The importance of beta-adrenergic and cholinergic mechanisms to the circadian rhythm of gastrins in serum was studied in 15 healthy volunteers. The subjects were investigated during peroral treatment with 1) a beta-adrenergic blocking drug (propranolol), 2) an anticholinergic drug (glycopyrron), 3) both drugs, and 4) without treatment. Gastrin concentrations were measured with an antiserum that measures all four main components of gastrin in serum, and with a gastrin-17 specific antiserum. A circadian rhythm was observed with both antisera. The total immunoreactivity in serum increased from 39 pg per ml +/- 3 (mean and S.E.M.) in the morning to a peak at 2300 (77 +/- 7), followed by a nadir at 0400 (38 +/- 2). The circadian rhythm was maintained during administration of the drugs, but the concentrations of component III (gastrin-17) were reduced by beta-adrenergic blockade, while the anticholinergic treatment increased the concentrations of the other gastrin components. The inhibition of gastric secretion of acid by anticholinergics is presumably due to an action on the parietal cells; according to this study, the inhibition is connected by an increased gastrin stimulus. Beta-adrenergic blockade, on the other hand, seems to reduce the gastrin stimulus and might be of therapeutical interest in duodenal ulcer disease.