Bismuth salts are currently used as monotherapy or in combination with antibiotics for the treatment of Helicobacter pylori-associated peptic ulcer disease. Besides encouraging clinical results with colloidal bismuth subcitrate (CBS), there is an ongoing fear of organ toxicity with the use of bismuth salts. To study potential toxic effects of CBS under short-term exposure, we tested the influence of CBS on amylase secretion from isolated rat pancreatic acinar cells under basal conditions and following carbachol (CCh) and ceruletide (CRT) stimulation. Basal secretion was reduced by 8.9 +/- 9.6% (n = 10) (mean +/- SEM) (P < 0.05), 5.2 +/- 9.2% (P < 0.05), 9.4 +/- 6.4% (P < 0.01), and 6.2 +/- 12.2% (P < 0.05) with 0.001, 0.01, 0.1, and 1 micrograms/ml CBS, respectively. With 10 micrograms/ml and 100 micrograms/ml CBS, basal amylase secretion was increased in a dose-dependent manner, by 13.7 +/- 11.7% (P < 0.05) and 24.5 +/- 12.8% (P < 0.01). CCh (10(-5) M)- and CRT (3 x 10(-10) M)-stimulated secretory responses were not altered significantly by any of the CBS doses used. In concentrations above 1 microgram/ml, CBS increased pancreatic amylase secretion. Amylase secretion in response to secretagogues was not affected by CBS. These findings are unlikely to be associated with a toxic effect of CBS on exocrine pancreatic acinar cell function.