Effects of adenosine infusion on gastric emptying in healthy volunteers

Background: A low dose of systemic adenosine infusion has been shown to ind uce antinociception in clinical experimental studies as well as in patients . There is no clinical information about the effect of adenosine on the mot ility of the gastrointestinal tract. The aim of this study was therefore to evaluate the effect of exogenous adenosine administration on gastric empty ing in man. Method: Ten healthy male volunteers (22-45 yrs) were included in a placebo- controlled, double-blind, randomised, cross-over study where the experiment s were separated by at least one week. During one session the volunteers re ceived a continuous intravenous infusion of adenosine (50 mu g kg-l min-l) initiated 15 min prior to the test of gastric emptying Ca standard test mea l, followed by oral acetaminophen, 2 g) and lasting throughout the experime nt (2 h). During the other experimental session an infusion of saline was g iven. Acetaminophen absorption test was used as an indirect measure of the rate of gastric emptying. Venous acetaminophen concentration curves were pr oduced and the maximum acetaminophen concentration (C-max), the time to rea ch the maximum concentration (T-max), and the area under the serum acetamin ophen concentration time curve from 0 to 60 min (AUC60) were calculated. Results: There was no difference between placebo and adenosine in C-max (19 7 vs. 199 mu mol L-1, P=0.80), T-max (23 vs. 45 min, P=0.14), AUC60 (9633 v s. 9111 min mu mol L-1, P=0.28). Conclusion: The results demonstrate that adenosine in a clinically antinoci ceptive dose of 50 mu g kg-l min(-1) does not affect the rate of gastric em ptying in healthy volunteers.