CENTRAL SEROTONIN RECEPTORS AND DELAYED GASTRIC-EMPTYING IN NONULCER DYSPEPSIA

Objective-To determine whether central serotonin receptors are involved in the pathophysiology of non-ulcer dyspepsia. Design-Between subjects study of solid phase gastric emptying and prolactin response to buspirone challenge. Subjects-12 patients fulfilling criteria for non-ulcer dyspepsia and 12 age and sex matched controls. Main outcome measures-Solid phase gastric emptying measured by scintigraphic assessment of the movement of a standard meal labelled with technetium-99m and indium-111; responsiveness of central serotonin 1A receptors measured by the prolactin release following challenge with oral buspirone 60 mg. Results-Solid phase gastric emptying was significantly delayed in the patients with non-ulcer dyspepsia (t1/2=90.6 (SD 14.5) minutes in patients and 54.6 (10.7) minutes in controls; 95% confidence interval 24.7 to 46.7 minutes, p<0.001). Prolactin release was significantly greater in patients compared with controls (1272.7 (1039.9) mU/l v 292.9 (136.1) mU/l; 352.1 to 1607.5 mU/l, p<0.01). Gastric emptying and prolactin release were significantly correlated (r=0.59, p=0.04) in the patients but not in the controls (r=0.23). Conclusion-Central serotonin IA receptors may have a role in the pathophysiology of non-ulcer dyspepsia of the dysmotility subtype.