Central serotonin receptors and delayed gastric emptying in non-ulcer 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 (t 1/2 = 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 1A receptors may have a role in the pathophysiology of non-ulcer dyspepsia of the dysmotility subtype.