A double-blind placebo-controlled study of buspirone-stimulated prolactin release in non-ulcer dyspepsia - are central serotoninergic responses enhanced?

Background: Dyspepsia is a common symptom for which an organic cause is fou nd in only 40% of patients. When no cause is apparent and the dyspepsia is considered to be idiopathic, a diagnosis of non-ulcer dyspepsia is made. Th e pathophysiology of non-ulcer dyspepsia is poorly understood and numerous theories have been put forward, including a theory of enhanced central sero toninergic receptor sensitivity. Aim: To determine the sensitivity of serotonin receptors in non-ulcer dyspe psia. Methods: Using a randomized, double-blind, placebo-controlled design, we co mpared buspirone (a serotonin type 1a partial agonist)-stimulated prolactin release in 50 patients and 59 healthy comparison subjects. Buspirone, 30 m g, or matching placebo was adminisover 180 min was monitored. Patients and healthy subjects received both treatments in random order, 1 week apart. Results: Overall, patients with non-ulcer dyspepsia had greater prolactin r elease in response to the buspirone challenge than the healthy comparison s ubjects, with differences most significant at 90 min following the challeng e. Enhancement occurred in patients both with and without Helicobacter pylo ri infection. Female subjects, both patients and healthy volunteers, showed a greater response to buspirone than male subjects, and the augmentation o f response observed in male and female patients was greater in females. Conclusions: Patients with non-ulcer dyspepsia have enhanced central seroto ninergic responses and such responses are independent of H. pylori infectio n. Blockade of such receptors might be an appropriate therapeutic strategy.