[Excretion and metabolism of dopamine in patients with functional dyspepsia]

Dopamine is one of major neurotransmitter in the central and peripheral nervous system. A significant amount of dopamine is also produced in the visceral nervous system and in gastrointestinal tract, where exhibits inhibitory activity on motility.

The aim of the study was to assess the parameters of dopamine secretion and metabolism in patients with functional dyspepsia.

The study was conducted in a group of 30 healthy subjects and 60 patients with functional dyspepsia (FD), that met the Rome Criteria III, for epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS). The severity of dyspeptic symptoms was determined using a 10-point Visual-Analogue Scale (VAS). Fasting plasma concentration of dopamine (DA) and the contents of homovanillic acid (HVA) in the urine collection were determined by ELISA.

DA concentration in plasma was similar in both clinical forms FD (EPS - 55.6 pg/ml, in patients with PDS - 63.5 pg/ml, p>0.05). Urine excretion of HVA in patients with PDS - 6.63 mg/24 h (p<0.05) was higher than in heathy subjects - 5.65 mg/24 h (p<0.05) and those with EPS - 5.07 mg/24 h (p<0.001). In the group with PDS severity of dyspeptic symptoms showed a positive correlation with the DA concentration in plasma and HVA excretion in the urine.

Increased secretion of DA may play a significant role in the pathogenesis of PDS.