Gastric pressure response to low dose dopamine infusion in normal man

The gastric pressure response to distension was measured during intravenous infusion of dopamine at a rate of 2 mug min(-1)kg(-1) over 2h 50min in 5 normal volunteers to determine whether dopamine at this dose potentiated gastric adaptive relaxation, leading to a fall in gastric pressure and thus a potential delay in gastric emptying. This would be of obvious importance in patients being given dopamine at this dose to support renal function and at the same time being fed by nasogastric tube. The pressure response decreased during the first hour in all five subjects (p < 0.01). In 2 it recovered during the third hour to pre-infusion values, but in 2 it remained diminished; in 1 subject the results were equivocal. Circulating dopamine, noradrenaline and adrenaline concentrations all increased during dopamine (p < 0.05), but compared with control there was no difference in plasma free fatty acids, glycerol, cortisol or glucose concentrations. Dopamine at 2 mug min(-1) kg(-1) produced a transient fall in gastric pressure in all subjects, and a persistent fall in some. The changes in gastric pressures were seen at infusion rates that produced no metabolic or inotropic effects.