Dopamine: a stress modulator in the brain and gut.

1. Central dopamine (DA) exhibits large and rapid responses to stress challenge, particularly in the mesolimbic DA tract and, to a lesser degree, in the mesocortical tract. 2. Over the last few years, there has emerged an increasing role for peripheral DA, especially gastrointestinal DA, as a modulator of gastroduodenal injury consequent to stress exposure. 3. Evidence has accumulated which strongly supports a role for DA as an endogenous gastroprotective element and it appears that the dopaminergic "brain-gut axis" is a critical determinant of gastroduodenal mucosal integrity in the stress-challenged gut.