Role of the mesolimbic dopamine system in cardiovascular homeostasis. Stimulation of the ventral tegmental area modulates the effect of vasopressin on blood pressure in conscious rats.

1. The possible role of the ventral tegmental area (VTA) and its dopaminergic projections in cardiovascular regulation is reviewed. 2. Our own work has shown that stimulation of the VTA by local microinjection of the substance P analogue DiMe-C7 caused an increase in blood pressure. The mechanism of the pressor response was an interaction of central dopaminergic activation, most likely at the level of the baroreflex, with the circulatory actions of vasopressin. 3. These findings are important for a possible role of the mesolimbic dopamine system in cardiovascular homeostasis. Several studies reviewed here show that neuronal activity of the VTA and its mesolimbic projections is altered by changes in blood pressure, salt and electrolyte balance, stress and food and water intake. 4. The VTA and mesolimbic dopamine system, while playing a widely accepted role in locomotor activity, cognition and reward mechanisms, may also be involved in the integration of sensory and behavioural information with cardiovascular homeostasis.