Involvement of catecholaminergic neurones of the nucleus of the solitary tract (NTS) in blood pressure regulation.

Determination of the release of catecholamines in the rostral and intermediate aspects of the NTS before, during and after termination of a bilateral carotid occlusion revealed that increases in blood pressure elicited by the occlusion reduce the release rates of noradrenaline and adrenaline, while occlusion-induced decreases in blood pressure diminish the release rate of dopamine. These findings demonstrate that, in response to blood pressure changes elicited by carotid occlusion, in both aspects of the NTS noradrenaline and adrenaline act to increase blood pressure when released from their neurones, while the release of dopamine lowers blood pressure. Noradrenergic neurones of the NTS receive impulses from baroreceptors of carotid sinus and aortic arch.