Psychosocial and central nervous influences in primary hypertension.

A variety of "emotional" response patterns can be elicited at the limbic-hypothalamic level by challenging environmental stimuli, and such mechanisms may contribute to the multifactorial etiology of primary hypertension. The "defense reaction" is of particular interest because of its widespread neurohormonal excitatory influences and frequent, although mild, engagement in daily life events. Evidence is presented showing how common genetic variants of primary hypertension, both in man and spontaneously hypertensive rats, are characterized by a genetically linked central hyperreactivity to psychosocial stimuli. As a result, the previously mentioned central response pattern--with its differentiated excitatory and tropic effects that also involve salt-volume regulation--is more commonly elicited by even trivial environmental stimuli, therefore constituting an important triggering influence in these variants of primary hypertension. Also discussed is the potential genetic nature of this central hyperreactivity and, further, how it interacts with other genetic-environmental influences and with the early induction of structural cardiovascular adaptation, by which the entire system is gradually reset to operate at a raised pressure equilibrium.