The adrenergic neuroeffector interaction in the normotensive and hypertensive blood vessel wall

Abstract

The data available indicate that, in particular, in the spontaneous hypertensive rat, the early stages of the hypertensive process are characterised by a hyperfunction of the peripheral adrenergic nerve varicosities, which results in an enhanced release of adrenergic neurotransmitter; this may be an important factor in increasing peripheral resistance and initiating the hypertension. In sustained hypertension, changes in the disposition of neuronally released norepinephrine have occurred, in particular an acceleration of the neuronal uptake process. This results in a relative reduction of the vasoconstrictor responses to sympathetic nerve stimulation, which compensates in part for the increase in vascular smooth muscle reactivity; this in turn is the consequence of the chronic exposure of the blood vessels to the high blood pressure.