Importance of Adrenergic Neuronal Uptake in Termination of Action: some Aspects

Abstract

The importance of adrenergic neuronal uptake for the function of precapillary resistance vessels is discussed. These vessels constitute a key point in circulatory control. It is here that extensive and precise neurogenic adjustments occur and both the onset and termination of their response to vasoconstrictor fiber activity take place quite promptly to allow for the rapid circulatory adjustments seen, e.g., upon changing body position. Re-uptake of the adrenergic transmitter is evidently crucial for the prompt termination of neurogenic resistance vessel responses. Also the transmitter action seems to be strictly bound to its site of release, which is confined to the adventitial surface of the outer smooth muscle layer. Transmitter re-uptake appears to provide the neurogenic control with the necessary speed of action.