Joseph Zacharia
α1- Adrenoceptors in Small Blood Vessels
The relative importance of the different α1-adrenoceptor subtypes in regulation of peripheral resistance and systemic arterial blood pressure is not clear, as the contribution of different subtypes to vasoconstriction varies with species and resistance vascular bed. A further factor which may influence the subtypes involved in vasoconstriction physiologically is the manner of receptor activation, i.e., whether by circulating catecholamine or by neurally-released noradrenaline. Previous studies on adrenoceptors have suggested a topological difference between postsynaptic α1-adrenoceptor subtypes and sympathetic nerves.