together , this suggests elevated sympathetic activity and enforced vasoconstriction via postjunctional alpha 1-adrenoceptors in essential hypertension . beta-adrenoceptor-mediated cardiovascular responses decrease with age and even more with high blood pressure , which contributes to unopposed alpha-adrenoceptor-mediated vasoconstriction .
C0001638
alpha 1-adrenoceptors
C0034784
alpha-adrenoceptor