Patterns of alpha-adrenoceptor regulation of the vasculature.
There are patterns in the distribution of the characteristics of vascular alpha-adrenoceptors. Sudden changes in their mechanism occur at particularly sites along the main branches of the aorta; in some regional vascular beds, but not others, there is a progressive reduction in the response that can be elicited through the alpha-adrenoceptor; in smaller blood vessels, alpha- and beta-adrenoceptors may be spatially separated in the vessel wall; in most blood vessels, the inner smooth muscle is more sensitive to alpha-agonists and more dependent on sequestered calcium than the outer. There is little support for a significant physiological role of the proposed gamma-receptor.
D000818:Animals; D001011:Aorta / Q000294:innervation; D001158:Arteries / Q000294:innervation; D001808:Blood Vessels / Q000294:innervation* / Q000473:pathology; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000294:innervation; D009638:Norepinephrine / Q000502:physiology*; D010646:Phentolamine / Q000494:pharmacology; D011651:Pulmonary Artery / Q000294:innervation; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D013312:Stress, Physiological / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000502:physiology
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D009638:Norepinephrine; D010646:Phentolamine