title: Control of peripheral vascular resistance: evidence based on the in vitro study of resistance arteries.
abstract: Resistance arteries, mainly small muscular arteries and arterioles, control the distribution of the cardiac output, capillary flow, pressure, and exchange. The active tone of these small vessels is influenced by a large variety of factors. Some less well known factors are discussed, including myogenic tone, variation in alpha 1-adrenoceptor number and affinity, and synaptic cleft width. The implications are that the adrenergic transmitter might be acting on low affinity non-alpha-adrenoceptors--extraceptors; that long-term trophic effects influence not only the function of blood vessels, but their number; and that a variety of types of vasodilator nerves exists. The adrenergic synaptic mechanism is different in small, compared with larger arteries; in particular there is an increased role of uptake. It is not known whether these influences are changed in hypertension.
authors.affiliation: University of Vermont, Department of Pharmacology, College of Medicine, Burlington 05405.
authors.forename: J A
authors.initials: JA
authors.lastname: Bevan
mesh_terms: D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D008833:Microcirculation; D009119:Muscle Contraction / Q000187:drug effects; D009129:Muscle Tonus; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology* / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000648:ultrastructure; D009638:Norepinephrine / Q000097:blood / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D014655:Vascular Resistance; D014664:Vasodilation
chemical_list: D011942:Receptors, Adrenergic, alpha; D009638:Norepinephrine