title: Effect of medial calcification on vascular function in uremia.
abstract: The contribution of medial calcification to vascular dysfunction in renal failure is unknown. Vascular function was measured ex vivo in control, noncalcified uremic, and calcified uremic aortas from rats with adenine-induced renal failure. Plasma urea was 16 ± 4, 93 ± 14, and 110 ± 25 mg/dl, and aortic calcium content was 27 ± 4, 29 ± 2, and 4,946 ± 1,616 nmol/mg dry wt, respectively, in the three groups. Maximal contraction by phenylephrine (PE) or KCl was reduced 53 and 63% in uremic aortas, and sensitivity to KCl but not PE was increased. Maximal relaxation to acetylcholine was impaired in uremic aortas (30 vs. 65%), and sensitivity to nitroprusside was also reduced, indicating some impairment of endothelium-independent relaxation as well. None of these parameters differed between calcified and noncalcified uremic aortas. However, aortic compliance was reduced in calcified aortas, ranging from 17 to 61% depending on the severity of calcification. We conclude that uremic vascular calcification, even when not severe, significantly reduces arterial compliance. Vascular smooth muscle and endothelial function are altered in renal failure but are not affected by medial calcification, even when severe.
authors.affiliation: Department of Medicine, Emory University, Renal Div., WMB 338, 1639 Pierce Dr., Atlanta, GA 30322, USA.
authors.forename: Roy L
authors.initials: RL
authors.lastname: Sutliff
authors.forename: Erik R
authors.initials: ER
authors.lastname: Walp
authors.forename: Alexander M
authors.initials: AM
authors.lastname: El-Ali
authors.forename: Stacey
authors.initials: S
authors.lastname: Elkhatib
authors.forename: Koba A
authors.initials: KA
authors.lastname: Lomashvili
authors.forename: W Charles
authors.initials: WC
authors.lastname: O'Neill
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000225:Adenine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects; D002114:Calcinosis / Q000503:physiopathology*; D002118:Calcium / Q000378:metabolism; D003187:Compliance; D004044:Dietary Proteins / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D016226:Phosphorus, Dietary / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012079:Renal Circulation / Q000502:physiology*; D014511:Uremia / Q000503:physiopathology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D004044:Dietary Proteins; D016226:Phosphorus, Dietary; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D011189:Potassium Chloride; D000225:Adenine; D000109:Acetylcholine; D002118:Calcium