cardiovascular-agents and Uremia

Topics: Antihypertensive Agents; Arterioles; Arteriosclerosis; Basement Membrane; Bone Remodeling; Calcinosis; Calcium; Cardiovascular Agents; Cardiovascular Diseases; Chronic Kidney Disease-Mineral and Bone Disorder; Diagnostic Tests, Routine; Disease Progression; Humans; Hyperparathyroidism; Hypertension; Hypertrophy, Left Ventricular; Kidney Transplantation; Osteoblasts; Renal Dialysis; Uremia; Vascular Diseases; Venules; Vitamin D

Uremia is often associated with alterations in calcium metabolism and vascular smooth muscle function in hypertension and atherosclerosis. The ways in which these conditions inter-relate are not clearly understood. In order to study the possibility that circulating factors might influence smooth muscle function, experiments were performed on rat aortic strips. The serum from both uremic patients and rats enhanced the norepinephrine-induced contraction (NEIC) and net 45-calcium uptake in rat aortic strips. In a similar manner, the serum of parathyroidectomized uremic rats also increased the NEIC, whereas verapamil reduced the aortic response to levels below those of the control, in the presence of uremic serum. These findings suggest that in both chronic (patients) and early (rats) stages of uremia, there is a circulating factor, different from parathyroid hormone, that affects calcium uptake and vascular smooth muscle contraction.

Topics: Adult; Animals; Aorta, Thoracic; Biological Transport, Active; Calcium; Cardiovascular Agents; Female; Humans; In Vitro Techniques; Male; Muscle Contraction; Muscle, Smooth, Vascular; Norepinephrine; Parathyroidectomy; Rats; Rats, Inbred Strains; Uremia