title: Vitamin A losses during continuous ambulatory peritoneal dialysis.
abstract: Since continuous ambulatory peritoneal dialysis (CAPD) causes losses of certain plasma proteins and their ligands, we examined the serum concentrations of vitamin A and retinol-binding protein (RBP), as well as the concentrations of vitamin A in the skin and dialysis fluid from 32 patients on CAPD over a period of 1-30 months (mean 7.5). The mean values of vitamin A and RBP in serum were 2-4 times higher than those in the healthy controls; a consistent finding in patients with chronic renal failure. Similarly, the vitamin A concentrations in skin were elevated in the CAPD patients (p less than 0.01). The vitamin A content of the dialysate (mean 1.4 mumol/24 h), which correlated significantly with the serum vitamin A concentration (r = 0.67), was constant during CAPD treatment. RBP was present in the dialysate and its concentration closely correlated with that of vitamin A (r = 0.95), indicating that the transperitoneal diffusion involved retinol-RBP. This conclusion was supported by calculations of clearance rates. Despite the considerable losses of vitamin A in CAPD fluid, the patients' vitamin A concentrations in serum and skin remained elevated. Whether extended CAPD treatment (greater than 30 months) may eventually affect the vitamin A situation in chronic renal failure warrants further observations.
mesh_terms: D001693:Biological Transport, Active; D003928:Diabetic Nephropathies / Q000378:metabolism / Q000628:therapy; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism* / Q000628:therapy; D008297:Male; D010529:Peritoneal Cavity / Q000378:metabolism; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects*; D012177:Retinol-Binding Proteins / Q000378:metabolism; D054839:Retinol-Binding Proteins, Plasma; D012867:Skin / Q000378:metabolism; D013997:Time Factors; D014801:Vitamin A / Q000378:metabolism*
chemical_list: D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A