title: The use of hydroxy-DL-proline-2-(14)C in the investigation of hydroxyproline metabolism in normal subjects and in patients with renal insufficiency.
abstract: The metabolism of hydroxyproline was investigated in six healthy subjects and four patients with chronic renal insufficiency (creatinine clearances respectively 40, 10, 7, 2 1/2 ml/min). For this purpose hydroxy-DL-proline-2-(14)C was administered intravenously and the excretion patterns of radio-activity in plasma, urine and expired air (14CO2) were determined. A separation procedure (using thin layer chromatography followed by oxidation with D-amino acid oxidase) made it possible to determine the concentration of hydroxy-L-proline-2-(14)C in the presence of the D-isomer and the degradation products of both. Although the use of a racemic mixture as tracer made conclusions more difficult, it could be shown that in uremic patients the concentration of hydroxy-DL-proline -2-(14)C remained high in the blood for a longer period, the metabolites appeared in the urine later, and the peak respiratory 14CO2 excretion was reached later and was lower than in the healthy subjects. On this basis it was concluded that the metabolism of hydroxyproline is diminished in patients with renal insufficiency.
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism*; D006207:Half-Life; D006801:Humans; D006909:Hydroxyproline / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007676:Kidney Failure, Chronic / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008297:Male; D008657:Metabolic Clearance Rate; D012119:Respiration; D013237:Stereoisomerism
chemical_list: D002250:Carbon Radioisotopes; D002245:Carbon Dioxide; D006909:Hydroxyproline