title: Minor influence of parathyroid hormone on fractional tubular reabsorption of phosphate in chronic renal failure.
abstract: In untreated patients with chronic renal failure and glomerular filtration rates (GFR) between 10 and 25 ml/min the decrease in fractional tubular reabsorption of phosphate was correlated to the degree of secondary hyperparathyroidism. This correlation was not found in patients with GFR below 10 ml/min. During treatment with 1alpha-hydroxycholecalciferol for 11 weeks: a) serum parathyroid hormone concentration decreased in all patients on average 60%, and was normal in 5 patients after treatment b) fractional tubular reabsorption of phosphate decreased significantly (on average 0.21) c) glomerular filtration rate decreased significantly (on average 27.5%). Since the reduction (or normalization) of serum parathyroid hormone concentration did not increase the fractional tubular reabsorption of phosphate, other (GFR-related) factors than parathyroid hormone play the major role for renal handling of phosphate in chronic renal failure when GFR is below 25 ml/min.
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D005919:Glomerular Filtration Rate; D006801:Humans; D006887:Hydroxycholecalciferols / Q000494:pharmacology* / Q000627:therapeutic use; D006962:Hyperparathyroidism, Secondary / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism*
chemical_list: D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D010710:Phosphates