title: Effect of phosphorus on endogenous calcium losses during total parenteral nutrition.
abstract: Intravenous phosphorus can reduce urinary calcium losses in patients receiving total parenteral nutrition (TPN). We investigated the effect of intravenous P on urinary and fecal Ca loss in intravenously fed normal and thyroparathyroidectomized (TPTX) rats to assess the role of parathyroid hormone (PTH) and endogenous fecal Ca losses. Doubling the intravenous P load during TPN decreased urinary Ca losses by 54% (0.299 vs 0.137 mmol/d) in intact rats and by 43% (0.514 vs 0.294 mmol/d) in TPTX rats. Increased P load in normal rats had no effect on urinary cyclic AMP excretion, serum Ca, serum P, serum 1,25-dihydroxycholecalciferol, or endogenous fecal Ca losses. These observations suggest that the hypocalciuric effect of P during TPN is independent of PTH and is not caused by a repartitioning of obligatory Ca losses from the renal to the intestinal route.
authors.affiliation: Section of Gastroenterology, Department of Medicine, University of Chicago, IL.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wood
authors.forename: M D
authors.initials: MD
authors.lastname: Sitrin
authors.forename: I H
authors.initials: IH
authors.lastname: Rosenberg
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D000242:Cyclic AMP / Q000652:urine; D004305:Dose-Response Relationship, Drug; D005243:Feces; D008297:Male; D010280:Parathyroid Glands / Q000502:physiology; D010281:Parathyroid Hormone / Q000502:physiology; D010289:Parenteral Nutrition, Total; D010758:Phosphorus / Q000097:blood / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013965:Thyroidectomy
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D000242:Cyclic AMP; D002117:Calcitriol; D002118:Calcium