title: An in vitro model of nephrocalcinosis using rabbit inner medullary collecting tubular cell culture.
abstract: In order to investigate the pathogenesis of medullary nephrocalcinosis, rabbit inner medullary collecting duct cells were grown in media containing different Ca++, PTH and pH levels. It was found that high Ca++ (7.8mM) only reduced growth slightly and that crystalline deposits were found under the cells. This suggests that high Ca++ is not severely toxic to the cells but can lead to deposition of calcium beneath the basement membrane. PTH did not effect cell growth even in the presence of high Ca++ implying that it has an indirect effect on tubular cells in medullary nephrocalcinosis associated with hyperparathyroidism. In renal tubular acidosis these cells are subjected to a persistently high urinary pH and low interstitial pH. Raising the pH reduced the cell growth in normal Ca++ medium whereas lowering the pH increased cell growth in vitro. Our results show that nephrocalcinosis is not due to the direct effect of raised pericellular Ca++ or PTH alone and that persistently alkaline tubular fluid may play a role.
authors.affiliation: Department of Renal Research, Royal Free Hospital, Hampstead, London, UK.
authors.forename: J C
authors.initials: JC
authors.lastname: Senior
authors.forename: J E
authors.initials: JE
authors.lastname: Scoble
authors.forename: Z
authors.initials: Z
authors.lastname: Varghese
authors.forename: P
authors.initials: P
authors.lastname: Sweny
authors.forename: J F
authors.initials: JF
authors.lastname: Moorhead
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D006863:Hydrogen-Ion Concentration; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007685:Kidney Tubules, Collecting / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009397:Nephrocalcinosis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D010281:Parathyroid Hormone / Q000494:pharmacology; D011817:Rabbits
chemical_list: D010281:Parathyroid Hormone; D002118:Calcium