title: Electrolyte homeostasis in urothelial neoplasia: the effects of amiloride.
abstract: OBJECTIVE
  To investigate the effect of amiloride preincubation on the intracellular electrolyte levels in neoplastic and non-neoplastic urothelium.
  
  
  METHODS
  Samples of papillary transitional cell carcinomas (grades 1 and 2) and non-neoplastic human urothelium were either frozen immediately or after pre-incubation with Krebs saline alone or with Krebs saline containing amiloride. The frozen samples were planed in a cryo-ultramicrotome and then examined by low temperature scanning electron microscopy. Intracellular electrolyte levels were measured using X-ray microanalysis.
  
  
  RESULTS
  In the cells frozen immediately the ratios K+/Na+, K+/P and K+/Cl- were significantly increased in neoplastic compared with non-neoplastic urothelial cells (P < 0.001). This difference was also found in the cells pre-incubated with Krebs saline alone but was not present in the cells pre-incubated with amiloride.
  
  
  CONCLUSIONS
  These results were consistent with the concept that activation of the amiloride-sensitive Na+/H+ membrane exchanger is a primary event in neoplasia.
authors.affiliation: Division of Biological Sciences, IEBS, Lancaster University, UK.
authors.forename: M L
authors.initials: ML
authors.lastname: Cartman
authors.forename: J A
authors.initials: JA
authors.lastname: Morris
authors.forename: H
authors.initials: H
authors.lastname: Huddart
authors.forename: W G
authors.initials: WG
authors.lastname: Staff
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000584:Amiloride / Q000378:metabolism / Q000627:therapeutic use*; D002295:Carcinoma, Transitional Cell / Q000378:metabolism*; D002713:Chlorine / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D005260:Female; D006487:Hemostasis; D006801:Humans; D017136:Ion Transport; D008297:Male; D008875:Middle Aged; D010758:Phosphorus / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D014571:Urologic Neoplasms / Q000188:drug therapy / Q000378:metabolism*
chemical_list: D010758:Phosphorus; D002713:Chlorine; D000584:Amiloride; D012964:Sodium; D011188:Potassium