title: STIM1fl/fl Ksp-Cre Mouse has Impaired Renal Water Balance.
abstract: OBJECTIVE
  STIM1 is as an essential component in store operated Ca2+ entry. However give the paucity of information on the role of STIM1 in kidney, the aim was to study the function of STIM1 in the medulla of the kidney.
  
  
  METHODS
  we crossed a Ksp-cre mouse with another mouse containing two loxP sites flanking Exon 6 of STIM1. The Ksp-cre mouse is based upon the Ksp-cadherin gene promoter which expresses cre recombinase in developing nephrons, collecting ducts (SD) and thick ascending limbs (TAL) of the loop of Henle.
  
  
  RESULTS
  The offspring of these mice are viable without gross morphological changes, however, we noticed that the STIM1 Ksp-cre knockout mice produced more urine compared to control. To examine this more carefully, we fed mice low (LP) and high protein (HP) diets respectively. When mice were fed HP diet STIM1 ko mice had significantly increased urinary volume and lower specific gravity compared to wt mice. In STIM1 ko mice fed HP diet urine creatinine and urea were significantly lower compared to wt mice fed HP diet, however the fractional excretion was the same.
  
  
  CONCLUSIONS
  These data support the idea that STIM1 ko mice have impaired urinary concentrating ability when challenged with HP diet is most likely caused by impaired Ca2+-dependent signal transduction through the vasopressin receptor cascade.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Division of Nephrology, University of Maryland, Baltimore, USA.
authors.forename: Liudmila
authors.initials: L
authors.lastname: Cebotaru
authors.forename: Valeriu
authors.initials: V
authors.lastname: Cebotaru
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Lois J
authors.initials: LJ
authors.lastname: Arend
authors.forename: William B
authors.initials: WB
authors.lastname: Guggino
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood / Q000652:urine; D003404:Creatinine / Q000097:blood / Q000652:urine; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology; D007668:Kidney / Q000378:metabolism*; D007671:Kidney Concentrating Ability / Q000235:genetics; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D018345:Mice, Knockout; D008822:Mice, Transgenic; D051437:Renal Insufficiency / Q000235:genetics / Q000378:metabolism; D000071737:Stromal Interaction Molecule 1 / Q000235:genetics / Q000378:metabolism*; D014508:Urea / Q000097:blood / Q000652:urine; D014554:Urination / Q000187:drug effects; D014867:Water / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000235:genetics
chemical_list: D004044:Dietary Proteins; C100757:Stim1 protein, mouse; D000071737:Stromal Interaction Molecule 1; D014867:Water; D014508:Urea; D003404:Creatinine; C521052:Kif11 protein, mouse; D016547:Kinesins; D002118:Calcium