title: Segmental heterogeneity in Bcl-2, Bcl-xL and Bax expression in rat tubular epithelium after ischemia-reperfusion.
abstract: OBJECTIVE
  Studies in rats with bilateral clamping of renal arteries showed transient Bcl-2, Bcl-xL and Bax expression in renal tubular epithelium following ischemia-reperfusion. However, current data on the preferential localization of specific mRNAs or proteins are limited because gene expression was not analysed at segmental level. This study analyses the mRNA expression of Bcl-2, Bcl-xL and Bax in four segments of proximal and distal tubules localized in the renal cortex and outer medulla in rat kidneys with bilateral renal clamping for 30 min and seven reperfusion times versus control animals without clamp.
  
  
  METHODS
  Proximal convoluted tubule (PCT), distal convoluted tubule (DCT), proximal straight tubule (PST) and medullary thick ascending limb (MTAL) were obtained by manual microdissection. RT-PCR was used to analyse mRNA expression at segmental level.
  
  
  RESULTS
  Proximal convoluted tubule and MTAL showed early, persistent and balanced up-regulation of Bcl-2, Bcl-xL and Bax, while PST and DCT revealed only Bcl-2 and Bcl-xL, when only Bax was detected in PST. DCT expressed Bcl-xL initially, and persistent Bcl-2 later.
  
  
  CONCLUSIONS
  These patterns suggest a heterogeneous apoptosis regulatory response in rat renal tubules after ischemia-reperfusion, independently of cortical or medullary location. This heterogeneity of the expression patterns of Bcl-2 genes could explain the different susceptibility to undergo apoptosis, the different threshold to ischemic damage and the different adaptive capacity to injury among these tubular segments.
authors.affiliation: Division of Nephrology, Juan Canalejo University Hospital, A Coruña, Spain. franvalc@terra.es
authors.forename: Francisco
authors.initials: F
authors.lastname: Valdés
authors.forename: Eduardo
authors.initials: E
authors.lastname: Pásaro
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Díaz
authors.forename: Alberto
authors.initials: A
authors.lastname: Centeno
authors.forename: Eduardo
authors.initials: E
authors.lastname: López
authors.forename: Sandra
authors.initials: S
authors.lastname: García-Doval
authors.forename: Severino
authors.initials: S
authors.lastname: González-Roces
authors.forename: Alfonso
authors.initials: A
authors.lastname: Alba
authors.forename: Blanca
authors.initials: B
authors.lastname: Laffon
mesh_terms: D000818:Animals; D017209:Apoptosis; D003250:Constriction; D004195:Disease Models, Animal; D004848:Epithelium / Q000378:metabolism; D007686:Kidney Tubules, Distal / Q000378:metabolism* / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012077:Renal Artery / Q000601:surgery; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D015854:Up-Regulation; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism*; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: C494828:Bax protein, rat; C494813:Bcl2l1 protein, rat; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein