Role of heat stress response in the tolerance of immature renal tubules to anoxia.
The stress response was studied in suspensions of tubules from immature (IT) and mature (MT) rats after noninjury, heat, oxygen, and anoxia. Under all conditions, IT exhibited more exuberant activation of heat shock transcription factor (HSF) than MT. Characterization of activated HSF in immature cortex revealed HSF1. Also, 2 h after each condition, heat shock protein-72 (HSP-72) mRNA was twofold in IT. As the metabolic response to 45 min of anoxia, 20-min reoxygenation was assessed by measuring O2 consumption (O2C). Basal O2C was manipulated with ouabain, nystatin, and carbonylcyanide p-chloromethyoxyphenylhydrazone (CCCP). Basal O2C in IT were one-half the value of MT. After anoxia, basal O2C was reduced by a greater degree in MT. Ouabain reduced O2C to half the basal value in both noninjured and anoxic groups. Basal O2C was significantly stimulated by nystatin but not to the same level following anoxia in MT and IT. Basal O2C was also stimulated by CCCP, but after anoxia, CCCP O2C was significantly less in MT with no decrease in IT, suggesting mitochondria are better preserved in IT. Also, O2C devoted to nontransport activity was better maintained in IT.
Gaudio
K M
KM
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Thulin
G
G
Mann
A
A
Kashgarian
M
M
Siegel
N J
NJ
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D015687:Cell Hypoxia / Q000502:physiology*; D004272:DNA, Mitochondrial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004586:Electrophoresis; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009761:Nystatin / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010101:Oxygen Consumption; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014157:Transcription Factors / Q000378:metabolism
D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; C000619709:Hsf1 protein, rat; D012333:RNA, Messenger; D014157:Transcription Factors; D009761:Nystatin; C070389:HSF2 protein, human; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D010042:Ouabain