Preconditioning with oxygen attenuates rat renal ischemia-reperfusion injury.
BACKGROUND
Short time pretreatment with oxygen is reported to be protective against subsequent ischemia-reperfusion (IR) injury of heart and spinal cord in some animal models. The purpose of this study was to investigate the effects of pre-exposure to hyperoxic environment on rat renal IR injury for the first time.


METHODS
The effects of 1 h/d pretreatment with oxygen (>or=95%) for 5 days on a right nephrectomized rat model of renal IR injury was investigated by comparing creatinine clearance, fractional excretion of sodium, plasma creatinine, blood urea nitrogen, and histological injury scores among three groups: IR (40 min ischemia-24 h reperfusion), sham (no IR), and hyperoxia (5 days intermittent pretreatment with oxygen + IR).


RESULTS
Intermittent pretreatment with oxygen resulted in significant improvement of creatine clearance and fractional excretion of sodium (P <or= 0.05). Plasma creatinine above 175 micromol/L or blood urea nitrogen beyond 26 mmol/L was significantly less frequent in hyperoxia than IR group (P < 0.05). Jablonski histological injury score was also significantly lower in hyperoxia compared to IR group (P < 0.05) and hyperoxic preconditioning significantly reduced the frequency of massive proximal tubular necrosis (12.5% versus 75%, P < 0.05).


CONCLUSIONS
The present findings demonstrate that intermittent pre-exposure to hyperoxic environment can reduce subsequent renal IR injury.
Rasoulian
Bahram
B
Research Center for Trauma, Baqiyatallah University of Medical Sciences, Tehran, Iran. rasoulian@irimc.org
Mohammadhosseniakbari
Hassan
H
Kadkhodaee
Mehri
M
Mofid
Mahmood
M
Baqeri
Gholamreza
G
Bigdeli
Mohammad Reza
MR
Ghasemi
Asghar
A
Mohebbi
Hassan Ali
HA
Asgari
Alireza
A
Khoshbaten
Ali
A
D000818:Animals; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood; D004195:Disease Models, Animal; D005740:Gases / Q000627:therapeutic use*; D019194:Ischemic Preconditioning / Q000379:methods; D007668:Kidney / Q000098:blood supply*; D007674:Kidney Diseases / Q000517:prevention & control*; D008297:Male; D010100:Oxygen / Q000627:therapeutic use*; D010102:Oxygen Inhalation Therapy; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D012964:Sodium / Q000652:urine
D005740:Gases; D012964:Sodium; D003404:Creatinine; D010100:Oxygen