The effect of phlebotomy and mannitol on acute renal injury induced by ischemia/reperfusion of lower limbs in rats.
BACKGROUND
Abdominal aortic surgery can cause ischemic/reperfusion (I/R) injury not only in the lower limbs but also in remote organs such as kidneys. Venous blood volume exclusion from the inferior vena cava (phlebotomy) or/and mannitol are used as a treatment for I/R injury of kidney in humans, despite the fact that the effectiveness of these treatments is still debated. The aim of this study was to evaluate the effects of phlebotomy or/and mannitol on rat kidneys in a model of lower limbs I/R-induced acute renal injury (ARI).


METHODS
Thirty male Wistar albino rats were used and divided into five groups: (I) sham-operated group, laparotomy without I/R injury (group [S], n = 6); (II) I/R group, infrarenal aortic cross-clamp was used for lower limbs I/R, 3 hours of ischemia followed by 2 hours of reperfusion (group [I/R], n = 6); (III) I/R + phlebotomy group, identical to group [I/R] except for 1 mL of blood aspiration from the inferior caval vein just after ischemia (group [P], n = 6); (IV) I/R + mannitol-treated group, these rats were subjected to I/R and received a bolus injection of mannitol (group [M], n = 6); and (V) I/R + phlebotomy + mannitol-treated group (group [P + M], n = 6), the same procedures were performed as those described for previous groups. At the end of 2-hour reperfusion, all rats were sacrificed. Both kidneys were harvested for biochemical assay (myeloperoxidase [MPO] and superoxide dismutase [SOD] activities, and malondialdehyde [MDA] and reduced glutathione levels) and for histopathological examination (tubular necrosis and acute inflammation on kidney [ARI score]).


RESULTS
Aortic I/R significantly increased the level of MDA (reflecting lipid peroxidation), SOD (enzymatic endogenous antioxidant), and MPO (reflecting neutrophil infiltration) activity (p < 0.05). Phlebotomy or/and mannitol treatments significantly decreased the level of MDA, SOD, and MPO activity and increased glutathione level (nonenzymatic antioxidant in the kidney tissues) (p < 0.05). Histological evaluation of ARI score showed that aortic I/R significantly increased (p value for group [S] versus group [I/R] was 0.012), whereas phlebotomy or/and mannitol treatments significantly decreased tubular necrosis and inflammatory infiltration (p values for group [I/R] versus group [P], [M], and [P + M] were 0.043, 0.043, and 0.003, respectively).


CONCLUSIONS
This experiment clearly indicated that the lower limbs I/R-induced ARI attenuated significantly by phlebotomy or/and mannitol treatments. Phlebotomy plus mannitol is more effective treatment than phlebotomy or mannitol alone in preventing lower limbs I/R-induced ARI in rats. Further clinical studies are required to clarify whether phlebotomy or/and mannitol treatments are beneficial in alleviating of ARI during abdominal aortic surgery.
Department of Cardiovascular Surgery, School of Medicine, Pamukkale University, Denizli, Turkey. dr.igoksin@hotmail.com
Ibrahim
I
Goksin
Fahri
F
Adali
Yasar
Y
Enli
Metin
M
Akbulut
Zafer
Z
Teke
Gokhan
G
Sackan
Erkin
E
Ocak
Ali Vefa
AV
Ozcan
D058186:Acute Kidney Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D003131:Combined Modality Therapy; D003250:Constriction; D004195:Disease Models, Animal; D005121:Extremities / Q000098:blood supply*; D005978:Glutathione / Q000378:metabolism; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008353:Mannitol / Q000494:pharmacology*; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism; D018962:Phlebotomy; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D008353:Mannitol; D008315:Malondialdehyde; D009195:Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione