Mild Hypothermia Protects Renal Function in Ischemia-reperfusion Kidney: An Experimental Study in Mice

Mild hypothermia reduces the damage caused by hypoxia and oxidative stress, but how this happens is not very clear. Mice were anesthetized and their core body temperature was maintained at 38 ± 0.5°C and 32 ± 0.5°C. The renal artery and renal veins were blocked for 35 minutes and reperfusion was performed. Twenty-four hours later, serum was obtained to detect the concentrations of creatinine. The expression of CIRP, TRX, Bcl-2, and Bax were detected in tissue samples using Western blot. Apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and the apoptosis rates were calculated. SOD and MDA were detected to determine the extent of oxidative damage in different groups. The concentration of creatinine in the NC group was 2.11 ± 0.39 mg/dL. Compared to the IR group, the concentration of creatinine decreased in MH+IR group and showed a significant statistical difference (8.74 ± 1.38 mg/dL vs 15.36 ± 2.13 mg/dL, P < .01); the apoptosis rate also decreased with statistical significance (15.02 ± 1.45% vs 37.02 ± 5.70%, P < .01). Compared to the IR group, the expression of CIRP, TRX, and the Bcl-2/Bax ratio significantly increased in the MH+IR group. The SOD activity in the MH+IR group increased (26.90 ± 4.41 U/mgprot vs 16.85 ± 2.41 U/mgprot, P < .05) and the MDA level decreased (0.76 ± 0.18 nmol/mgprot vs 1.37 ± 0.32 nmol/mgprot, P < .05) compared to those of the IR group. Mild hypothermia protects mice kidneys from ischemia-reperfusion damage by reducing oxidative stress injury and apoptosis.