The Effect Of Deferoxamine On STH-Ⅱ Solution On Isolated Heart Cold Storage In Rats And The Role Of HIF-1α In It

Objective The aim of this study was to evaluate a possible protective effect ofdeferoxamine (DFO) as an additive agent to St.Thomas No.2(STH Ⅱ)preservation solution on isolated heart cold ischemia injury in rats, and toinvestigate its effect on the regulation of HIF-1α, exploring the potentialmechanism for providing new myocardial protection measure.Methods Forty male SD rats were divided randomly into4groups equally: N,C, D50, D100. N was blank control group. C is experimental control group. Thepreservation solution in D50was supplemented with50μM of DFO and that inD100was supplemented with100μM of DFO. The donor hearts werecardioplegically arrested with20ml STH Ⅱcardioplegia by retrogradeabdominal aorta perfusion in all animals and the hearts were removed. Hearts ingroup N were not received4°C cold storage (CS). Hearts in group C weresubjected to CS at4°C in STH Ⅱ solution for4h. Hearts in groupD50andD100were stored in STH Ⅱsolutions supplemented with50μM and100μM ofDFO respectively. Supernatant of STH Ⅱsolution which stored hearts at4°Cwas collected for measurements of creatine kinase (CK) and lactatedehydrogenase (LDH) leakage in latter three groups. Sections were taken atone-third of the distance from the base to the apex of hearts and stained withhaematoxylin and eosin (HE). Tissue around apexes, weighing about200mgwas taken and stored at80°C for measurements of malondialdehye (MDA) level and the expression of HIF-1α mRNA.Results (1) Myocardial enzymes leakage evaluation: CK leakage in group C,D50and D100was64.56±26.07,40.45±10.68,27.23±10.12(U/L) respectively.LDH leakage in group C, D50and D100was24.10±6.61,15.20±3.39,10.80±3.33(U/L) respectively. Myocardial CK and LDH leakage in group D50and D100was significantly lower than that in group C(P <0.05). CK and LDHleakage in group D100was significantly lower than that in group D50(P<0.05).(2)The iron levels evaluation: The iron content in group N, C, D50andD100was26.55±3.83,20.64±1.61,16.25±1.27and12.70±1.97(μmol/L)respectively. The iron content in group C, D50and D100was significantlylower than that in group N (P <0.05). The iron content in group D50and D100was significantly lower than that in group C (P <0.05). The iron content ingroup D100was significantly lower than that in group D50(P <0.05).(3)TheMDA levels evaluation: The MDA content in group N, C, D50and D100was1.44±0.11,2.08±0.21,1.82±0.14and1.42±0.20(nmol/ml) respectively. TheMDA content in group C and D50was significantly higher than that in group N(P <0.05), but there was no statistical significance between group D100and N(P>0.05). The MDA content in group D50and D100was significantly lowerthan that in group C (P <0.05). The MDA content in group D100wassignificantly lower than that in group D50(P <0.05).(4)The relative expressionof HIF-1α mRNA: The HIF-1α mRNA relative expression in group N, C, D50and D100was0.9621±0.0604,1.3565±0.0355,1.8058±0.1055and2.7948±0.0849respectively. The expression of HIF-1α mRNA in group C, D50 and D100was significantly higher than that in group N (P <0.05). Theexpression of HIF-1α mRNA in group D50and D100was significantly higherthan that in group C (P <0.05). The expression of HIF-1α mRNA in groupD100were significantly higher than that in group D50(P <0.05).(5)Histopathological analysis and damage score: The damage score in groupN,C, D50and D100was0.00±0.00,1.00±0.00,0.95±0.07and0.93±0.07respectively. The damage score in group C, D50and D100was significantlyhigher than that in group N (P <0.05). Compared with group C, the scoredecreased in group D50and D100, but the difference was not statisticallysignificant (P>0.05). Compared with group D50, there was no statisticalsignificance in group D100(P>0.05).(6)Correlation analysis: Theconcentration of iron had positive correlation with myocardial enzymes (CKand LDH) leakage (r=0.587, P <0.01; r=0.670, P <0.01respectively); Therewas a significant positive correlation between the concentration of iron andMDA levels (r=0.779， P <0.01).Conclusions Deferoxamine improved the protective effect of STH Ⅱsolutionon isolated heart cold ischemia injury in rats. The protective potential of DFOpresumably is due to①reducing Fe3+in hearts, inhibition lipid peroxidation②up-regulation of HIF-1α mRNA expression, increasing tolerance to ischemia.