The Protective Effects Of HOE-140 On The Cardiac Injury Induced By Doxorubicin In Rats And The Underlying Mechanism

Objective: Doxorubicin(DOX)is one of the most commonly used anthracyclines for the treatment of hematologic and solid tumors,but the severe cardiotoxicity limits its clinical use.Current studies have shown that DOX-induced cardiotoxicity can be attributed to oxidative stress,calcium overload,apoptosis and mitochondrial damage.Many evidences suggest that the occurrence of myocardial infarction,hypertension,heart failure and other diseases is related to the dysfunction of kallikrein activity.Therefore,this study is aimed to study the effect of HOE-140,a bradykinin receptor antagonist,on acute heart injury induced by DOX in rats and its underlying mechanisms.Methods: 40 healthy male SD rats weighting 250g-350 g were selected and randomly divided into 4 groups: blank control(Con)group,DOX group,HOE-140 low-dose + DOX group and HOE-140 high-dose + DOX group.All groups were injected a single dose of DOX(20 mg/kg)intraperitoneally except the Con group,which was given equal amount of saline.Rats in HOE-140 low-lose and high-dose group were given HOE-140 120μg/kg and 180μg/kg respectively by intraperitoneal injection(once a day for three consecutive days).The other two groups were injected with the same volume of saline.The general physical condition of the animals was observed daily,and the electrocardiography(ECG)and ultrasonic cardiogram were performed on the third day.After that,the abdominal cavities were opened,and blood was taken from the abdominal aorta and centrifuged,then various biochemical indexes(CK,LDH,and CK-MB)in serum were measured.The heart was weighed and the heart coefficients were calculated by dividing the body weight of the animal.Some of the heart tissues were taken for histopathological examination and Electron microscopic observation,m RNA expression levels of BAX and IL-1 were detected by q PCR,and protein expression levels of BAX,bcl-2 and TNF-αwere detected by Western Blot.Results:1.General condition of animals.The body weight was decreased in all the other groups Compared with Con group.The animals showed decreased food intake,bristles,cold limbs,and weight loss in DOX group compared with those in Con group(P<0.05).The general condition of the animals in HOE-140 group were better than those in DOX group,and the body weight was significantly increased in high-dose group(P<0.05).2.Serum biochemical results.Compared with Con group,the levels of CK,CK-MB and LDH in serum were all increased in DOX group(P < 0.05 or < 0.01).Compared with DOX group,the levels of CK and LDH were significantly decreased in the HOE-140 low-dose group(P<0.05 respectively).And the levels of CK and CK-MB were significantly decreased in HOE-140 high-dose group compared with those in DOX group(P<0.05).3 ECG results.Compared with Con group,both QRS duration and QT interval in DOX group were prolonged(P<0.05 or 0.01 respectively),and the R-R interval was increased(P<0.05).Compared with DOX group,Only QT intervals were significantly recovered in both low and high-dose of HOE-140 group(P<0.05 respectively).4.Ultrasonic cardiogram results.Compared with Con group,the heart rate,stroke volume and cardiac output of rats in the DOX group were all decreased(P<0.01 or 0.05).Compared with DOX group,cardiac output was significantly increased in HOE-140 high-dose group(P<0.05),and no statistical difference was found in other indexes.5.Myocardial histopathological and electron microscopic findings.Myocardial histopathological results: The cardiac cells of Con group were arranged orderly.Muscle fibers were broken,interstitial edema and congestion,accompanied by a large number of inflammatory cells infiltration were found in DOX group.HOE-140 can relieve the inflammatory cell infiltration and congestion caused by DOX to different degrees in each dose group.Electron microscopic findings: There was no abnormal finding in Con group.Oedema and membrane fusion of mitochondria,consolidation of nuclear and sarcomere arrangement disorder were found in DOX group.The edema and membrane fusion of mitochondria caused by DOX were alleviated to different degrees in HOE-140 low and high doses group.6.SOD and MDA detection in cardiac tissue.Compared with Con group,SOD content was decreased,while MDA content was increased in the myocardial tissue of DOX group(P <0.01 respectively).Compared with DOX group,SOD level had no obvious change while MDA level was decreased in HOE-140 low-dose group,and SOD level was increased while MDA level was decreased(P <0.01)in myocardial homogenate in HOE-140 high-dose group(P <0.01).7 q PCR results.The m RNA levels of BAX and IL-1β in DOX group were significantly higher than those in Con group(P <0.05 respectively).Compared with DOX group,the m RNA levels of BAX in HOE-140 groups were significantly reduced(P <0.01),and the m RNA level of IL-1β in HOE-140 high-dose group was significantly decreased(P <0.05).8 Western Blot results.Compared with Con group,the content of TNF-α protein in DOX group was significantly increased(P<0.01),and the BAX/BCL-2 ratio was also significantly increased(P <0.01).Compared with DOX group,the content of TNF-α protein was significantly decreased in HOE-140 low-dose group(P <0.05),and the ratio of BAX/BCL-2 was also significantly decreased(P <0.01).Compared with DOX group,the contents of TNF-α protein and the ratio of BAX/CL-2 were significantly reduced in HOE 140 high-dose group(P <0.01 respectively).Conclusions:1.DOX can cause acute heart injury in rats,which is related to the increased heart oxidative stress,inflammation and apoptosis.2.HOE-140 can alleviate acute heart injury induced by DOX in rats,and its mechanism is related to reducing oxidative stress,apoptosis and inflammation.