Toxicological Effects Of Hexavalent Chromium On The Heart Of Chinese Rural Dogs

This experiment aims to establish a poisoning model of hexavalent chromium（Cr（Ⅵ））in heart of Chinese rural dog.The test records and detects the electrocardiogram within 35d and the myocardial enzyme parameters within 3d.Histopathology,inflammatory factors,oxidation should be changes in indicators such as kinases and ATPase.It provides a reliable data foundation for the study of the mechanism of heavy metal poisoning in Chinese rural dog heart tissue.In this experiment,potassium dichromate（K₂Cr₂O₇）was used as the chromium source of Cr（Ⅵ）,and the adult Chinese dog was challenged with potassium dichromate（K₂Cr₂O₇）to study the toxicological effects of its heart tissue.In the control group and the low（L）,medium（M）,and high（H）dose test groups,the control group did not add potassium dichromate.The additive amount of the test group was 0.92 mg/kg,1.15 mg/kg and 1.38mg/kg.The relative static electrocardiogram of the Chinese rural dog in the prone position was recorded by using a three-channel electrocardiograph standard limb lead.Before the challenge and within 72h after the challenge,the blood was taken from the forearm subcutaneous vein,and the supernatant was centrifuged to detect the myocardial enzyme.The Chinese rural dog was euthanized 35d later,and histological analysis was performed using cardiac tissue.The heart tissue was ground using a homogenizer,and the supernatant was centrifuged to detect inflammatory factors in the heart tissue.The parameters of oxidative kinase,adenosine triphosphatase（ATPase）were measured.The results of the test showed that the electrocardiograms of group H,group M and group L of the 35d test group showed significant ST segment elevation and increased T wave in leads of I,II and III.The H group of the aVF lead showed an increase in T wave.The lead waves of the aVRL group,the M group,and the H group were higher than those of the control group.In the myocardial enzyme spectrum,four myocardial enzymes,aspartate aminotransferase（AST）,phosphocreatine kinase（CK）,and phosphocreatine kinase were co-workers.Enzyme（CK-MB）and lactate dehydrogenase（LDH）showed significant changes after challenge（P<0.05）.The myocardial enzyme content of M group and H group increased significantly with time in the experimental group（P<0.05）.Pathological sections showed only mild lesions in group H,myocardial cell structure was basically normal,cytoplasm was slightly loose,and the arrangement was relatively neat.Oxidative stress index showed that catalase（CAT）and total superoxide dismutase（T-SOD）decreased with increasing Cr（Ⅵ）dose,and malondialdehyde（MDA）content increased with increasing Cr（Ⅵ）dose.Inflammatory factor interleukin-1β（IL-1β）,interleukin Both-8（IL-8）and tumor necrosis factor-α（TNF-α）increased to varying degrees,while IL-10 content decreased with increasing dose of Cr（Ⅵ）.Adenosine triphosphatase（The content of ATPase）also decreased with increasing Cr（Ⅵ）dose.Conclusion:This experiment successfully established a hexavalent chromium Chinese rural dog heart tissue poisoning model,and tested the changes of electrocardiogram,myocardial enzyme parameters,histopathology,inflammatory factors,oxidative kinase and ATPase.The results showed that different concentrations of Cr（Ⅵ）caused different degrees of damage to the heart of the Chinese rural dog,and Cr（Ⅵ）could cause oxidative damage,inflammation and ATPase content in the Chinese rural dog.