A Study Of Cell Damage Associated With PARP-1 On The Brain Injury Mechanism After Cardiopulmonary Bypass

PurposeThe experimental model of brain injury in Chinese male miniature pigs after deep hypothermia circulatory arrest was established,and the degree of central nervous system injury was judged by neurological injury scale.The location and materials of brain injury were determined by DWI technique.Frozen sections and paraffin sections were made.The results of HE staining,electron microscopy staining and PARP-1 immunohistochemical staining were observed by microscope.Therefore,the role of PARP dependent cell injury in brain injury after cardiopulmonary bypass(CPB)was clarified,and a new idea was provided for the prevention and treatment of brain injury after cardiopulmonary bypass(CPB).MethodsThe experiment was approved by the animal ethics committee.1.Fifteen Chinese male miniature pigs were selected and divided into two groups:control group(n =5),experimental group(n = 5),cardiopulmonary bypass group(n=5)and deep hypothermic circulatory arrest group(n = 5).The control group was given general anesthesia and was not subjected to cardiopulmonary bypass(CPB);The cardiopulmonary bypass group was the same as the cardiopulmonary bypass group except for the deep hypothermia operation.Deep hypothermia circulatory arrest operation,postoperative ECG monitoring,circulation support of dopamine and other vasoactive drugs to ensure the survival of experimental animals.2.Animal model DWI images:On the first day before operation,the brain DWI of all the animals was used as the control to exclude the original brain injury foci of the experimental animals.After the operation of 2 days,DWI examination of the living animal brain was performed again,and the neurobehavioral scores were evaluated before,1 day and 2 days after operation.3.The brain tissues of the experimental group were examined by pathology:He staining,electron microscope examination,TUREL detection and PARP-1 immunohistochemistry.Results1.Nuclear pyknosis was triangular or polygonal in deep hypothermic circulatory arrest group,and the expression of eosin stained par in chromatin was significantly higher than that in control group and cardiopulmonary bypass group.2.Electron microscopic staining:In deep hypothermia circulatory arrest group,such phenomena as nuclear pyknosis,nuclear membrane invagination,chromatin edge aggregation,mitochondria change,swelling,vacuolar degeneration,irregular cristaeand cristae rupture were more obvious than those in control group and cardiopulmonary bypass group.3.Tunel staining can be seen:The number of brown staining positive cells in deep hypothermia circulatory arrest group was significantly higher than that in control group,and the number of swollen neurons and atrophy neurons with nuclear pyknosis and nuclear fragmentation were significantly higher than those in control group and cardiopulmonary bypass group.4.PARP-1 immunohistochemical staining:Nuclear pyknosis was triangular or polygonal in deep hypothermic circulatory arrest group,and the expression of eosin stained par in chromatin was significantly higher than that in control group and cardiopulmonary bypass group.Conclusion1.The increase of PARP-1 activity and cell necrosis and/or apoptosis play an important role in the molecular mechanism of brain injury after cardiopulmonary bypass.2.The results of the experiment provide the basis for the latest research results of brain injury to be applied in this field in a timely manner,which is helpful to the development of brain injury.For the prevention and treatment of brain injury after cardiopulmonary bypass.