Study on acute ischemia of cervical medulla caused by ligation of unilateral vertebral artery in rabbits

English Keywords:Vertebral artery injury  Vertebral artery ligation  Ischemia  Zoopery  Japanese white rabbit

English Abstract:

  【Abstract】 Objectives: To ligate the vertebral artery based on the comparative anatomy between rabbit and human, and to investigate the changes in cervical spinal cord ischemia in acute phase in order to study the effect of vertebral artery injury made on cervical spinal cord. Methods: The rabbits were randomly divided into experimental group and control group equally. After ligating the first part of right vertebral artery in rabbits in grouping, ex vivo evaluation was carried out at 2 hours after ligation, 6 hours after ligation and 24 hours after ligation. The ex vivo observation indexes were immunohistochemistry, Western Blotting and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) focus on BCL2-associated X protein (BAX), B-cell lymphoma 2(BCL2), cysteine-aspartic protease 3(CASP3) and Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog (FOS). Results: According to the results of immunohistochemically staining and Western Blotting test on the cervical spinal cord of rabbits in ligation groups, protein BAX, BCL2, CASP3 and FOS expressed significantly highly than those in the control group(P<0.05). The maximums of BAX (immunohistochemically staining 39975.00±1007.00; Western Blotting test 3.81±0.04) and BCL2 (immunohistochemically staining 49865.00±1783.00; Western Blotting test 5.26±0.07) were at 24 hours, the maximum of CASP3(immunohistochemically staining 82218.00±1256.00; Western Blotting test 3.46±0.08) was at 6 hours and the maximum of FOS (immunohistochemically staining 23840.00±1584.00; Western Blotting test 2.46±0.04) was at 2 hours after surgery. And the levels of these proteins were different from each other at three time points(P<0.05). BAX and BCL2 increased with time, CASP3 increased at the beginning and later on decreased, FOS decreased with time. qRT-PCR test showed that the mRNA levels of BAX, BCL2, CASP3 and FOS in ligation groups were higher than those in the control group and the differences were statistically significant(P<0.05). The maximums of BAX(14.48±1.16) and BCL2(10.35±1.67) were at 24 hours, the maximum of CASP3(30.37±2.27) was at 6 hours and the maximum of FOS(15.65±1.21) was at 2 hours after surgery. The levels of these mRNAs were different from each other at three time points(P<0.05). BAX and BCL2 increased with time, CASP3 increased at the beginning and later on decreased, FOS decreased with time. Conclusions: The cervical spinal cord experienced a process of obtaining mild acute ischemic injury at the beginning and then quickly recovering along with time according to immunohistochemically staining results, Western Blotting results and qRT-PCR results. The most serious damaged time point was at 6 hours after ligation and the cervical spinal cord returned to baseline by 24 hours after ligation.