The Cerebrovascular Endothelial Cell Injury After Cardiopulmonary Bypass In Rats

  • Dr Gang Chen, Cardiovascular Center, Children’s Hospital of Fudan University, China
  • Dr Bing Jia, Cardiovascular Center, Children’s Hospital of Fudan University, China
  • Dr Ye Liu, Department of Pathology, Medical College of Fudan University, China
  • Dr Xiangang Yan, Cardiovascular Center, Children’s Hospital of Fudan University, China
  • Ms Chunlan He, Cardiovascular Center, Children’s Hospital of Fudan University, China
  • Dr Ming Ye, Cardiovascular Center, Children’s Hospital of Fudan University, China
  • Dr Qilin Tao, Cardiovascular Center, Children’s Hospital of Fudan University, China

    • Objectives To investigate the functions and microstructure changes of cerebrovascular endothelial cell(EC) after different CPB mode.

    Methods 24 S.D. rats(469.0±45.2g) were equally divided into four groups, which were underwent normothermic CPB for 120min(group A), DHLF for 60min(B), DHCA for 60min(C) and sham group(D) via right carotid and jugular cannulation. The internal jugular vein blood examples were taken before and after bypass to test plasma NO concentration. The middle cerebral artery(MCA) was harvested to evaluate the EC response induced by different concentration of acetylcholine. The eNOS protein expression was determined by Western-immunoblotting. The hippocampus was harvested to observe the ultramicrostructure of EC.

    Results All the rats were successfully established and weaned from bypass. CPB reduced the plasma NO concentration compared with sham group. Plasma NO levels were lower in group B&C compared with A (3.94±0.15mg/L&2.93±0.33mg/L vs 4.33±0.17mg/L, P=0.002). Acetylcholine induced a dose-dependent MCA vasodilation in sham group(24.26±1.90% increase in diameter) that was attenuated in all CPB groups (9.60±1.09%, 5.97±0.68%&5.72±0.67%, P<0.01). The hypothermic bypass correlated with significantly reduced eNOS expression compared with group A(P<0.01), whilst eNOS expression was even lower in group C compared with group B(P=0.002). The ultramicrostructure of EC and capillary observed by electron microscope found normal in group A&D, but the V-R space widened in group B and structural injury in EC and cerebral edema in group C.

    Conclusion CPB can induce the cerebrovascular EC injury, particularly in DHCA/DHLF bypass mode. The severity of the EC dysfunction maybe associated with the degree of brain damage after CPB.