The effect of circulatory arrest and retrograde cerebral perfusion on microtubule-associated protein 2: An immunohistochemical study in pig hippocampus

Microtubule-associated protein 2 (MAP2) immunohistochemical labeling in the hippocampus was studied to assess the protective effect of brain perfusion during surgery requiring hypothermic circulatory arrest in 24 pigs exposed to anesthesia alone (control), 120 min of complete circulatory arrest at 15°C, 120 min of retrograde cerebral perfusion at 15°C, or 120 min of anterograde cerebral perfusion at 15°C. Pigs were reperfused for 60 min and sacrificed. In the control and anterograde perfusion groups, the intensity of MAP2 labeling was similar in all regions of the hippocampus. Circulatory arrest and retrograde perfusion resulted in significant reduction of MAP2 labeling (28% and 38% respectively of control, P < 0.001) of neurons in the CA1 region. MAP2 labeling may be useful for assessing early damage in the hippocampus in this model.