The Response Of The Cerebral Glial Cell And Cortical Neuron To The Different Temperature Cardiopulmonay Bypass At Different Time Point In Rabbits

Objective To investigate the response of the cerebral glial cell and neuron of rabbits to the different temperature cardiopulmonary bypass at different time point.Methods Thirty New Zealand white rabbits were randomly allocated into three groups: normothermia CPB 36℃～37℃(group A), mild hypothermia CPB 32℃～34℃(group B), hypothermia CPB 26℃～28℃(group C); made the open-heart CPB model, maintaining hematocrit 20%～25%, The measurement spots of brain temperature lied at tympanum, S100B and NSE were measured by instantly before CPB ( T₁), 1 hour after CPB(T₂), and 2 hour after CPB (T₃). The duration of CPB was 2 hours; Stimulating from ischiadic nerve at the time point of T₁, T₂, T₃ to induce SCEP, recording the latency and the amplitude of SCEP. The cortex was sliced for electro microscopic examination.Results The reveal level of S100B had no difference among the three groups, at the same time point, compared in interclass(P>0.05),but there was significant difference inner the group(P<0.05). There was difference of the reveal level of NSE among the three groups, and inner the group (P<0.05). The latency of SCEP in group C was longer than that in group B, the latency of SCEP in group B was longer than that in group A, compared between each group, the difference is significant (P<0.05). The Amplitude of SCEP in group C was lowest, compared between each group , the difference is significant (P<0.05). The super microstructure of neuron and fiber after CPB had no significant difference among the three groups: the nucleus and the cytoplast of the neuron in cortex were swollen, and the heterochromatin of chromatin in nucleus was agglomerated, the perinuclear space was enlarged slightly, the electron density of the nuclear matrix was degraded.Conclusion The neuron and the glial cells of rabbits were damaged and the latency and amplitude of SCEP were inhibited during CPB, the longer the CPB duration time, the more serious the damage and the inhibition.