Dynamical Assay of S-100B Proteins in Serum and Cerebrospinal Fluid after Subarachnoid Hemorrhage in Rabbits

Objective To study the dynamical changes in S-100B proteins in the serum and cerebrospinal fruid (CSF) after the experimental subarachnoid hemorrhage(SAH) and its clinical significance in rabbits. Methods Fifteen male rabbits were equally and randomly divided into three groups, i.e. control group, mild SAH (0.4 ml/kg of autologous blood was injected into the cistern magna of rabbits) and severe SAH (1.0 ml/kg of autologous blood was injected in the cistern magna) group. The levels of S-100B protein in serum and CSF were measured by enzyme-linked immunosorbent assay (ELISA) before the SAH and 1, 2, 3, 5 and 7 days after the SAH. Another 15 male rabbits also were equally and randomly divided into the three groups as the above-mentioned ones. The apoptosis of neurons in the inferior temporal lobes of the rabbits in the later three groups was determined by TdT-mediated nick end labeling (TUNEL) 2 days after SAH. Results The CSF S-100B protein 1, 2 and 3 days after SAH were significantly higher in the mild SAH group than that in the control group (P0.01). The CSF levels of S-100B protein were significantly higher in the sever SAH group 1, 2 and 3 days after the SAH than those in both the control and mild SAH groups (P0.01). The CSF levels of S-100B protein 5 days after SAH was still significantly higher in the sever SAH group than that in the control groups (P0.01). There were insignificant difference in the serum levels among these three group (P0.05). The apoptosis rate of the neurons in the severe SAH group were significantly higher than that in the mild SAH group (P0.05), where the apoptosis rates of the neurons was significantly higher than that in the control group. Conclusion The CSF levels of S-100B protein early after the SAH may serve as an indicator of the severity of SAH.