Objective: To investigate the relationship between inflammatory response and cell apoptosis in the perihematoma region in patients with intracerebral hemorrhage (ICH).
Methods: Surgical specimens were obtained from the area 1 cm adjacent to the hematoma. Thirty patients with ICH were divided into five groups: 6, 7, 5, 6, 6 patients in surgery<6 hours, 6-12 hours, 12-24 hours, 24-72 hours and >72 hours groups after the onset, respectively. The control group specimens were obtained from the brain tissues distant to the hematoma in the process of craniotomy in the patients of two former groups. Sections were stained with hematoxylin and eosin (HE) for the examination of pathological changes. Immunohistochemistry, terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL) and reverse transcription-polymerase chain reaction (RT-PCR) were applied to determine apoptosis cells, Bax and Bcl-x protein and mRNA.
Results: The tissues from perihematoma region were almost normal in control group and <6 hours group. They were slightly damaged in 6-12 hours group, became worse in 12-24 hours group and most severe in 24-48 hours group, and they became better latter and were similar to the control group on 8th day. Infiltration of neutrophils, macrophages and lymphocyte appeared gradually at 6-12 hours, and became much more prominent at 12-24 hours (all P<0.01). The reactive gliosis began to appear at 24-72 hours, and enhanced after 72 hours (all P<0.01). The expression of the apoptosis and Bax protein increased gradually after 6 hours, reaching the peak at 12-24 hours (P<0.05 or P<0.01), and decreased gradually later. The changes in the levels of Bax mRNA were similar to that of the result of immunohistochemistry. Although the expression of Bcl-x protein and mRNA seemed to be increased at 12-72 hours, there was no significant difference between groups (P>0.05). The correlation analysis showed that the infiltration of neutrophils, macrophages and lymphocyte was positively correlated to the TUNEL positive cells and expression of Bax protein and mRNA (P<0.05 or P<0.01), and showed no correlation to Bcl-x protein and mRNA (all >0.05).
Conclusion: There is a close relationship between inflammatory response and apoptosis and tissue damage in the perihematoma area in ICH.