Abstract: ObjectiveTo study possible mechanism through investigating the pathological and ultrastructural characters of secondary injury to perihematoma in intracerebral haemorrhage (ICH) rats.MethodsSprague Dawley male rats were subjected to ICH models. They were randomly divided into test group and control group. The rats in the test group were divided into 7 subgroups at 1h,3h,12h,24h,48h,72h and 7d after ICH; while those in control group were divided into 3 subgroups at 3h,24h,72h after saline injection. Each subgroup contained 5 rats. 2 rats from each group were stained by 2% triphenyltetrazolium chloride(TTC) to observe the pathological change.3 rats were picked up from each group to do optical microscope and electric microscope investigation on perihematoma tissue and ipsilateral cortex.ResultsHematoma tissue was demonstrated as black brown by TTC staining, no white infarcted area was detected around hematoma. In addition, there was a transitional zone between hematoma and normal tissue under microscopy; the involved tissue looked loose with varied edematous cells. Astrocytes appeared swollen and neural cells looked degenerated and necrosis. Meanwhile, capillary hyperplasia around hematoma with foot plate swollen were detected, no remarkable neural cells change was observed. 24 h after blood injection, astrocytes started to swell, part of them became degenerated and necrosis. Neural cells appeared mild degenerated and blood brain barrier were destroyed. 72 h after ICH, astrocytes showed highly swollen with neural cells degenerated.ConclusionSecondary injury to perihematoma has been identified and the pathological and ultrastructural changes have been observed.

Key words: intracerebral haemorrhage, cerebral edema, electric microscope, pathology, rat