Abstract:

Abstract：Objective To observe apoptotic cells and caspase-3-positive cells in ipsilateral neonatal hypoxic-isch⁃
emia encephalopathy (NHIE) model in mice. Methods CD1 mice of age 7 days (n=30) were randomly divided into two
groups: sham group (n=9) and model group (n=21). NHIE model was induced by right common carotid artery ligation fol⁃
lowed by 8% oxygen hypoxia for 100 min. TTC staining was used to determine area of brain infarction. DAPI staining was
used to detect pathological change in brains. TUNEL assay was used to detect apoptotic cells and fluorescence immunohisto⁃
chemistry was used to detect caspase-3 expression in the ipsilateral brain. Results No infarct was detected in sham group.
Cells were densely and orderly arranged in brain. TUNEL-positive cells (18.57±4.98) and caspase-3-positive cells (9.17±
2.14) in the ipsilateral brain were both less than those in the ipsilateral brain of mice in model group (209.57±41.27) and
(63.33±16.22) respectively. Mice in model group presented infarct in the right hemisphere with more dead cells and wider in⁃
terstitial space compared with sham group. Conclusion Brain injury in NHIE model might be related to the increasing cas⁃
pase-3 expression thus leads to apoptosis.

Key words: hypoxia-ischemia, cerebral infarction, apoptosis, caspase 3, mice, hypoxic-ischemic encephalopathy