[Brain cell apoptosis after cerebral hypoxia-ischemia in neonatal rat].

OBJECTIVE

To investigate action of apoptosis in mechanisms of neonatal hypoxia-ischemia (HIE).

METHODS

Using HE staining, electronmicroscope, and terminal deoxynuleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique, we observed the histological features, time course and density of apoptotic cells and compared the ipsilateral hemisphere after permanent ischemia 1, 4, 18, 24, 40, 72 h, 7 days after 3 h hypoxia with that of sham-group.

RESULTS

Neurons in the cortex, hippocampus, thalamus exhibited cells shrink, chromatin condensation, apoptosis bodys under microscope, as demonstrated by in situ labeling of DNA breaks. The peak for apoptosis was shown at 18 h in the cortex.

CONCLUSION

In the HIE, apoptosis appears earlier than necrosis, and both of the different cell death forms may exist induced dose relativity.