1048

TYPE III CELL DEATH IN NEONATAL RATS FOLLOWING CEREBRAL HYPOXIA-ISCHEMIA

Zhou W1, Wu S-M2, Chen H-J2

1 Guangzhou Children’s Hospital, Guangzhou, China

2 Shanghai Institute for Pediatric Research, Shanghai, China

 

Objective: To investigate the forms of delayed neuronal death following cerebral hypoxia-ischemia(HI) in neonatal rats.

Methods: Using HE staining and In situ end labeling (ISEL), the authors observed the histological features of cells death in the cerebral cortex and hippocampus at ipsilateral hemisphere in neonatal rat models of HI.

Results: As a special type of cell death, the type III cell death was observed in the study during investigating cell death following HI in neonatal rat brains. Under light microscope, the nuclear chromatin of type III cells condensed, the cell volume shranked, showing characteristics of type I (apoptotic) cells, in the meantime, those cells were rich in cytoplasm, and the integrity of the plasma membrane was lost, showing characteristics of type II (necrotic) cells. Type III cells had no perinuclear halo and apoptotic bodies examined by ISEL. The evident increase of type I cells in the ipsilateral hemisphere of group HI began at 6h following HI (21.3±3.5/10hpf), peaked at 24h (63.7±3.2/10hpf), which was higher than that of the control (7.3±2.3/10hpf), p<0.001. There was no type III cells in the normal brain tissue, while the type III cells were observed in the ipsilateral hemisphere at 24h following HI (50.6±6.3/10hpf),and the type III cells peaked at 48h (75.6±10.2/10hpf), which was higher than the type I cells (42.3±4.5/10hpf) at the same timepoint, p<0.01.Type III cells were mainly located in the necrotic or perinecrotic areas.

Conclusions: Type III cell death was mainly involved in the delayed cell death following hypoxic-ischemic injury except for the existence of necrosis and apoptosis. Type III cell death was a special type of cell death, which related to apoptosis and necrosis.