1049

THE RELATIONSHIP BETWEEN THE EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE GENE EXPRESSION AND BRAIN CELLS APOPTOSIS 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 relationship between the gene expression of the inducible nitric oxide synthase (iNOS) and brain cells apoptosis following cerebral hypoxia-ischemia (HI) in the neonatal rats.

Methods: 7-day-old rat pups were subjected to a unilateral ligation of the common carotid artery following by a 2h 30 min hypoxic period (8%O2 in N2). Rapid competitive reverse transcriptase-PCR and in situ end labeling methods were used to detect the gene expression of iNOS and brain cells apoptosis separately in the hemisphere subjected to both ligation and hypoxia at different time points after HI.

Results: In the ipsilateral hemisphere following cerebral HI, the expression of iNOS mRNA began at 6h (0.412�� 0.127), peaked at 24h (2.020�� 0.241), and returned to baseline at 7 days. The evident increase of apoptotic cells in the ipsilateral hemisphere 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<0.01. The peak time of the overexpression of iNOS mRNA was coordinate with that of apoptosis following HI.

Conclusion: The increase in expression of iNOS mRNA and then the cell apoptosis could be induced by cerebral HI, The overexpression of iNOS could play a role in the induction of apoptosis following cerebral HI.