nNOS expression of hippocampal neurons in aged rats after brain ischemia/reperfusion and its role in DND development.
OBJECTIVE
To study the role of neuronal nitric oxide synthase (nNOS) in aged rats' hippocampal delayed neuronal death (DND) following brain ischemia.


METHODS
Models of incomplete brain ischemia were induced by clipping common carotid artery. A total of 46 aged SD rats were divided into 8 groups: normal control group (Group A, n=5), sham-operation group (Group B, n=5), reperfusion 1, 6, 12, 24, 48, and 96 hours groups after brain ischemia for 30 minutes (Group C, D, E, F, G, and H, n=6/group). The expression of nNOS was examined by immunohistochemistry and neuronal ultrastructural changes were observed by the transmission electron microscopy (TEM) at different time points after reperfusion.


RESULTS
Immunohistochemistry showed that nNOS expression in the hippocampal neurons was high in Group E, low expression in Group D, moderate expression in Group F and G. There was nearly no expression of nNOS in Group A, B, C, and H. Ultrastructure of hippocampal neurons was damaged more severely in reperfusion over 24 hours groups.


CONCLUSIONS
Nitric oxide (NO) may be one of the important factors in inducing DND after ischemia/reperfusion.
Yang
Chuanhong
C
Department of Medical Research, General Hospital of Guangzhou Military Command, China. baihongchen@263.net
Lai
Huangwen
H
Zhan
Chunlie
C
Xiao
Yuhua
Y
Zheng
Wenling
W
D000818:Animals; D017209:Apoptosis; D002545:Brain Ischemia / Q000201:enzymology*; D005260:Female; D006624:Hippocampus / Q000201:enzymology* / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology*
D019001:Nitric Oxide Synthase