[Changes in DNA repair enzymes in rat ventroposterior nucleus of the thalamus after cerebral cortex infarction].
OBJECTIVE
To investigate the damage within the ventroposterior nucleus (VPN) of the thalamus after focal cortical infarction and its mechanism, and explore the effect of ebselen on the oxidative damage after cerebral cortex infarction in hypertensive rats.


METHODS
Middle cerebral artery occlusion (MCAO) was induced in stroke-prone renovascular hypertensive rats (RHRSP), and the rats were divided into four groups by table of random number: sham operation group, model group, vehicle group and ebselen group, each group consisted of 8 rats. In animals subjected to sham surgery the middle cerebral artery was exposed only. Ebselen (5 ml/kg) or vehicle (a mixed solvent consisting of 0.5% carboxymethyl cellulose and 0.02% Tween 20, 5 ml/kg) was given by gastric gavage starting 24 hours after cerebral cortical infarction. Two weeks after the MCAO, the rats were sacrificed, and VPN from each group was sectioned and stained with hematoxylin-eosin (HE), and apurinic/apyrimidinic endonuclease (APE) and Escherichia coli MutY DNA glycosylase (MYH) were determined by immunohistochemistry.


RESULTS
HE staining showed that ebselen ameliorated the VPN damage induced by ischemia. Immunohistochemical imaging analysis revealed a distinct nuclear staining of APE and nuclear and cytoplasm distribution of MYH in the entire region of the VPN. Compared with sham operation group, the number of APE and MYH positive cells decreased in model group and vehicle group (APE: 57.0±14.7, 49.4±12.5 vs. 101.0±13.6, MYH: 15.0±4.7, 10.4±2.5 vs. 56.0±13.2, all P<0.05). Compared with model group and vehicle group, the number of APE and MYH positive cells increased significantly in ebselen group (APE: 72.2±7.6 vs. 57.0±14.7, 49.4±12.5, MYH: 32.2±7.6 vs. 15.0±4.7, 10.4±2.5, all P<0.05); the difference of the number of APE and MYH positive cells between model group and vehicle group showed no statistical significance.


CONCLUSIONS
After 2 weeks of MCAO, there is a marked decrease of APE and MYH in VPN; ebselen can obviously increase the level of APE and MYH, and ebselen may protect the VPN of the thalamus from damage after focal cortical infarction in rats.
Department of Pharmacology, Institute of Medical Sciences, Zhengzhou University, Henan Institute of Medical Sciences, Zhengzhou 450052, Henan, China.
Mei-Xia
MX
He
Jin-Sheng
JS
Zeng
Hai-Ying
HY
Hua
Shi-Hui
SH
Xing
Yun-Peng
YP
Ba
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D002544:Cerebral Infarction / Q000378:metabolism* / Q000473:pathology; D045643:DNA Repair Enzymes / Q000378:metabolism*; D006973:Hypertension; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013788:Thalamus / Q000378:metabolism*
D045643:DNA Repair Enzymes