Objective To observe the expression changes of 3-nitrotyrosine (3-NT), inducible nitric oxide synthase (iNOS), and nitric oxide (NO) in brain tissues of ischemia-reperfusion rats treated with different doses of hydroxysafflor yellow A (HSYA) by intravenous injection.Methods The healthy adult male SD rats were randomly divided into the sham operation group, model group, low-dose HSYA group, medium-dose HSYA group and high-dose HSYA group.In the sham operation group, rats' common carotid artery, internal carotid artery and external carotid artery were exposed, and then sutured.The other rats were subjected to a 60-min middle cerebral artery occlusion and 24-h reperfusion (MCAO/R).The rats in the low-dose, medium-dose and high-dose HSYA groups were injected with 2.5, 5 and 10 mg/kg HSYA, respectively, in the tail vein at 60 min after ischemia, and the same volume of Tris buffer was injected into the tail vein of rats in sham operation group and model group.All rats were continued to raise for 24 h.The expression of 3-NT and iNOS in the rat brain tissues after ischemia-reperfusion in each group was examined by Western blotting.The NO level was also detected by Griess assay.Results The absolute gray values of 3-NT in the sham operation group, the model group, the low-dose HSYA group, the medium-dose HSYA group and the high-dose HSYA group after ischemia-reperfusion were (2.81±1.37)×103, (46.86±4.75)×103, (44.51±4.13)×103, (13.88±2.98)×103, and (6.38±2.66)×103, respectively;the absolute gray values of iNOS of each group were (2.25±0.32)×103, (79.67±4.73)×103, (75.29±4.08)×103, (27.31±2.77)×103, (19.19±1.86)×103, respectively.In the model group and low-dose, medium-dose, and high-dose HSYA groups, the levels of NO were (16.50±2.20), (15.40±1.44), (10.33±1.30), and (6.80±0.73) nmol/mg.The levels of 3-NT, iNOS and NO in brain tissues of the model group, low-dose HSYA group, medium-dose HSYA group and high-dose HSYA group were higher than those of the sham operation group (all P<0.05).The levels of 3-NT, iNOS and NO in the brain tissues of rats in the low-dose HSYA group were not significantly different from those in the model group (P>0.05).The levels of 3-NT, iNOS, NO in the medium-dose and high-dose HSYA groups were lower than those in the model group and low-dose HSYA group (all P<0.05), and the levels of 3-NT, iNOS and NO in brain tissues of high-dose HSYA group were lower than those in medium-dose HSYA group (all P<0.05).Conclusion HSYA can inhibit the expression of 3-NT, iNOS, and NO in rat brain tissues after ischemia-reperfusion.The higher the HSYA dose is, the more obvious the effect will be.

Peroxisome proliferators-activated receptor γ (PPARγ) belongs to a nuclear receptor superfamily. Many studies have shown that PPARγ can help to improve the outcome of cerebrovascular disease. PPARγ can reduce inflammatory response, oxidative stress as wel as enhance the hematoma removal abilities of microglia and macrophages, and it plays an important protective role in intracerebral hemorrhage.

目的 探讨前循环同侧短暂性脑缺血发作(TIA)对后续脑梗死的影响及可能机制.方法 选取113例前循环脑梗死患者,分为单纯脑梗死组87例和进展脑梗死组26例,分别比较2组早期神经功能恶化(END)、美国国立卫生研究院卒中量表(NIHSS)评分、3个月改良Rankin量表(mRS)评分、脑梗死体积、高敏C反应蛋白(hs-CRP)及其他相关危险因素.结果 与单纯脑梗死组比较,进展脑梗死组发生END比例1j(11.5％ vs 31.0％)、出院NIHSS评分[(1.85±2.31)分vs (3.30±3.65)分]、3个月mRS评分[(0.90±0.83)分 vs(1.78±1.77)分、hs-CRP[(2.52±3.23)mg/L vs (6.21±32.23)mg/L]、脑梗死体积[(3.92±8.05)cm3 vs(9.15±15.07)cm3均明显减小(P＜0.05);脑梗死前7～14 d TIA发生2～3次、TIA持续时间＞10 min的患者上述指标的变化最为显著;hs-CRP与END(r=0.311,P=0.014)、入院NIHSS评分(r=0.455,P=0.000)及脑梗死体积呈正相关(r=0.524,P=0.000).结论 TIA对后续脑梗死具有缺血预处理作用,其作用可能与hs-CRP水平下降有关.

Objective To examine the expression and activity of 12/15-lipoxygenase(12/15-LOX) in rats exposed to cerebral ischemia-reperfusion (I/R), and investigate the regulatory effect of 12/15-LOX on peroxisome proliferator-activated receptors γ (PPARγ）. Methods Adult male Sprague-Dawley rats underwent 60 min middle cerebral artery occlusion followed by a 24-hour reperfusion (MCAO/R) and were treated with either vehicle (I/R group) or 15-hydroxyeicosatetraenoic (15-HETE) group 30 min before operation. According to digital table method, rats were randomly separated into every group. There were 12 rats of Sham-operated group and 15-HETE group，18 rats of I/R group. After 60 min ischemia and 24 h reperfusion, immunoflorescene staining and western blot were used to evaluate the expression of 12/15-LOX and PPARγ in ischemia cortex. The content of 15-HETE was evaluated by enzyme immunoassay. Results (1)Western blot showed that the expression of 12/15-LOX whole protein was enhanced in I/R group compared with sham-operated group (I/R group:0.688±0.063 vs sham-operated group:0.458±0.026，t=-8.195，P<0.05). Immunoflorescence staining revealed that the localization of 12/15-LOX was consistent with PPARγ in ischemia brain. Enzyme immunoassay found the content of 15-HETE in I/R group was dramatically increased compared with sham-operated group (I/R group: (59.402±4.579) ng/mg vs sham-operated group:(31.202±2.188) ng/mg，t=-12.787, P<0.05). (2) 15-HETE (12/15-LOX metabolite) treatment dramatically increased I/R-induced expression of PPARγ total protein(I/R group:1.584±0.116，15-HETE-group:3.826±0.198，t=-23.884，P<0.05) and nuclear translocation (I/R group:12.167±1.131，15-HETE-group: 25.726±1.843，t=-15.360，P<0.05), and suppressed PPARγ cytoplasmic retention (that means the enhancement of PPARγ activity, I/R group: 2.394±0.373，15-HETE-group:1.184±0.342，t=5.860，P<0.05), compared with I/R group. Conclusion The increased expression of 12/15-LOX during cerebral I/R injury can regulate the expression and activity of PPARγ through its metabolite. Key words: Brain ischemia; Reperfusion injury; Arachidonate 12-lipoxygenase; Arachidonate 15-lipoxygenase; Hydroxyeicosatetraenoic acids; PPAR gamma

Objective To examine peroxisome proliferator-activated receptor(PPAR)isotypes (PPARα,PPARδ/βand PPARγ)expression in rats after cerebral ischemia-reperfusion(I/R)and I/R in combination with pan-PPAR co-agonist,and to explore the effect of altered PPAR expressions in brain injury.Methods Adult male SD rats underwent 2-hour middle cerebral artery occlusion followed by a 22-hour reperfusion(MCAO/R).One hour before the operation,the mice received either vehicle(I/R-group)or bezafibrate(6 mg/kg)treatment(Beza-group).TTC(2,3,5-triphenyhetrazolium)staining was adopted to determine the volume of cerebral infarction.The expressions of PPAR isotypes were characterized by immunohistochemical staining(IHC)and Western blot.Furthermore,the spatial localizations of PPAR isotypes were analyzed with respect to ipsilateral ischemic(core and penumbra)and contralateral nonischemic hemisphere.Results Compared with sham-group,2 h ischemia and 22 h reperfusion caused(1) 44.30%infarct volume in average in ipsilateral hemisphere;(2)Marked increased PPAR expression in all three isotypes evaluated by IHC(t=8.63,9.29,13.62,P:0.000)and Western blot(PPARot by 1.47-fold,PPARδ/β by 3.52-fold,and PPARγ by 2.25-fold;t=8.16,9.24,6.43;P=0.000);(3)Marked increagc in PPAR staining in the ischemia-affected region of the ipsilateral MCA territory,in particular in the ischemic itmnumbra.No detectable increase in number and intensity was observed in the contralateral(nonischemic)hemisphere.The pan-PPAR co-agonists bezafibrate can activate all 3 subtypes of the receptor.Compared with I/R-group,(1)Ischemic size in bezafibrate-group rats was significantly decreased than that in I/R group(20.22±6.18 versus 44.30±4.54,t=7.69,P=0.000).(2)Bezafibrate treatment further increased the alterations of all PPAR expression,which were induced by the exposure of I/R,as determined by IHC(t=7.36,5.64,10.50,and P=0.000)and Western blot(PPARα by 95.45%,PPARS/β by 183.47%,and PPARγ by 224.61%;t=13.02,17.52,13.64,and P=0.000).(3)The PPAR immunoreactive expressions were observed in not only the ipsilateral but the contralateral hemisphere of bezafibrate-group.Conclusions Cerebral I/R injury increases the expression of all three PPAR isotypes and activation of PPAR by pan-PPAR agonist not only reduces ischemic size but further enhances the alteration of PPAR The up-regulation of PPAR expression may represent the compensatory self-protection against brain I/R injury.