纳洛酮对脑局灶性缺血-再灌注大鼠血红素加氧酶-1表达的影响

The effect of naloxone on heme oxygenase-1 expression in focal cerebral ischemia-reperfusion in rats

目的探讨大鼠局灶性脑缺血再灌注后血红素加氧酶1(HO1)蛋白在缺血灶周围区的表达和纳洛酮干预后的影响。方法SD大鼠45只,随机分为三组:即假手术组、缺血再灌注组及纳洛酮组,每组15只。采用线栓法制作大鼠大脑中动脉闭塞(MCAO)局灶性脑缺血再灌注模型,在插入栓线及抽出线栓成功再灌注后,分别给予纳洛酮组大鼠腹腔注射纳洛酮3mg/kg(总量6mg/kg),假手术组及缺血再灌注组腹腔注射等量等渗盐水。以免疫组化法检测HO1的表达,原位末端脱氧核苷酸转移酶标记(TUNEL)法观察脑细胞凋亡细胞数。结果每个高倍视野下,缺血再灌注组HO1阳性细胞数与假手术组相比明显增多,平均为(51.6±10.8)个对(9.8±2.8)个,P<0.05;纳洛酮组与缺血再灌注组比较,缺血灶周围区HO1阳性细胞数平均为(63.5±10.0)个对(51.6±10.8)个,P<0.05。纳洛酮组TUNEL阳性细胞数显著低于缺血再灌注组[(20.5±3.5)个对(29.8±4.0)个],但高于假手术组[平均为(4.2±2.0)个],组间比较,差异有显著性(P<0.05)。结论纳洛酮可减少MCAO局灶性脑缺血再灌注导致的神经细胞凋亡,其机制可能与纳洛酮增加HO1的表达有关。

Objective To discuss the expression of heine oxygenase-1 （ HO-1 ） protein around ischemic focus after focal cerebral isehemia-reperfusion in rats and the effect after naloxone intervention. Methods Forty-five Sprague-Dawley rats were randomly allocated into three groups （ n = 15, each） ： sham operation group, ischemia-reperfusion group, and naloxone group. A focal cerebral isehemia-reperfusion model was built by the suture method for middle cerebral artery occlusion （MCAO） in rats. After the successful reperfusion by inserting and withdrawing sutures, naloxone （3 mg/kg） was injected intraperitoneally into the rats of naloxone group, and isotonic saline was injected intraperitoneally into the rats of sham operation group and ischemia-reperfusion group. The expression of HO-1 was assayed by immunohistochemistry. In situ terminal deoxynueleotidyl transferase （TUNEL） assay was used to observe the numbers of brain apoptosis. Results The numbers of HO-1 positive cell in the isehemia-reperfusion group were significantly higher than those in the sham operation group with an average of 51.6 ± 10. 8 vs 9. 8 ± 2.8/highpower field （HP） （ P 〈0. 05）. The numbers of HO-1 positive cell around the isehemie foei in the naloxone group were higher than those in the isehemia-reperfusion group averaged 63.5 ± 10. 0 vs 51.6 ± 10. 8/HP （ P 〈 0. 05 ）. The numbers of TUNEL positive cell in the naloxone group were significantly lower than those in the isehemia-reperfusion group （ 20. 5 ± 3.5 vs 29. 8 ± 4. 0/HP, ） , but were higher than those in the sham operation group （4. 2 ± 2. 0/HP） , and there were significant differences between the groups （P 〈 0.05）. Conclusion Naloxone may reduce neuronal apoptosis caused by focal cerebral isehemia-reperfusion injury after MCAO ,and its mechanism may be associated with the increase of naloxone-inclaecd HO-1 expression.