摘要
目的观察垂体腺苷酸环化酶激活肽(PACAP)对局灶性脑缺血-再灌注大鼠的脑保护作用及对核因子κBp65(NF-κBp65)和肿瘤坏死因子α(TNF-α)表达的影响。方法取健康雄性SD大鼠72只,采用随机数字法分为假手术组、缺血-再灌注组、PACAP组,每组大鼠24只,每组再分为再灌注12h和24h组,每时间点12只大鼠。采用线栓法建立大脑中动脉缺血模型,于缺血后2h进行再灌注。PACAP组于再灌注30min内,由尾静脉注射(5×10-7)%的PACAP,(5×10-9)g/kg,假手术组和缺血-再灌注组,用等体积(0.1ml/kg)的等渗盐水代替PACAP。再灌注12、24h取脑,光镜下观察脑组织的结构;并采用Western印迹法检测NF-κBp65的表达,免疫组化法检测TNF-α的表达。结果①PACAP组大鼠光镜下脑组织细胞损伤程度与缺血-再灌注组相比明显减轻。②PACAP组再灌注12、24h,TNF-α阳性细胞的表达分别为(20.0±2.5)、(30.7±1.3)个/高倍视野,缺血-再灌注组分别为(40.8±3.7)、(60.7±3.5)个/高倍视野,与假手术组的(2.8±0.8)、(3.0±0.7)个/高倍视野的表达比较,差异均有统计学意义(P<0.01),缺血-再灌注组与PACAP组比较,差异亦有统计学意义(P<0.01)。③再灌注12和24h,PACAP组NF-κBp65表达的灰度值为57±7、49±8,缺血-再灌注组为90±14、74±10,与假手术组的41±17、41±10比较,差异均有统计学意义(P<0.01),缺血-再灌注组与PACAP组比较差异亦有统计学意义(P<0.01)。结论PACAP能抑制大鼠局灶性脑缺血-再灌注后TNF-α、NF-κBp65的表达,这可能是其脑保护作用机制之一。
Objective To observe the effects of pituitary adenylate cyclase activating polypeptide （PACAP） on neuroprotection and expressions of nuclear factor kappa B （NF-KB） p65 and tumor necrosis factor-α （TNF-α） after focal cerebral ischemia-reperfusion in rats. Methods Seventy-two healthy male Sprague-Dawley rats were randomly divided into sham-operation, ischemia-reperfusion, and PACAP groups （n = 24 in each group）. Each group was redivided into reperfusion 12- and 2g-hour groups（n = 12 at each time point）. A model of middle cerebral artery occlusion was induced by the intraluminal suture method, and reperfusion was performed two hours after ischemia. 5 × 10^-7% PACAP（5 × 10^-9 g/kg） was injected via the tail vein within 30 min reperfusion in the PACAP group. PACAP was replaced by the same volume （0. 1 ml/kg） of isotonic saline in the sham-operation group and ischemia-reperfusion group. Their brains were harvested after 12- and 2g-hour reperfusion, and histological observation of the brain tissue were performed. The expression of NF-kB p65 was detected by Western blot, and the expression of TNF-α was detected by immunohistochemical method. Results As compared with the ischemia-reperfusion group, the degeneration degree of cell injury improved significantly in rat brain samples under the light microscope in the PACAP group. As compared with 2.8 ± 0. 8 and 3.0 ± 0. 7/highpower field in the sham-operation group, the expressions of NF-KB at 12 and 24 hours after reperfusion were 20. 0 ± 2. 5 and 30. 7 ± 1.3/ highpower field in the PACAP group, and 40.8 ±3.7 and 60.7 ±3.5/highpower field in the ischemiareperfusion group, and there were significant differences among them（P 〈0. 01 ）. There were also statisti- cal differences between the PACAP group and the ischemia-reperfusion group（ P 〈 0. 01 ）. The gray values of the expression of NF-KB p65 were 57 ±7 and 49 ± 8 in the PACAP group at 12 and 24 hours after reperfusion, and they were 90 ± 14 and 74 ± 10 in the ischemia-reperfusion group. As compared with 41 ± 17 and 41 ± 10 in the sham-operation group, there were significant differences（ P 〈 0. 01 ）. There were also significant differences between the ischemia-reperfusion group and the PACAP group（P 〈0.01）. Conclusion PACAP can inhibit the expressions of TNF-α and NF-KB during focal cerebral ischemia-reperfusion in rats. This may be one of the mechanisms of its neuroprotective effect.
出处
《中国脑血管病杂志》
CAS
2008年第8期364-368,共5页
Chinese Journal of Cerebrovascular Diseases
关键词
脑缺血
再灌注损伤
垂体腺苷酸环化酶激活肽
NF—kB
肿瘤坏死因子Α
Brain ischemia
Reperfusion injury
Pituitary adenylate cyclase activating polypeptide
Nuclear factor-kappa B
Tumor necrosis factor-α
