17β雌二醇对氯胺酮诱导发育期大鼠皮质神经细胞凋亡的影响

Effects of 17β-estradiol on ketamine-induced neuroapoptosis in the developing rat brain

目的探讨17β雌二醇对氯胺酮诱导发育期大鼠额叶皮质区神经细胞凋亡的影响以及机制。方法30只7日龄雄性SD幼鼠,随机分为对照组(C组)、氯胺酮组(K组)、氯胺酮+17β雌二醇组(K+E组),每组10只。C组连续3 d腹腔注射等容量生理盐水;K组连续3 d腹腔注射75 mg/kg氯胺酮;K+E组连续3 d腹腔注射75mg/kg氯胺酮同时皮下注射600μg/kg 17β雌二醇。末次注药后24 h,取额叶皮质应用TUNEL法检测神经细胞凋亡,同时应用Western-blot法检测bcl-2,Bax以及cleaved-caspase-3蛋白的水平。结果与对照组比较,氯胺酮组皮质区凋亡细胞显著性增加(P<0.01),Bcl-2蛋白水平显著性下降(P<0.01),Bax蛋白水平显著性增加(P<0.01),Bcl-2/Bax显著性降低(P<0.01),cleaved-caspase-3蛋白水平显著性增加(P<0.01)。与氯胺酮组比较,氯胺酮+17β雌二醇组皮质区凋亡细胞显著性下降(P<0.01),Bcl-2蛋白水平显著性增加(P<0.01),Bax蛋白水平显著下降(P<0.01),Bcl-2/Bax显著性增加(P<0.01),cleaved-caspase-3蛋白水平显著性下降(P<0.01)。结论 17β雌二醇可对氯胺酮诱导的发育期大鼠大脑皮质区神经细胞凋亡产生保护作用,其机制可能与影响bc1-2和Bax蛋白表达有关。

Objective To investigate the effect of 17β-estradiol on ketamine-induced neuroapoptosis in neonatal rats. Methods 30 aged 7 days SD male rats were randomly divided into group C、K、K ＋ E,10 per group. Group C was intraperitoneally injected with same volume of saline for three consecutive days,group K was intraperitoneally injected with 75 mg / kg ketamine for three consecutive days,group K ＋ E was intraperitoneally injected with 75 mg / kg ketamine in combination with 600 μg / kg 17β-estradiol injected subcutaneously for three consecutive days. 24 hours after the last injection,five rats from each group were decapitated under deep anesthesia and the PFC portion was isolated to detect neuroapoptosis by TUNEL assay. The PFC of other rats was harvested to determine bcl-2,Bax and cleaved-caspase-3 by Western-blot. Results Compared with the group C,neuroapoptosis increased significantly after being treated with 75 mg / kg ketamine for three consecutive days（ P 〈0. 01）,while bcl-2 level reduced（ P 〈0. 01）,Bax and cleaved caspase-3 level increased greatly（ P 〈0. 01）,and bcl-2 / Bax reduced greatly（ P 〈0. 01）. Compared with the group K,neuroapoptosis reduced significantly in group K ＋ E（ P 〈0. 01）,while bcl-2 level increased（ P 〈0. 01）,Bax and cleaved caspase-3 level reduced greatly（ P〈 0. 01）,and bcl-2 / Bax increased greatly（ P 〈0. 01）. Conclusion 17β-estradiol can protect against ketamine-induced injury in the developing brain by regulating the expressions of bcl-2 and Bax.