大鼠脑组织γ刀照射后水通道蛋白4mRNA与蛋白激酶C活性变化的相关性研究  

Correlation between AQP4 mRNA and PKC activity after gamma knife radiosurgery in rat brain

作　　者：沈光建[1] 唐文渊[2] 许民辉[1] 耿明英[1] 孙善全[3] 

机构地区：[1]第三军医大学大坪医院野战外科研究所神经外科,重庆400042 [2]重庆医科大学第一附属医院神经外科 [3]重庆医科大学第一附属医院基础部解剖教研室

出　　处：《中华放射医学与防护杂志》2009年第5期479-482,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的探讨大鼠脑组织γ刀照射后水通道蛋白（AQP）4mRNA的表达变化及其与蛋白激酶（PKC）活性变化的相关性。方法Wistar大鼠30只，用γ刀照射尾状核头部（单靶点照射，中心剂量100Gy，准直器为4mm）制成放射外科模型，观察照射后1、3、7、15、30和45d脑组织中AQP4mRNA、PKC活性及细胞内游离Ca^2＋的变化和相互关系。检测方法分别为RT-PCR、液态闪烁计数以及Fura-2／AM法。结果AQP4mRNA的表达由正常对照的0．99±0．05逐渐增加至照射后30d的2．32±0．10，45d下降至2．21±0．08；PKC活性及脑细胞内游离Ca^2＋浓度则分别由正常对照的0．5896±0．2101和455．82±20．13逐渐下降至30d的0．0404±0．0294和196．72±9．87，45d又回升至0．1050±0．0607和219．26±10．43。除1d外，AQP4 mRNA、PKC活性及细胞内游离a^2＋均与对照组差异有统计学意义（P〈0．01）。AQP4 mRNA与PKC呈显著负相关（r=-0．918，P=0.003），脑细胞内游离Ca^2＋浓度与PKC活性呈显著正相关（r=0．959，P=0．001）。结论7刀照射后PKC活性受抑可能是脑组织AQP4mRNA表达上调的因素之一，而PKC活性降低则可能与高剂量电离辐射致细胞内Ca^2＋浓度降低有关。Objective To explore the change of AQP4 mRNA expression and the correlation with PKC in rat brain irradiated by γ knife radiosurgery （GKS）. Methods 30 Wistar rats were used in the study. The experimental radiosurgery model was established by radiating rat left rotral eaudate nucleus with GKS（one target, 100 Gy in isocenter dose and 4 mm in collimator）, and was examined at 1,3,7,15,30 and 45 d post-irradiation. AQP4 mRNA expression, PKC activity and free intracellular calcium ion concentration （ [ Ca^2＋ ] i ） of brain tissue were determined by RT-PCR, liquid scintillation counter and Fura-2/AM, respectively. Results AQP4 mRNA expression increased gradually from 0.99 ± 0.05 in control group to 2.32 ± 0.10 at 30 d post-irradiation, and decreased to 2.21 ± 0.08 at 45 d post-irradiation. The PKC activity and the free [Ca^2＋ ]i decreased gradually from 0.5896 ± 0.2101 and 455.82 ± 20.13 in control group to 0.0404 ＋ 0.0294 and 196.72 ＋ 9.87 at 30 d postirradiation, and increased to 0. 1050 ± 0.0607 and 219.26± 10.43 at 45 d post-irradiation, respectively. The significant differences were found between experimental group and control group except at 1 d post-irradiation （P〈0.01）. The correlation between AQP4 mRNA and the PKC activity was negative （P = 0.003, r = -0.918）, while that between the free [Ca^2＋ ]i and the PKC activity was positive（ P = 0.001, r = 0.959）. Conclusions The increased expression of AQP4 mRNA might result from the inhibition of PKC activity due to the reduction of free [ Ca^2＋ ] i after GKS.

关 键 词：大鼠 Γ刀 水通道蛋白4 蛋白激酶C 钙离子 

分 类 号：R285.5[医药卫生—中药学]