Effects of Activated ACM on Expression of Signal Transducers in Cerebral Cortical Neurons of Rats

To explore the roles of astrocytes in the epileptogenesis, astrocytes and neurons were isolated, purified and cultured in vitro from cerebral cortex of rats. The astrocytes were activated by ciliary neurotrophic factor (CNTF) and astrocytic conditioned medium (ACM) was collected to treat neurons for 4, 8 and 12 h. By using Western blot, the expression of calmodulin dependent protein kinase Ⅱ (CaMKⅡ), inducible nitric oxide synthase (iNOS) and adenylate cyclase (AC) was de- tected in neurons. The results showed that the expression of CaMKⅡ, iNOS and AC was increased significantly in the neurons treated with ACM from 4 h to 12 h (P<0.05), and that of iNOS and AC peaked at 8 h and 12 h respectively. It was suggested that there might be some epileptogenic factors in the ACM and such signal pathways as NOS-NO-cGMP, Ca2+?CaM-CaMKⅡ and AC-cAMP-PKA might take part in the signal transduction of epileptogenesis.

不同尿素氮水平尿毒血清对人脐静脉内皮细胞的影响

目的:观察不同BUN水平尿毒血清对体外培养人脐静脉内皮细胞(HUVEC)的影响,并探讨尿毒症患者动脉粥样硬化发病的可能机制。方法:比色法测定HUVEC上清液NO、MDA的水平;免疫细胞化学法测定胞浆iNOS表达;酶联免疫吸附法(ELISA)测定上清液iNOS蛋白水平。结果:尿毒血清各组均可上调HUVEC的MDA生成,且以BUN≥50mmol/L的尿毒血清组对MDA上调最明显(P<0.01);尿毒血清各组可下调HUVEC的NO生成,呈BUN浓度依赖性关系(P<0.01);尿毒血清各组可激活HUVEC的iNOS,诱导细胞生成大量NO,但随着BUN水平的升高,NO、iNOS呈下降趋势,BUN≥50mmol/L尿毒血清组下降显著(P<0.01)。结论:尿毒血清对HUVEC有毒性作用,呈BUN浓度依赖性关系,尤其是BUN≥50mmol/L时,细胞损伤更为加重。