Effect of ropivacaine-induced toxicity on learning and memory abilities and synaptophysin expression in immature mice / 中华神经医学杂志

Objective To study the effect of ropivacaine-induced toxicity on learning and memory abilities and synaptophysin expression of the hippocampus in immature mice. Methods Sixty 21-d-old SD mice were randomly divided into ropivacaine inducement group (R,n=30) and sodium chloride treatment group (N,n=30).Mice in each group were subdivided into 4 subgroups according to the different injection times (24 h,and 3,7 and 60 d after convulsion or injection,n=5); the protein expression of synaptophysin in the hippocampus at each time point were detected by Western blotting.The left 10 mice in each group were performed Mirror water maze test to explore the latency in finding the platform. Results The latency in finding the platform in mice of group R was gradually shortened as time being prolonged,and significant difference was noted between each 2 time points (P＜0.05); while no significant difference was noted between each 2 time points in mice of group N (P＞0.05).The latency in finding the platform in mice of group R was obviously longer as compared with that in group N at 24 h and 3 d time point (P＜0.05),but there were no significant differences at other time points (P＞0.05).The synaptophysin expression in the hippocampus of mice in group R was significantly lower as compared with that in group N at 24 h time point (P＜0.05). Conclusion The effect of single ropivacaine toxicity on learning and memory impairment of immature mice is transitional,which might be correlated to the synaptophysin expression in the hippocampus.

Identification and expression of shRNA vectors targeting human AMPKα2 / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct pGPU6/GFP/Neo-shRNA expression vector targeting human AMPKα2 gene and evaluate its silencing effect in SH-SY5Y cell line.</p><p><b>METHODS</b>The oligonucleotides designed by Ambion online CAD software targeting AMPKα2 were cloned into the pGPU6/GFP/Neo vector. After confirmation by DNA sequencing and enzyme digestion analysis, the recombinant vectors were transfected into the SH-SY5Y cell line via lipofectamine and the positive clones were selected using G418. The expression levels of AMPKα2 mRNA and protein in the transfected cells were detected by RT-PCR and Western blotting, respectively.</p><p><b>RESULTS</b>Four shRNA vectors were successfully constructed as confirmed by DNA sequencing and the enzyme digestion analysis. Among the 4 recombinant vectors, pGPU6/GFP/Neo-shRNA AMPKα2(3) showed the strongest gene silencing effect and down-regulated the protein expression of AMPKα2 by 63% in the transfected cells.</p><p><b>CONCLUSION</b>Transfection with pGPU6/GFP/Neo-shRNA AMPKα2(3) results in effective inhibition of AMPKα2 gene expression in SH-SY5Y cells, which provide a means for studying AMPK-mediated cell injury.</p>

Roles of phosphorylated extracellular signal-regulated kinase in rats with incisional hyperalgesia / 中华神经医学杂志

Objective To investigate the changes of phosphorylated extracellular signal-regulated kinase (p-ERK) expression in the immunoreactive cells of the spinal dorsal hom after plantar incision,and explore the effects of intrathecal administration of MEK inhibitor U0126 on physiological pain threshold in rat models with incisional pain.Methods Thirty-two male SD rats were equally randomized into control group (C group),incisional pain group (I group),intrathecal U0126 group (Ugroup) and intrathecal DMSO group (D group).Twenty-μL physiological saline was injected into the rats of the C group and I group,respectively.Ten-μL DMSO and U0126 were injected into the rats in the U group and D group,respectively.Rat models with incisionai pain were induced in the other 3 groups except the C group.Mechanical hyperalgesia were evaluated by paw-pressure before and 2,24 h and 2 d after the inducement.Another 24 rats were treated as the above method and equally divided into 4 groups; the numbers of p-ERK immunoreactive cells in the dorsal horn were quantified to determine the ERK activation 2 and 24 after the model inducement.Results The paw-pressure threshold in I group and D group 2 and 24 h,and 2 d after the incision,and that in U group 2 and 24 h after the incision were significantly decreased as compared with that in C group (P<0.05); that between I group and D group showed no significant difference (P>0.05); that in the U group was obviously higher than that in the I group and D group at the same time points (P<0.05).Significantly increased numbers of p-ERK immunoreactive cells in the I group and D group were observed as compared with those in the C group (P<0.05); those in the U group was obviously decreased as compared with those in the I group and D group at the same time points (P<0.05).Conclusion Plantar incision-induced mechanical hyperalgesia can be prevented by intrathecal injection of U0126 through decreasing the expression of p-ERK positive cells,indicating that ERK pathway in the spinal dorsal horn involves in the incision-induced mechanical hyperalgesia in rats.