0bjective To study the expression of Fas in hippocampus of cerebral ischemia-reperfusion rats after treatment with monosialoganglioside (GM1). Methods Seventy-two SD rats were randomly divided into sham group (n=8), GM1 treatment group (n=32) and ischemia-reperfusion (I/R) group (n=32). According to the different time points (6 h, 12 h, 24 h and 3 d) of I/R, there were four subgroups in GM1 and I/R groups respectively. The expression of Fas in hippocampus was examined by immunochemistry and Western blot methods in all groups. Results Results of immunochemistry method showed that there was a little expression of Fas (the mean optical density was 0.17±0.02) in hippocampus of sham group, and the positive expression of Fas at different time points were increased significantly after reperfusion. The mean values of opti-cal density at different time points were 0.42±0.11, 0.51±0.13, 0.55±0.13 and 0.62±0.15 in I/R group, which reached to the peak at 3 d . The positive expression of Fas at different time points were significantly decreased in GM1 group (0.29 ± 0.09, 0.34±0.11, 0.37±0.12 and 0.43±0.12) than that of I/R group (P＜0.05). Conclusion Monosialoganglioside participated in the pathogenesis of cerebral ischemia-reperfusion injury by down-regulating the expression of Fas.

98% amino acid identity.There are 28 different amino acids between them,with 7 of which locating in the region encoded by exon6A or exon6.Alternative splicing of exon18 was not found in the gene cloning of human brain Nav1.5/SCN5A,which was different from human heart Nav1.5/SCN5A,but a novel alternative splicing lacking exon24 was first found.The two variants were detected in similar ratio in brain,but they were proved to relate to age development in heart tissue.The exon24 of human Nav1.5/SCN5A has 54 nucleotides,encoding 30 amino acid residues,and are located in human chromosome 3P21.This alternative splicing was also found in other tissues other than heart and brain.The expression pattern of the two variants in different tissues was different when detected by competitive PCR method and it was also changing with age development.Furthermore,Nav1.5/SCN5A mRNA was detected in 16 different tissue types of Wistar rats(P80) by reverse polymerase chain reaction(RT-PCR) .These results suggest that Nav1.5 Na+ channels in human brain are encoded by new variants of Nav1.5/SCN5A and its mRAN is more widely expressed than previously thought.The study is useful for making further investigation in the functional analysis of Nav1.5 Na+ channels in different tissues.

Objective:To study the expression of adult and neonatal Nav1.5 isoforms in the dorsal root ganglia (DRG) neurons of rats with spared nerve injury (SNI) . Methods:The expression of adult and neonatal Nav1.5 isoforms in the DRG neurons of rats with SNI was detected by RT-PCR, DNA sequencing, restriction enzyme digestion, immunohistochemistry and immunofluo-rescence methods. The expression of PKC-γwas detected by Western blot. Results:Both adult and neonatal Nav1.5 isoforms were expressed in the DRG neurons, but their expression ratio was approximately 2.5∶1. In SNI rat models, the expression of both adult and neonatal Nav1.5 isoforms decreased by approximately a half in both mRNA and protein levels. In contrast, the expression of PKC-γincreased by approximately one-fold. Conclusions:Both adult and neonatal Nav1.5 isoforms expressed in the DRG neurons of rat,but their expression levels decrease in pain models. The up-regulation of PKC-γmay directly or indirectly down-regulate the expression of Nav1.5 isoforms in SNI rat models,which may further involve in the pathological process of neuropathic pain.