Reversion of down-regulated mRNA expression for Nav1.8 in dorsal root ganglia of rats with neuropathic pain by APA microcapsulized BCCs subarachnoid transplantation / 中国药理学通报

ABSTRACT

AIM To invesigate the effect of subarachnoid transplantation of APA microcapsulized bovine chromaffin cells (BCCs) on mRNA expression for Nav1.8 in the dorsal root ganglia neurons(DRG) of rats with neuropathic pain by means of in situ hybridization. METHODS SD rats were randomly divided into four groups of five. Normal rats were used as control group (group C). Rats with right sciatic nerve been ligated were used as CCI group. Five to six hundred empty APA microcapsules(group APA) or 5?10 6 APA microcapsulized BCCs (group APA-BCCs) were grated into subarachnoid space of CCI rats 7 days after operation. Allodynia and hyperalgesia were measured by Von-Frey filaments and CO 2 laser 7 days after transplantation. DRG in lumbar four and five was taken out and 15 ?m freezing sections were made 7 days after tansplantation. Sections was used to detect mRNA expression for TTX-resistent Na + Nav1.8 by in situ hybridization with Dig-labeled RNA probe. RESULTS The mRNA hybridization signal for Nav1.8 in DRG of group CCI and group APA was lower than that of group C. The expression of mRNA for Nav1.8 in DRG was higher in group APA-BCCs than that in group CCI and group APA with abatement of allodynia and hyperalgesia. There was no difference in the mRNA hybridization signal for Nav1.8 in DRG between group APA-BCCs and group C. CONCLUSION mRNA expression for Nav1.8 in DRG of CCI ratswas down-regulated. APA microcapsulized BCCs grafting can reverse the down-regulation of mRNA expression for Nav1.8 in DRG of CCI rats. Restoration of mRNA expression for Nav1.8 in DRG contributes to the analgesic effect of subarachnoid transplantation of APA microcapsulized BCCs.