A rat model of bone cancer pain and the expression of voltage gated sodium channel Nav1.8 in dorsal root ganglion / 解放军医学杂志

ABSTRACT

Objective To establish a model of bone cancer pain in rats and to evaluate the role of voltage gated sodium channel Nav1.8 in the course of bone cancer pain by observing the expression of Nav1.8 in dorsal root ganglion in the model with bone cancer pain.Method Female SD rats received intra-tibial injection of syngenetic Walker256 mammary gland carcinoma cells in different concertration(103/?l,104/?l or 105/?l).Pain threshold of mechanical hyperalgesia and thermal hyperalgesia were tested at 1d,3d,5d,7d,10d,and 14d after cell injection.The development of the bone tumor was verified by pathological examination 14d after cell injection.The L5-6 DRG was obtained from normal rats and rats with bone cancer pain.Expression of voltage gated sodium channel Nav1.8 was investigated by RT-PCR.Result Intra-tibial injection of Walker256 cells produced a rapidly expanding tumor within the boundaries of the tibia,causing marked remodeling of the bone.Rats receiving intra-tibial injection of Walker256 cells displayed gradual development of both mechanical and thermal hyperalgesia 7-14 days after the injection.The expression of Nav1.8 in DRG was up-regulated in the model of bone cancer pain in rats(P