The Study Of Gabapentin Combined With Morphine In Analgesia Of Neuropathic Pain Rabbit

Objective The aim of this study was to investigate the efficacy of gabapentin combined with morphine in treating neuropathic pain rabbits, induced by chronic constriction injury (CCI), and the alteration of the expression of serum inflammatory cytokines tumor necrosis factor -alpha,interleukin-6 of the rabbits and the alteration of the expression of serum positive Cluster of differentiation 4 and 8.Methods Twenty-five male rabbits were received CCI. After a week, twenty successful neuropathic pain models were selected from twenty-five operated hind paws .Which were randomly divided to saline(NS),gabapentin (G),morphine(M) and combination of gabapentin with morphine(MG) with 5 rabbits each .Each group administration with normal saline,gabapentin caps,morphine tablets and combination of gabapentin caps with morphine tablets respectively two weeks . We observed the change of the operated hind paws , measured blood serum 5-HT,NE,TNF-α,IL-6,CD4~+,CD8~+ by ELISA. Result①rabbit spontaneous pain change: after gastric gavage with gabapentin caps,morphine tablets and combination of gabapentin caps with morphine tablets, pain improved to varying degrees ,the group MG appeared earlier than the others, the group G was earlier than group M ,but the group NS did not changed.②Neurotransmitter change: Compared with 1d before CCI, 5-HT,NE expression increased at 4 groups after a week of CCI,all time points in group NS and after a week administration in group M,G(P<0.05). Compared with the group NS, after one week and two weeks administration in group M,G,MG, the neurotransmitter was decreased(P<0.05). Compared with the group M,G at the time point after one week administration ,the group MG 5-HT,NE expression decreased(P<0.05), after two weeks administration in group M,G,MG had no significantly difference expression of blood serum 5-HT,NE (P>0.05).③Serum inflammatory cytokines change: Compared with 1d before CCI, TNF-α,IL-6 expression increased at 4 groups after a week of CCI,all time points in group NS and after a week administration in group M,G(P<0.05). Compared with the group NS, after one week and two weeks administration in group M,G,MG, TNF-α,IL-6 was decreased(P<0.05). Compared with the group M,G at the time point after one week administration ,the group MG expression of blood serum TNF-α,IL-6 decreased(P<0.05), after two weeks administration in group M,G,MG had no significantly difference expression of blood serum TNF-α,IL-6(P>0.05).④Serum CD4~+,CD8~+ change: Compared with 1d before CCI, CD4~+,CD8~+expression increased at 4 groups after a week of CCI(P<0.05). After one week administration ,Compared with after a week CCI, CD4~+,CD8~+expression decreased slightly in the group MG,M,G, it has no significant difference(P>0.05), the group NS expression of blood serum CD4~+,CD8~+ decreased(P <0.05); After two weeks administration in group MG,G the expression of serum CD4~+,CD8~+ decreased slightly compared with after a week administration, it has no significant difference(P>0.05). Compared with after a week CCI, CD4~+,CD8~+expression decreased significant in the group M ,in group M, expression of blood serum CD4~+,decreased(P<0.05). compared with 1d before CCI, and the same time in the group G,MG,NS. After two weeks administration, the group NS serum CD4~+,CD8~+expression did not decrease, compared with after a week administration, there had no significantly difference(P>0.05).Conclusion①The gabapentin combined with morphine can produce better analgesic efficacy than the double gabapentin and morphine, can effectively relieve neuropathic pain rabbits'pain induced by chronic constriction injury , the was better.②And at the same time gabapentin combined with morphine can decrease neuropathic pain rabbits'expression of the inflammatory cytokines TNF-α,IL-6.③At the same time gabapentin combined with morphine can delay the reduction of neuropathic pain rabbits'expression of serum CD4~+,CD8~+.