Experimental Research Of Nandrolone Phenylpropionate In The Treatment Of CRPS On The Rat Model

Objective:This research is intended to evaluate the analgesic effect of nandrolonephenylpropionate on the rat model of complex regional pain syndrome, and brieflydiscuss the analgesic mechanism of the nandrolone phenylpropionate,so as to provid theexperimental evidence for clinical application of phenylpro-pionate nandrolone in thetreatment of complex regional pain syndrome.Methods:Forty-eight healthy adult SD rats were randomly divided into fourgroups equally. Rats were anesthetized over a3h period with chloral hydrate. Afterinduction of anesthesia,a O-ring with5mm internal diameter was placed around the rat’sright hindlimb just proximal to the ankle joint. The O-rings were selected to produce atight-fit pressure about350mmHg,and were left on the limb for3h. The rats in thesham group received exactly the same treatment,except that the O-ring looselysurrounded the ankle,and did not occlude blood flow to the hindpaw. Rats of group Bwere injected with1ml sterile water intraperitoneally every other day,to days-21aftersurgery. Rats of group C were injected with salmon calcitonin（2IU/Kg） intraperitoneally,every other day,to days-21after surgery. And rats of group Dwere injected with nandrolone phenylpropionate （5mg/Kg） intraperitoneal-ly,everyother day,to days-21after surgery.Then general observation, pain behavior,serum substance P, and distal bone mineral density of the tibia were measured at thespecific observation points. By the above indicators, assessing the analgesic effectof nandrolone phenylpropionate on rat model of complex regional pain syndrome. Allexperimental data were analyzed by the software of SPSS12.0.Results:1.General observation: After modeling, the rats in group B, C and Dhad a limping gait.At weeks-3after surgery, the claudication symptom of the rats ingroup C and D was better than the rats in group B. And the rats in group B had epilation and scaling phenomenon.2.Spontaneous pain:At one day after the modeling,spontaneous pain was checked.The spontaneous pain of injuried group is more serious than the group A（p＜0.05）.3.Mechanically induced pain: Since the7days after modeling,the pain thresholdof group C and D was significantly higher than group B（p＜0.05）. To days-21aftersurgery, no significant difference was found between the two treatmentgroups and group A. At each observation point, no significant difference was foundbetween group C and group D.4.Paw withdrawal latency: Since the7days after modeling, the paw withdrawallatency of group C and D was significantly higher than group B （p＜0.05）,but always lower than group A. At each observation point, no significant differencewas found between group C and group D.5.Substance P: Since the7days after modeling, the level of substance P of groupC and D was significantly lower than group B（p＜0.05）, but always higher than groupA. At each observation point, no significant difference was found between group C andgroup D.6.The tibia Ca²⁺average density testing: At twenty-one days after the modeling,the distal Ca²⁺average density of the right tibia of group B is significantly lower thangroup A（p＜0.05）. No significant difference was found in other groups.Conclusion:1.Ischemia reperfusion model can simulate the pathophysiological processof CRPS, and modeling process is easy to operate.2.Since the7days after modeling, nandrolone phenylpropionate can signifi-cantlyimprove pain behavior index of the experimental animal, and reduce the expressionof substance P.3.Nandrolone phenylpropionate can increase the local Ca²⁺average density andmuscle strength of experimental animal, and prevent the development of CRPS.In summary, the study shows that nandrolone phenylpropionate has a goodeffect on CRPS with the rat model. So the clinical efficacy of nandrolonephenylpropionate is worthy of further experimental study.