Study On The Mechanism Of SP And CGRP In The Chronic Pain Of Knee Joint

Objectives-To investigate the effects of SP and CGRP in thechronic knee pain with osteoarthritis.Methods-47 patients with knee osteoarthritis, who reportedjoint pain, and 18 health adults as control group were included inthe study. The mean age of the patients was 53±13 (range 44-72) years,and the mean duration of disease was 5.6±2.8 ( range 1.5-14)years.while the control group'ages ranged from 33 to 64 years, withan average of 47±15 years. Synovial tissue and synovial fluidsamples was collected from these cases. Respectively , Synovialsamples were stained with an immunohistochemical method usingantisera against neuropeptides. the concentration of SP and CGRPwas measured in the synovial fluid samples using a radioimmunoassaymethod. Statistical analysis was performed using SPSS 11.5 forwindows kit. Preoperative permission was obtained from all patients.Results-the study showed Substance P immunoreactive nervefibers in 26 of 47 (55%) osteoarthritis Synovial samples, in 7 of24 (29%) control group samples (p < 0.05); while CGRP immunoreactivenerve fibers in 24 of 47 (51%) Synovial samples, in 5 of 24 (21%)control group samples (p < 0.05). Synovial cells staining intensityand the percentage of positive staining cells and The area ofsynovial cell lining in the patients with osteoarthritis was higherthan that of normal controls . Finaly, the concentration of SPin the synovial fluid samples from patients with osteoarthritisexceeded the level of SP in the samples from the healthgroup(p<0.05),while there was not a significant difference in theconcentration of CGRP between the patients and the control group(p﹥0.05).Conclusion-The effect of the sensory Neuropeptides SP,CGRPis significant on the pain mechanism of the knee with osteoarthritis.