Relationship between Nerve Fibers Distribution in Eutopic Endometrium and the Pain Symptom in Endometriosis

Objective:To investigate the localizations of PGP9.5,SP and NGF in eutopic endometrium of endometriosis; and to explore the relationship between the distribution of endometrial nerve fibers and the pain associated with endometriosis.Methods:Forty-five endometriosis patients were divided into 24 cases with pain, which included 4 cases with mild pain,7 cases with moderate pain and 13 cases with severe pain, 21 cases without pain according to the visual analogue scale method (VAS).The density of PGP9.5-nerve fibers, and the average optical density of SP and NGF were detected by immunohistochemical staining, and their correlation with scores of the VAS were also analyzed.Results: The density of PGP9.5-nerve fibers, and the average optical density of SP and NGF in pain group of endometriosis were significantly higher than those in painless group and in control group (P0.05).The density of PGP9.5-nerve fibers, and the average optical density of SP and NGF in severe pain group were significantly higher than those in mild pain group and moderate pain group(P0.05), and both of them were significantly correlated with scores of VAS(r=0.745,0.624,0.628,respectively;P0.05).Conclusions: The distribution of nerve fibers in ectopic endometrium of endometriosis patients is abormal.The expression of nerve fibers is related to the pain severity, and abnormal high expression of nerve fibers was one of the reseasons causing the pain in endometriosis.