[Expression of transient receptor potentials of vanilloid subtype 1 and pain in endometriosis].

OBJECTIVE: To investigate the expression of transient receptor potential vanilloid subtype 1 (TRPV1) in uterosacral ligament and its correlation with pain in endometriosis. METHODS: Total of 54 patients undergoing endometriotic lesions excision in uteroscaral ligament by laparoscopy due to pelvic pain were enrolled in this study. According to visual analogue scale (VAS) scores, 27 patients with VAS 5-10 were in group A and 27 patients with VAS 0-4 were in group B. In the mean time, 20 patients with dysmenorrhea without endometriosis (VAS: 0-4) were matched as group C. Specimens (including the sacro-ligaments of 20 women without endometriosis) were immunostained with specific antibodies of TRPV1. Western blot and real time PCR were performed to detect TRPV1 expression in endometriosis lesions and control group. RESULTS: (1) Immunohistochemnistry: the positive area of TRPV1 was found in endometriotic lesions in uterosacral ligament in group A, B and tissue of uterosacral ligament group C. The semi-qualitification of TRPV1 expression were 3 in group A, 1 in group B and 1 in group C by immunohistochemistry staining. There was significantly different expression between group B and group A (P = 0.005) or group C (P = 0.027). (2) mRNA expression:the expression of TRPV1 was 1.84 in group A, 0.80 in group B, 0.24 in group C, respectively. With higher VAS scores, the expression of TRPV1 exhibited increasing trends. The expression of TRPV1 mRNA was higher in group A than that in group B (P = 0.022). There was statistically different expression between group B and group C (P = 0.031). (3) Western blot: the expression of TRPV1 protein was 0.63 in group A, 0.19 in group B, 0.02 in group C. There was significant differences between group A and group B (P = 0.022), and between group B and group C (P < 0.01). CONCLUSION: The expression of TRPV1 was correlated with the degree of pain in patient with endometriosis.