RESUMO
Pain is the most pronounced complaint of women with endometriosis, however the underlying mechanism is still poorly understood. In the present study, the authors evaluate the effect of transient receptor potential vanilloid type 1 (TRPV1) of dorsal root ganglia (DRG) on endometriosis-associated pain. A total of 36 SD rats were randomly divided into a sham group (n=9) and a Model group (n=27), accepted autotransplanted pieces of fat or uterus to the pelvic cavity. At 4 weeks, the Model group was randomly subdivided into the following groups: ENDO group (no treatment, n=9), BCTC group (Model + BCTC, an antagonist of TRPV1, n=9), Vehicle group (Model + cyclodextrin, the vehicle of BCTC, n=9). Tailflick test was performed prior to surgery, 1 h prior to and following treatment of BCTC or cyclodextrin. The expression of TRPV1, substance P (SP), calcitonin generelated peptide (CGRP) in L1L6 DRG was measured via immunohistochemistry, western blotting and RTqPCR. The results indicated that the Model group exhibited a signiï¬cant decrease in tail flick latency compared to presurgical baseline, and the expression of TRPV1, SP, CGRP protein and mRNA in L1L6 DRG signiï¬cantly increased compared to the sham group. BCTC significantly improved tail flick latency, and downregulated the expression of TRPV1, SP and CGRP protein and mRNA levels in L1L6 DRG compared to ENDO group. However, there were no significant differences of those in Vehicle group compared with the ENDO group. Taken together, the current study provides evidence that TRPV1 expressed in DRG may serve an important role in endometriosis-associated pain.