Zahra Farahani - PhD candidate in Physiology, Physiologydivision of Basic Sciences Department, School of Veterinary Medicine,Shiraz University
Mahnaz Taherianfard - Professor, Physiology division of Basic Sciences Department, School of Veterinary Medicine, Shiraz University,Shiraz-Irantaherian
Mohamad Mehdi Naderi - Associate Professor, Avicenna Research Institute, Tehran-Iran
Hortensia Ferrero - Biologist, Institute of treatment and diagnosis of uterine diseases, IVI Foundation, Valencia- Spain

Background and Aim : Of all the symptoms, pain is the most frequently reported symptom involving inendometriosis. In the present study, the association between serum, peritoneal fluid (PF) and dorsal rootganglion (DRG) neurotrophins (NTs) and the pain was evaluated in rat models of endometriosis.Methods : Thirty Sprague Dawley female rats, weighing 150-250 gr, were selected and kept in a standardcondition with 12 h dark-light and 20-24C temperature. All the rats were randomly assigned to 3 groupsas follow: Control group, intact rats; Sham group, the operation was done without endometriosis induction;endometriosis group, endometriosis induction was done. The formalin test was done before and after theendometriosis induction. The assessments of brain-derived neurotrophic factor (BDNF), nerve growthfactor (NGF), calcitonin gene-related peptide (CGRP), and substance P levels by enzyme-linkedimmunosorbent assay (Elisa) were carried out. The data were analyzed by one-way ANOVA; the Tukey’stest was used as the post-hoc test.Results : Endometriosis induction could significantly increase the mean nociceptive score in theendometriosis group in all the three phases of the formalin test. According to the present data, theconcentration of DRG-CGRP, BDNF, and NGF in the endometriosis group was significantly higher thanthat of the other groups while serum-BDNF, substance P, and NGF were significantly lower in this groupcompared to other groups. The concentrations of PF-BDNF and substance P were significantly lower thanthose of other groups. Conclusion : The present results showed that endometriosis induction could lead to hyperalgesia in theformalin test. This may be related to the significant increases in the BDNF and CGRP in DRG.

Endometriosis; Brain-derived neurotrophic factor; nerve growth factor; calcitonin gene-related peptide; substance P; rats