Journal Article

Estrogen affects neuropathic pain through upregulating N-methyl-D-aspartate acid receptor 1 expression in the dorsal root ganglion of rats

Chao Deng Ya-juan Gu Hong Zhang Jun Zhang

2017

Overview

Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D（-）-2-amino-5-phosphonopentanoic acid（AP-5）,or both once daily for 15 days.Compared with injured drug na？ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity（as assessed by immunohistochemistry） and protein（as determined by western blot assay） in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.

• Publisher: Medknow Publications and Media Pvt. Ltd,Medknow Publications & Media Pvt. Ltd,Department of Anesthesiology,First Affiliated Hospital,School of Medicine,Shihezi University,Shihezi,Xinjiang Uygur Autonomous Region,China%Department of Obstetrics and Gynecology,First Affiliated Hospital,School of Medicine,Shihezi University,Shihezi,Xinjiang Uygur Autonomous Region,China%Department of Genetics,School of Medicine,Shihezi University,Shihezi,Xinjiang Uygur Autonomous Region,China,Medknow Publications & Media Pvt Ltd,Wolters Kluwer Medknow Publications
• Subject: 17β-雌二醇 / Acids / Care and treatment / Drug withdrawal / Estrogens / Health aspects / Hyperalgesia / Laboratory animals / N-methyl-D-aspartate / N-甲基-D-天冬氨酸受体 / nerve regeneration; peripheral nerve injury; estrogen; 17β-estradiol; N-methyl-D-aspartic acid receptor 1; pain; sciatic nerve; chronic constriction injury; neuropathic pain; D(-)-2-amino-5-phosphonopentanoic acid; dorsal root ganglion; spinal cord; immunoreactivity; western blot assay; neural regeneration / Ostomy / Pain / Pain management / Peripheral nervous system diseases / Rodents / 免疫组化检测 / 大鼠 / 神经病理性痛 / 神经痛 / 脊髓背根神经节 / 雌激素