The Effect of Nerve Growth Factor on the Genesis of Neuropathic Pain

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07671672
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Anesthesiology/Resuscitation studies
• Research Institution: Miyazaki Medical College
• Principal Investigator: UNO Takeshi Miyazaki Medical College, Medical Department, Associate Professor, 医学部, 助教授 (70038842)
• Co-Investigator(Kenkyū-buntansha): KOSAI Kazuko Miyazaki Medical College, Medical Department, Instructor, 医学部, 助手 (00234740)
• Project Period (FY): 1995 – 1996
• Keywords: Nerve Growth Factor / Neuropathic Pain

Research Abstract

We observed the effect of nerve growth factor (NGF) on a noxious behavior in rat neuropathic pain model. [Methods] Male Sprague-Dawley rats weighing 200-250g at the biginning of the experiment were used. The rats were anesthetized with sodium pentobarbital (50mg/kg, i.p.) , and the right sciatic nerve was ligated with 4-0 chromic gut suture under microscopic observation. At the level of the mid-thigh, four loose ligatures were done just proximal to its trifurcation with 1-2mm distance between each ligature. Then, osmotic minipump connected to sillicone tube was implanted subcutaneously in the back for the continuous infusion of NGF (human recombinant NGF,1mug/day) or vehicle (sodium phosphate buffer, pH=7.0, containing 10%BSA) for 2 weeks. Thermal hyperalgesia was assessed before sciatic nerve ligation and 1,3,5,7 postoperative day. Thermal noxious threshold was determined to measure withdrawal latency against radiant heat which was applied to a plantar surface of each hind paw by using of plantar test (UGO BASILE) The magnitude of hyperalgesia was estimated by difference score (DS) which was obtained by subracting the latency of the opposite side from that of the ligated. Therefore, negative scores indicate thermal hypralgesia. [Results] DS in control group increased negatively from 3 to 7 postoperative day, whereas DS in NGF group did not increase negatively compared to a control. [Conclusion] We concluded that NGF could be useful for the treatment of neuropathic pain in clinical situation.