Does Low Reactive LASER Therapy Affect on Anti-nociception or Anti-inflamation?

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 11671471
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Anesthesiology/Resuscitation studies
• Research Institution: Hokkaido University
• Principal Investigator: KEMMOTSU Osamu Hokkaido Univ.Grad.School of Med., Prof., 大学院・医学研究科, 教授 (70045433)
• Co-Investigator(Kenkyū-buntansha): HARASAWA Katsumi Hokkaido Univ. Medical Hospital, Inst., 医学部・附属病院, 助手 (30271662)
• Project Period (FY): 1999 – 2000
• Keywords: low reactive level laser / allodynia / neuropathic pain / inflammation

Research Abstract

Our prior purpose in this year is to finish establishing our neuropathic pain model in order to measure the effect of low reactive level laser therapy (LLLT). The neropathic pain model was made by ligating the fifth and the sixth lumbar nerves of partially raminected rats under anesthesia. However, 24 rats whose fifth and sixth lumbar nerves were both ligated could not live for a long time enough to measure the effect of ligation, because of unknown reasons. Therefore, we came to ligate just the fifth lumbar nerve and tested whether the modified model exerted allodynia on the related area. And we began to use SD rats instead of Wistar strain rats. In the modified model, the threshold against thermal stimuli became shorter for about 2 sec in the hind limb of the ligated side compared with the other side. When we treated the neuropathic pain rats by LLLT to the hind paw for 10 min with 150 mW laser therapy, the thresholds tended to be normalized. On the other hand, when we treated the rats by applying LLLT to the related spinal cord area where the fifth lumbar nerve was originating, we could not obtain enough data to prove the effect of LLLT on the thresholds.