The role of the descending inhibitory system in endogenous analgesia

2016 Fiscal Year Final Research Report

• Project/Area Number: 26670678
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Anesthesiology
• Research Institution: Fukushima Medical University (2015-2016); Gunma University (2014)
• Principal Investigator: Obata Hideaki 福島県立医科大学, 医学部, 教授 (20302482)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ノルアドレナリン / 内因性鎮痛 / 下行性抑制系 / 神経障害性疼痛

Outline of Final Research Achievements

We examined the change in endogenous analgesia (NSIA) over time after right L5 spinal nerve ligation (SNL) in rats. NSIA was attenuated 5 and 6 w after SNL accompanied with dysfunction of the descending noradrenergic inhibition. These were recovered by five daily injections of amitriptyline (10 mg/kg/day). These data suggest that endogenous analgesia in neuropathic pain states is strongly decreased from a certain time after nerve injury, and amitriptyline reverses the attenuation of endogenous analgesia.
In the clinical study, we examined the effect of pregabalin in endogenous analgesia using CPM. CPM were measured before and after pregabalin or placebo administration. Fifty-nine healthy subjects were randomly assigned to either a pregabalin group or a placebo group. The correlation between initial CPM and the change in CPM was significantly strong in pregabalin group compared to placebo group. Pregabalin could be more effective in subjects with the lower endogenous analgesia.

Free Research Field

麻酔科学