Antinociceptive action of botulinum toxin type A in carrageenan-induced mirror pain

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• 作者：V. Drinovac Vlah ; L. Bach-Rojecky ; Z. Lacković
• 关键词：Botulinum toxin A ; Mirror pain ; μ ; opioid antagonist ; GABAA antagonist ; Capsaicin ; sensitive neurons ; Cleaved SNAP ; 25
• 刊名：Journal of Neural Transmission
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：123
• 期：12
• 页码：1403-1413
• 全文大小：3,052 KB
• 刊物类别：Medicine
• 刊物主题：Medicine & Public Health
  Neurology
  Pharmacology and Toxicology
  Psychiatry
  
• 出版者：Springer Wien
• ISSN：1435-1463
• 卷排序：123

文摘

“Mirror pain” or mirror-image pain (MP) is pain opposite to the side of injury. Mechanism and frequency in humans are not known. There is no consent on therapy. Here we report that unilaterally injected botulinum toxin type A (BT-A) has bilateral effect in experimental MP, thus deserves to be investigated as therapy for this condition. We examined the localization of BT-A’s bilateral antinociceptive action in MP induced by 3 % carrageenan intramuscular injection in Wistar rats. BT-A was applied peripherally (5 U/kg), into ipsilateral or contralateral hind paw pad (i.pl.) and centrally (1 U/kg), at spinal (intrathecally, i.t.) or supraspinal (intracisternally, i.c.) level. Additionally, we examined the involvement of central opioid and GABAergic systems, as well as the contribution of peripheral capsaicin-sensitive neurons to BT-A’s bilateral antinociceptive effect. Ipsilateral i.pl. and i.t. BT-A reduced the bilateral mechanical sensitivity to von Frey filaments, while contralateral i.pl. and i.c. treatments had no effect on either tested side. Bilateral antinociceptive effect of ipsilateral i.pl. BT-A was prevented by μ-opioid antagonist naloxonazine (1.5 μg/10 μl) and GABA_A antagonist bicuculline (1 μg/10 μl) if applied at the spinal level, in contrast to supraspinal application of the same doses. Local treatment of sciatic nerve with 2 % capsaicin 5 days following BT-A i.pl. injection caused desensitization of sciatic capsaicin-sensitive fibers, but did not affect bilateral antinociceptive effect of BT-A and the presence of cleaved SNAP-25 at the spinal cord slices. Present experiments suggest segmental actions of peripheral BT-A at spinal level, which are probably not solely dependent on capsaicin-sensitive neurons.