Effect of neurolytic nerve block on systemic carrageenan-induced inflammatory response in mice

Abstract

Background. Local tissue inflammation caused by injury or inflammatory processes may be reduced by section or local anaesthetic block of the nerve innervating the inflamed area. Methods. Using a neurolytic nerve block, we assessed the systemic inflammatory response elicited by a local injection of carrageenan in mice. Sixty mice received a unilateral sciatic nerve block with 70% ethanol followed 5 days later by an injection of carrageenan on the ipsilateral or contralateral hind paw. Whole blood was sampled 15 h after carrageenan injection. Results. Fifty-six animals had a complete nerve block. Tumour necrosis factor-alpha (TNF-α), interleukin 1β (IL-1β) and interleukin 10 (IL-10) concentrations were measured in the plasma of 20 mice (10 in the ispilateral group and 10 in the contralateral group). In the remaining 36 mice (18 in each group), blood was cultured for 24 h in the presence of lipopolysaccharide or Staphylococcus aureus extract. TNF-α and IL-1β production in the supernatant were, on average, 30% lower in the ispilateral group than in the contralateral group. Conclusion. A prolonged nerve block decreases the systemic consequences of the local inflammatory reaction elicited by carrageenan injection. © The Board of Management and Trustees of the British Journal of Anaesthesia 2005. All rights reserved.