The effect of a peripheral block on inflammation-induced prostaglandin E2 and cyclooxygenase expression in rats.

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Beloeil H, Gentili M, Benhamou D, Mazoit JX

The effect of a peripheral block on inflammation-induced prostaglandin E2 and cyclooxygenase expression in rats.

Anesth Analg. 2009 Sep;109(3):943-50. doi: 10.1213/ane.0b013e3181aff25e.

PubMed ID

19690271 [ View in PubMed

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Abstract

BACKGROUND: Peripheral inflammatory pain is associated with an upregulation of spinal cord COX-2 (cyclooxygenase-2), with a subsequent increase in central prostaglandin E2 (PGE2) levels associated with the development of hyperalgesia. In this study, we evaluated the effect of bupivacaine administered via a nerve block or via a systemic route on the spinal expression of PGE2 and COX in a model of peripheral inflammation in rats. METHODS: All rats randomly received three injections: 1) a left subcutaneous hindpaw injection (0.2 mL with either carrageenan 2% w/v or saline), 2) a left sciatic block (0.2 mL with either bupivacaine 0.5% or saline), and 3) a systemic injection (subcutaneous interscapular with 0.2 mL with either bupivacaine 0.5% or saline). Local edema, thermal, and mechanical hyperalgesia as well as cerebrospinal fluid PGE2 concentration and COX-1 and COX-2 expression in the spinal cord in dorsal root ganglions were measured. RESULTS: We confirmed that a bupivacaine block attenuates hyperalgesia and local inflammation in a model of inflammatory pain. This effect was associated with an inhibition of the increase in COX-2 expression induced by peripheral inflammation in dorsal root ganglions and cord. The subsequent production of PGE2 in cerebrospinal fluid was also impaired. Systemic bupivacaine did not modify either the hyperalgesia and local inflammation or COX expression. CONCLUSION: These results constitute a key element strongly suggesting that local anesthetics act at a different level when administered systematically or via a nerve block.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Bupivacaine	Prostaglandin E2 receptor EP1 subtype	Protein	Humans	Unknown	Other/unknown	Details