Prostaglandins and pain—sites of action
| • Peripheral sensors? Lipoxygenase products? |
| • Peripheral nerves: |
| (i) PGs sensitise C fibres to analgesia |
| (ii) Monoclonal AB to PG given iv reduces hyperalgesic behaviour7 |
| • Spinal cord |
| (i) Peripheral inflammation induces NMDA, COX-2 mRNA, PGs and lipoxygenase products by spinal cord at relevant segment level. |
| (ii) Exposing cord to PGs induces hyperalgesia and allodynia: ?differential nerve effect. |
| (iii) Intrathecal NSAIDs, at doses 1% of systemic, abolish inflammatory responses and pain in some models8 |
| • Brain: Many stimuli upregulate COX-2 and COX-1, various loci. |
PGs, prostaglandins; COX, cyclooxygenase; NMDA,N-methyl-d-aspartate.