Related Experiment Videos
The spinal phospholipase-cyclooxygenase-prostanoid cascade in nociceptive processing.
Camilla I Svensson1, Tony L Yaksh
1Department of Anesthesiology, University of California, San Diego, La Jolla, California 92093-0818, USA. csvensson@ucsd.edu
Annual Review of Pharmacology and Toxicology
|January 25, 2002
Summary
Spinal phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2) inhibitors reduce pain states. The primary pain relief mechanism involves modulating constitutive spinal COX-2, not upregulated forms.
Area of Science:
- Neuroscience
- Pharmacology
- Pain Research
Background:
- Peripheral injury and inflammation induce facilitated pain states.
- Spinal phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2) pathways are implicated in pain signaling.
- Prostaglandins, produced by COX enzymes, affect spinal neuronal excitability.
Purpose of the Study:
- To investigate the role of spinal PLA2 and COX-2 in facilitated pain states.
- To determine the contribution of constitutive versus upregulated spinal COX-2 to antihyperalgesic effects.
Main Methods:
- Administration of intrathecal PLA2 and COX-2 inhibitors.
- Assessment of pain states induced by peripheral stimuli and direct spinal receptor activation.
- Analysis of spinal COX-2 expression patterns.
Main Results:
- Intrathecal PLA2 and COX-2 inhibitors, but not COX-1 inhibitors, attenuated facilitated pain.
- These effects were observed in both inflammation-associated and non-inflammatory hyperalgesic states.
- Antihyperalgesic activity of COX-2 inhibitors occurred before significant COX-2 upregulation.
Conclusions:
- Constitutive spinal COX-2 plays a significant role in mediating antihyperalgesic effects of COX-2 inhibitors.
- Modulation of constitutive spinal COX-2 is a primary mechanism for pain relief.
- Spinal PLA2 and COX-2 pathways are critical targets for managing facilitated pain.