Distribution of Cyclooxygenase-3 (Cox-3) in Rat Nervous System,SEHAM A. ABD EL-ALEEM, MOSTAFA ABDEL-HAMID, DANIEL L. SIMMONS and LUCY F. DONALDSON
Abstract
Background: Cyclooxygenase-3 (Cox-3) is a recently identified cyclooxygenase which is inhibited by paracetamol-related drugs rather than traditional non-steroidal anti-inflammatory.
Aim of the Work: In this study the distribution of Cox-3 has been studied in the rat nervous system both in the central and peripheral nervous system.
Materials and Methods: Ten adult male Wistar rats weigh-ing 300-400g were killed by decapitation under brief anesthe-sia. Nervous system; brains, spinal cords, spinal ganglia and spinal nerves were removed and processed for immunohis-tochemistry using an antibody raised against Cox-3.
Results: Cox-3 was widely distributed in the rat nervous system. The expression appeared mainly neuronal. In the central nervous system, Cox-3 was localized in neurons in the brain and spinal cord. In the brain Cox-3 was highly expressed in cerebral cortex, hippocampus and cerebellum. In the peripheral nervous system Cox-3 was localized in neurons in the spinal ganglia and in the spinal nerves.
Conclusion: Cox-3 was widely distributed in the nervous system. Thus, this isoform could be contributing to the gen-eration of the physiological levels of prostaglandins normally needed for homeostatic regulation in the nervous system. Localisation of Cox-3 in areas associated with nociception and pain such as brain, spinal cord and spinal ganglia support the hypothesis that Cox-3 may be the central target of parac-etamol and other related centrally acting analgesics / anti-pyretics.