Antinociceptive role of 5-HT1A receptors in rat spinal cord
| Autor: | C S Goodchild, Raymond Nadeson |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Agonist
Male Hot Temperature medicine.drug_class Pain Pharmacology medicine Noxious stimulus Reaction Time Animals Rats Wistar Receptor Pain Measurement Dose-Response Relationship Drug business.industry Antagonist Spinal cord Electric Stimulation Rats Serotonin Receptor Agonists Anesthesiology and Pain Medicine medicine.anatomical_structure Nociception Mechanism of action Spinal Cord Receptors Serotonin Serotonin medicine.symptom business Neuroscience Receptors Serotonin 5-HT1 |
| Zdroj: | British journal of anaesthesia. 88(5) |
| ISSN: | 0007-0912 |
| Popis: | Background Intrathecal administration of 5-hydroxytryptamine (5-HT) is antinociceptive to noxious heat and electrical stimuli. The contributions of different receptor subtypes to the antinociceptive effects of 5-HT are controversial. The main reasons for this are the poor receptor subtype selectivity of some agonist drugs and the difficulty of restricting drug action to the spinal cord in some experimental paradigms. This study investigated the roles of different 5-HT receptor subtypes involved in the spinal cord control of the nociception produced by these two nociceptive testing paradigms. Methods Tail-flick latency and electric current threshold for nociception were measured in an acute pain model that allowed the study of the antinociceptive effects of intrathecally administered drugs that were due to actions of these drugs at spinal cord receptors. Experiments were performed in male Wistar rats with chronically implanted lumbar subarachnoid catheters. Dose–response curves for spinally mediated antinociceptive effects of agonists selective for 5-HT receptor subtypes were constructed. Results The 5-HT 1 agonist 1-(3-chlorophenyl)-piperazine dihydrochloride caused a dose-dependent antinociceptive effect, measured by both nociceptive tests. However, 8-hydroxy-DPAT (selective 5-HT 1A agonist) produced antinociception assessed by electric current but not tail flick. A 5-HT 1A -selective antagonist, 4-[3-(benzotriazol-1-yl)propyl]-1-(2-methoxyphenyl)-piperazine, reversed the antinociception in the electrical test produced by both of these agonists but the tail-flick latency effects after intrathecal 1-(3-chlorophenyl)-piperazine were not suppressed by this antagonist. Conclusions We conclude that 5-HT 1A receptors in the spinal cord are involved in the nociceptive mechanisms assessed by noxious electrical stimuli. Other 5-HT 1 receptors (non 5-HT 1A receptors) are involved in the spinally mediated antinociception assessed by thermal noxious stimuli. |
| Databáze: | OpenAIRE |
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