Spinal cord effects of drugs used in anaesthesia.
1. Measurement of nociceptive thresholds at two skin sites in rats with chronic intrathecal catheters has allowed study of drug actions demonstrated to be at spinal level. 2. Using this preparation we have demonstrated segmental antinociceptive effects following intrathecal administration of agonists selective for benzodiazepine receptors, mu, kappa and delta opioid receptors, 5-hydroxytryptamine (5-HT) receptors and alpha adrenoceptors. 3. Such effects were dose related and were suppressed by appropriate selective antagonists. 4. Antagonist dose-response curves have been constructed for suppression of antinociceptive effects of various agonists. This has revealed complex interactions between spinal systems; for example midazolam produces its actions by activating an opioid system involving delta receptors.
Goodchild
C S
CS
Department of Anaesthesia, University of Leeds, England.
Gent
J P
JP
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D009619:Nociceptors / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D013116:Spinal Cord / Q000187:drug effects*
D000777:Anesthetics