DIRECT SPINAL EFFECT OF INTRATHECAL AND EXTRADURAL MIDAZOLAM ON VISCERAL NOXIOUS STIMULATION IN RABBITS
| Autor: | J. B. Madsen, F. Molke Jensen, M.E. Crawford, D.B. Toftdahl |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Flumazenil
medicine.medical_specialty Midazolam Injections Epidural Distension Injections Intramuscular Reflex medicine Noxious stimulus Animals Drug Interactions Injections Spinal Motor Neurons Dose-Response Relationship Drug business.industry Balloon catheter Spinal cord Surgery Viscera Anesthesiology and Pain Medicine medicine.anatomical_structure Nociception Spinal Cord Sensory Thresholds Anesthesia Female Rabbits business medicine.drug |
| Zdroj: | British Journal of Anaesthesia. 70:642-646 |
| ISSN: | 0007-0912 |
| DOI: | 10.1093/bja/70.6.642 |
| Popis: | SUMMARY We measured alterations in a noxious visceromotor reflex in rabbits subjected to intestinal distension, after i.m., extradural or intrathecal injection of midazolam or saline. Spinal catheters were inserted and tunnelled surgically and the animals allowed to recover for 2 weeks. A balloon catheter was placed in the distal part of the descending colon, in the awake rabbit. Intraluminalpressures were increased continuously by water instillation until a sudden withdrawal of the pelvis was observed. Pressure values at withdrawal threshold were recorded immediately before the injection and after 5, 15 and 30 min. Pain thresholds were unaltered after saline. Extradural midazolam 12.5-250 fig kg -1 produced a dose-dependent increase in the percent maximum possible effect ranging from 7% after the smallest dose to 80%. Similar dose-dependent effects were observed after intrathecal injection of midazolam 25-62.5 ng kg -1 . Extradural and intrathecal, but not i.v. injection of flumazenil 25 fig kg -1 (a benzo-diazepine receptor antagonist) reduced the anti-nociceptive effect of extradural and intrathecal midazolam to pretreatment levels. A segmental effect of intrathecal midazolam was demonstrated using transcutaneous electrical stimulation in the areas of the neck and the lower back. The effect of intrathecal midazolam 62.5 fig kg -1 was restricted to the lumbar region, demonstrating a selective action on the spinal cord. Thus extradural and intrathecal midazolam produced a dose-dependent effect on the reflex response to visceral distension in rabbits. This effect is caused by a direct spinal action on benzodiazepine receptors in the spinal cord. (Br. J. Anaesth. 1993; 70: 642–646) |
| Databáze: | OpenAIRE |
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