Differential effects of intrathecal midazolam on morphine-induced antinociception in the rat: role of spinal opioid receptors.
Anesth Analg
; 73(2): 124-31, 1991 Aug.
Article
en En
| MEDLINE
| ID: mdl-1649558
The antinociceptive effects of an intrathecally administered benzodiazepine agonist midazolam, alone and in combination with morphine, were examined in the rat by using the tail-flick test. The duration of antinociceptive effect produced by midazolam was significantly less (P less than 0.05) than that produced by morphine. Low doses of midazolam (10 micrograms) and morphine (10 micrograms) produced a synergistic effect in prolonging antinociceptive effect. However, at higher doses (20 or 30 micrograms), these drugs reduced the extent of antinociception produced by each other. Naloxone administration prevented antinociception produced by these drugs, indicating interactions between midazolam and opioid receptors. Midazolam had dual effects on the binding of opioid ligands to the spinal opioid receptors. At low dose, it potentiated the displacement of [3H]naloxone by morphine. At higher doses, midazolam inhibited the binding of opioid ligands to their spinal receptors in the following order: kappa greater than delta greater than mu. These results indicate that differential antinociceptive effects of midazolam on morphine-induced antinociception involve interaction of this benzodiazepine with spinal opioid receptors.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Dolor
/
Médula Espinal
/
Midazolam
/
Receptores Opioides
/
Morfina
/
Naloxona
Límite:
Animals
Idioma:
En
Revista:
Anesth Analg
Año:
1991
Tipo del documento:
Article
Pais de publicación:
Estados Unidos