Abstract | BACKGROUND: Administration of opioid receptor agonists is followed by paradoxical sensory hypersensitivity. This hypersensitivity has been suggested to contribute to the antinociceptive tolerance observed with opioids. The authors hypothesized that alpha 2-adrenoreceptor agonists, which also produce antinociceptive tolerance, would produce sensory hypersensitivity. METHODS: alpha 2-Adrenoreceptor agonists were administered to male Sprague-Dawley rats as a single subcutaneous injection, a continuous subcutaneous infusion, a single intrathecal injection, or a continuous intrathecal infusion. Thermal sensitivity was determined using latency to withdrawal of the hind paw from radiant heat. Tactile sensitivity was determined using withdrawal threshold to von Frey filaments. Spinal dynorphin content was measured by enzyme immunoassay. RESULTS: CONCLUSIONS:
|
Authors | Aline Quartilho, Heriberto P Mata, Mohab M Ibrahim, Todd W Vanderah, Michael H Ossipov, Josephine Lai, Frank Porreca, T Philip Malan Jr |
Journal | Anesthesiology
(Anesthesiology)
Vol. 100
Issue 6
Pg. 1538-44
(Jun 2004)
ISSN: 0003-3022 [Print] United States |
PMID | 15166576
(Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)
|
Chemical References |
- Adrenergic alpha-2 Receptor Agonists
- Adrenergic alpha-Agonists
- Receptors, Adrenergic, alpha-2
- Dizocilpine Maleate
- Clonidine
|
Topics |
- Adrenergic alpha-2 Receptor Agonists
- Adrenergic alpha-Agonists
(pharmacology)
- Animals
- Clonidine
(pharmacology)
- Dizocilpine Maleate
(pharmacology)
- Drug Hypersensitivity
(diagnosis, physiopathology)
- Male
- Pain Measurement
(methods)
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha-2
(metabolism)
|