Prolonged antinociception following carbon dioxide anesthesia in the laboratory rat
| Autor: | Julia W. Nalwalk, August H. Battles, Scott A. Mischler, Mathew Alexander, John Raucci, Lindsay B. Hough |
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| Rok vydání: | 1994 |
| Předmět: |
Male
Hypophysectomy Hot Temperature medicine.medical_treatment Naltrexone Rats Sprague-Dawley Physical Stimulation medicine Reaction Time Animals Anesthesia Molecular Biology Endogenous opioid Pain Measurement Inhalation Chemistry General Neuroscience Antagonist Nociceptors Carbon Dioxide Laboratory rat Rats Nociception Neurology (clinical) Opiate Developmental Biology medicine.drug |
| Zdroj: | Brain research. 640(1-2) |
| ISSN: | 0006-8993 |
| Popis: | In the laboratory rat, inhalation (30 s) of high (70%) CO2 concentrations resulted in short-term (1-3 min) anesthesia, followed by a prolonged (up to 60 min) mild antinociception. Exposure to 100% CO2 resulted in significant thermal (hot-plate, 52 degrees, and tail-flick) and mechanical (tail-pinch, 886 g force) antinociception. Control animals, placed in the same chamber filled with air, showed no such effects. Rats exposed to 70% CO2 exhibited effects on the hot plate comparable to those seen after inhalation of 100% CO2, indicating that the response is not due to CO2-induced hypoxia. Additionally, recovery from halothane-induced anesthesia of comparable duration did not result in antinociception, confirming that anesthesia alone is not sufficient to produce the effect. Pretreatment with the opiate antagonist naltrexone (0.1-10 mg/kg i.p.) did not diminish the CO2-induced antinociception, suggesting that endogenous opioids are not obligatory in the mechanism of this response. Furthermore, hypophysectomy abolished hot-plate antinociception in animals exposed to 100% CO2 while sham-treated controls exhibited a pattern of hot-plate responses similar to that reported above. Taken together, these findings show that: (1) recovery from CO2-induced anesthesia results in a prolonged mild antinociception, detectable with thermal and mechanical nociceptive tests; and (2) this response may represent a novel from of environmentally induced antinociception, mediated by a non-opiate hormonal substance. |
| Databáze: | OpenAIRE |
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