title: [The anodyne action of narcotic analgesics and clofelin under increased atmospheric pressure].
abstract: Rat experiments have revealed that gradual increases in atmospheric pressure up to 1.1 MPa progressively alters the vocalization threshold in electrical stimulation of the tail root. Substitution of air for heliox (79.1% helium and 20.9% oxygen) leads to attenuation of the analgesic effect of hyperbarism. It is postulated that hyperbaric analgesia is due mainly to the elevated partial pressure of nitrogen. Morphine and promedol in doses of 2.5 mg/kg and clofeline in a dose of 0.1 mg failed to change analgesic effects when atmospheric pressure was increased up to 0.7 and 1.1 MPa. The analgesic effect of morphine and promedol in doses of 5 mg/kg and buprenorphine in a dose of 0.035 mg/kg under similar conditions increased during the whole period of isopression, while that of clofeline in a dose of 0.5 mg/kg increased only in the first few minutes of isopression. The analgesic action of morphoeceptine in a dose of 5 mg/kg decreased during isopression. The possible mechanisms of hyperbaric analgesia and the specific features of the analgesic action of different drugs at elevated atmospheric pressure are discussed.
authors.forename: Iu D
authors.initials: IuD
authors.lastname: Ignatov
authors.forename: A A
authors.initials: AA
authors.lastname: Miasnikov
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001274:Atmospheric Pressure; D003000:Clonidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D008297:Male; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D012149:Restraint, Physical; D013623:Tail; D014828:Vocalization, Animal / Q000187:drug effects
chemical_list: D000701:Analgesics, Opioid; D003000:Clonidine
vernacular_title: Boleutoliaiushchee deĭstvie narkoticheskikh anal'getikov i klofelina pri povyshennom atmosfernom davlenii.