title: [Changes in pain sensitivity under increased atmospheric pressure].
abstract: It has been established that augmentation of air pressure from 0.1 to 1.1 MPa (with 0.1 MPa intervals) was accompanied in rats with the development of progressive analgesia which was measured according to the threshold of vocalization in the test of electrical stimulation of the tail. The highest analgesic response arose at 0.7-1.1 MPa. All the animals might be divided into two groups: group 1-72% of the animals with a 200% increase of the threshold, group 2--animals with such an increase by 15%. The augmentation of the pressure of heliox (79.1% of helium, 20.9% of oxygen) also caused analgesia, but not so strong. In patients pain thresholds to the mechanical nociceptive stimulation also increased by about 43-67% and 95-100% under the influence of increased air pressure of 0.4 and 0.7 MPa, respectively. In group 1 patients (67%) pain threshold increased by 50-100%, in group 2 by 15-25%. Pretreatment with naloxone (1 mg/kg), atropine (1 mg/kg), yohimbine (1 mg/kg), parachloramphetamine (5 mg/kg) and prasosin (1 mg/kg) decreased hyperbaric analgesia in rats by 41-56, 41-56, 17-19, 17-19%, respectively. The role of increased partial pressure of nitrogen in hyperbaric analgesia and possible neurochemical mechanisms of its realization are discussed.
authors: Iu D
authors: IuD
authors: Ignatov
authors: A A
authors: AA
authors: Miasnikov
authors: Iu N
authors: IuN
authors: Vasil'ev
authors: N N
authors: NN
authors: Vinnichuk
mesh_terms: D000328:Adult; D000698:Analgesia; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001274:Atmospheric Pressure; D004558:Electric Stimulation / Q000379:methods; D006371:Helium / Q000494:pharmacology; D006801:Humans; D008297:Male; D010100:Oxygen / Q000494:pharmacology; D010147:Pain Measurement / Q000295:instrumentation; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013997:Time Factors
chemical_list: D006371:Helium; C038949:heliox; D010100:Oxygen
vernacular_title: Izmenenie bolevoĭ chuvstvitel'nosti pri povyshennom atmosfernom davlenii.