[A comparative evaluation of the chronobiological organization of the pain-relieving action of analgesics].
The spectral analysis of over 50-hour series of observations (tail flick) has revealed two ultradian periodicities of rat pain sensitivity with 8- and 12-hour duration and the circadian one. The minimum sensitivity was observed in the first half of the light phase. Morphine (5 mg/kg i.p.) did not change the spectrum of rhythms, but inverted the phase of a circadian constituent--it was most effective in the middle of the dark phase. Naloxone (1 mg/kg) significantly changed the spectrum of ultradian rhythms, but did not alter the length and phase of circadian periodicity. After moradol (1 mg/kg) administration it could decrease and alter the spectrum of periodicities with the most prominent infradian rhythm. On the contrary, metamizole (50 mg/kg) injections did not interfere the rhythmic pattern of pain sensitivity. Thus, narcotic analgesics have specific effects on the chronological organization of pain sensitivity rather than non-narcotic ones do.
Kubynin
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Ignatov
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D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002909:Chronobiology Phenomena / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D013623:Tail; D013997:Time Factors
D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone