Acute tolerance to the analgesic action of nitrous oxide does not develop in rats.
The time course of nitrous oxide analgesia was studied in rats with a behavioral criterion, the tail-flick test to radiant heat. All rats were placed individually in a Plexiglas tube and exposed to either nitrous oxide, 75% in oxygen, or room air (control) for 2 hr. Analgesic potency was evaluated by prolongation of the time required to induce tail-flick. Although individual animals showed variability in the tail-flick time during exposure to nitrous oxide, no animal showed a tendency toward the development of tolerance, and a statistically significant sustained prolongation of tail-flick time was produced.
D000700:Analgesics; D000818:Animals; D004361:Drug Tolerance; D008297:Male; D013058:Mass Spectrometry; D009609:Nitrous Oxide / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D010100:Oxygen; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors
D000700:Analgesics; D009609:Nitrous Oxide; D010100:Oxygen