title: Central beta-endorphin release and recovery after exposure to nitrous oxide in rats.
abstract: To explore the hypothesis that nitrous oxide stimulates the beta-endorphin system in vivo, rats were exposed to nitrous oxide/oxygen at variable concentrations for one hour. beta-Endorphin concentration at sites along the neuraxis functionally involved with analgesia was elevated in nitrous oxide-exposed animals. The increase in beta-endorphin concentration was statistically significant at nitrous oxide concentrations of 60 and 80%. This elevation of beta-endorphin levels depended on the concentration of nitrous oxide delivered rather than on the duration of exposure. With cessation of nitrous oxide anesthesia, beta-endorphin concentration returned to control levels within 30 minutes.
mesh_terms: D000818:Animals; D004027:Diencephalon / Q000032:analysis / Q000378:metabolism*; D004723:Endorphins / Q000032:analysis / Q000378:metabolism*; D007031:Hypothalamus / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008636:Mesencephalon / Q000378:metabolism; D009609:Nitrous Oxide / Q000008:administration & dosage / Q000494:pharmacology*; D010100:Oxygen; D010487:Periaqueductal Gray / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D001615:beta-Endorphin; D009609:Nitrous Oxide; D010100:Oxygen