Decrease of beta-endorphin in the brain of rats following nitrous oxide withdrawal.
beta-Endorphin levels in the whole rat brain were not changed during acute (25 min) or chronic (48 h) exposure of rats to N2O. However, a significant decrease of beta-endorphin was found in the whole brain, brain stem and subcortex during the withdrawal from chronic exposure to N2O. It has been suggested that decrease of beta-endorphin levels during N2O withdrawal could be ascribed to unspecific stress accompanying drug withdrawal. Decrease of central beta-endorphin during N2O withdrawal might have a significant modulatory effect on transmitter balance, neuronal excitability and corresponding withdrawal behaviour. Furthermore, the decrease of beta-endorphin levels in the whole brain during N2O withdrawal might contribute to the postanaesthesia N2O-excitatory syndrome in humans. This might explain the known therapeutic effect of the opioid drug, meperidine on the excitatory N2O withdrawal phenomena during recovery from N2O anaesthesia in man.
Dzoljic
M R
MR
Department of Pharmacology, Faculty of Medicine and Health Sciences, Erasmus University, Rotterdam, The Netherlands.
Haffmans
J
J
Rupreht
J
J
Adolfs
M J
MJ
Dzoljic
M M
MM
Cappendijk
S L
SL
D000818:Animals; D001273:Atmosphere Exposure Chambers; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009609:Nitrous Oxide / Q000009:adverse effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D001615:beta-Endorphin / Q000378:metabolism*
D001615:beta-Endorphin; D009609:Nitrous Oxide