Open AccessBinding of Fentanyl and Pethidine to Muscarinic Receptors in Rat Brain
Author(s) -
Olav Hustveit
Publication year - 1994
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.64.57
Subject(s) - pethidine , fentanyl , muscarinic acetylcholine receptor , alfentanil , opioid , morphine , pharmacology , (+) naloxone , receptor , chemistry , opioid receptor , anesthesia , medicine , analgesic
Symptoms similar to the central anticholinergic syndrome are often seen after high dose fentanyl anesthesia. Therefore, the binding of fentanyl, alfentanil, pethidine and morphine to opioid and muscarinic receptors was investigated in rat brain homogenate with [3H]naloxone and [3H]QNB as the radioligands, respectively. Both pethidine and fentanyl inhibited [3H]QNB binding with Ki values in the micromolar range. Alfentanil and morphine had no affinity for muscarinic receptors. The ratio of the Ki values for muscarinic receptors versus opioid receptors was 2.5 for pethidine and 88 for fentanyl. It is concluded that binding of fentanyl to muscarinic receptors is likely to occur during high-dose fentanyl anesthesia.