title: [Propofol-induced myocardial depression: possible role of atrial muscarinic cholinergic receptors].
abstract: OBJECTIVE
  To investigate the possible role of muscarinic cholinergic receptors (MCRs) in the depression of myocardial function induced by propofol, an intravenous anesthetic chemically unrelated to other drugs. Although adverse effects are rare, bradycardia has been reported and this can lead to cardiac arrest in some patients. The mechanism behind this effect is still unknown but a possible role for MCRs has been suggested.
  
  
  METHODS
  The interaction of propofol with human atrial MCRs was determined by means of inhibition tests using [3H] quinuclidinyl benzilate ([3H] QNB).
  
  
  RESULTS
  The displacement of [3H] QNB binding to human atrial MCRs by propofol was concentration dependent but the observed effect was not consistent with a model of simple competition between propofol and [3H] QNB.
  
  
  CONCLUSIONS
  Propofol appears to have the ability to modify the activity of human atrial MCRs and this effect may be related to its ability to induce bradycardia.
authors.affiliation: Unidad de Ensayos Clínicos, Unidad de Bioquímica Dr. José Antonio Moreno Yanes, Centro de Investigaciones Biomédicas, Decanato de Medicina, Universidad Centroccidental Lisandro Alvarado, Barquisimeto, Estado Lara, Venezuela. rafaeloyaguero@hotmail.com
authors.forename: R E
authors.initials: RE
authors.lastname: Aguero Peña
authors.forename: C
authors.initials: C
authors.lastname: Pascuzzo-Lima
authors.forename: A E
authors.initials: AE
authors.lastname: Granado Duque
authors.forename: R A
authors.initials: RA
authors.lastname: Bonfante-Cabarcas
mesh_terms: D018686:Anesthetics, Intravenous / Q000494:pharmacology / Q000633:toxicity*; D001919:Bradycardia / Q000139:chemically induced* / Q000503:physiopathology; D006325:Heart Atria / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008861:Microsomes / Q000187:drug effects; D015742:Propofol / Q000494:pharmacology / Q000633:toxicity*; D011813:Quinuclidinyl Benzilate / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000502:physiology
chemical_list: D018686:Anesthetics, Intravenous; D011976:Receptors, Muscarinic; C028484:quinuclidinyl benzilate receptor; D011813:Quinuclidinyl Benzilate; D015742:Propofol