[Propofol-induced myocardial depression: possible role of atrial muscarinic cholinergic receptors].
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.
Aguero Peña
R E
RE
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
Pascuzzo-Lima
C
C
Granado Duque
A E
AE
Bonfante-Cabarcas
R A
RA
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
D018686:Anesthetics, Intravenous; D011976:Receptors, Muscarinic; C028484:quinuclidinyl benzilate receptor; D011813:Quinuclidinyl Benzilate; D015742:Propofol