Mechanism of differential cardiovascular response to propofol in Dahl salt-sensitive, Brown Norway, and chromosome 13-substituted consomic rat strains: role of large conductance Ca2+ and voltage-activated potassium channels. J Pharmacol Exp Ther 2009 Sep;330(3):727-35
Date
06/23/2009Pubmed ID
19541907Pubmed Central ID
PMC2729794DOI
10.1124/jpet.109.154104Scopus ID
2-s2.0-70349106455 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
Cardiovascular sensitivity to general anesthetics is highly variable among individuals in both human and animal models, but little is known about the genetic determinants of drug response to anesthetics. Recently, we reported that propofol (2,6-diisopropylphenol) causes circulatory instability in Dahl salt-sensitive SS/JRHsdMcwi (SS) rats but not in Brown Norway BN/NHsdMcwi (BN) rats and that these effects are related to genes on chromosome 13. Based on the hypothesis that propofol does target mesenteric circulation, we investigated propofol modulation of mesenteric arterial smooth muscle cells (MASMC) in SS and BN rats. The role of chromosome 13 was tested using SS-13(BN)/Mcwi and BN-13(SS)/Mcwi consomic strains with chromosome 13 substitution. Propofol (5 microM) produced a greater in situ hyperpolarization of MASMC membrane potential in SS than BN rats, and this effect was abrogated by iberiotoxin, a voltage-activated potassium (BK) channel blocker. In inside-out patches, the BK channel number, P(o), and apparent Ca(2+) sensitivity, and propofol sensitivity all were significantly greater in MASMC of SS rats. The density of whole-cell BK current was increased by propofol more in SS than BN myocytes. Immunolabeling confirmed higher expression of BK alpha subunit in MASMC of SS rats. Furthermore, the hyperpolarization produced by propofol, the BK channel properties, and propofol sensitivity were modified in MASMC of SS-13(BN)/Mcwi and BN-13(SS)/Mcwi strains toward the values observed in the background SS and BN strains. We conclude that differential function and expression of BK channels, resulting from genetic variation within chromosome 13, contribute to the enhanced propofol sensitivity in SS and BN-13(SS)/Mcwi versus BN and SS-13(BN)/Mcwi strains.
Author List
Stadnicka A, Contney SJ, Moreno C, Weihrauch D, Bosnjak ZJ, Roman RJ, Stekiel TAAuthor
Dorothee Weihrauch DVM, PhD Research Scientist II in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsAnimals, Genetically Modified
Benzimidazoles
Chromosomes
Hemodynamics
Humans
Hypnotics and Sedatives
In Vitro Techniques
Large-Conductance Calcium-Activated Potassium Channels
Membrane Potentials
Myocytes, Smooth Muscle
Patch-Clamp Techniques
Peptides
Potassium Channels, Voltage-Gated
Propofol
Rats
Rats, Inbred BN
Rats, Inbred Dahl
Species Specificity
Splanchnic Circulation
Vascular Resistance