Effects of halothane on transmembrane potentials, Ca2+ transients, and papillary muscle tension in the cat. Am J Physiol 1986 Aug;251(2 Pt 2):H374-81
Date
08/01/1986Pubmed ID
3740291DOI
10.1152/ajpheart.1986.251.2.H374Scopus ID
2-s2.0-0022475722 (requires institutional sign-in at Scopus site) 37 CitationsAbstract
The effects of halothane on cat papillary muscle were studied in vitro at different pacing rates (60, 75, 100, and 150 beats/min). Simultaneous measurements of transmembrane potentials, intracellular Ca2+ transients, and isometric tension were made before and after introduction of 1 and 2 minimal alveolar concentration halothane. Anesthetic concentrations in the superfusion bath were measured using a gas chromatography procedure. The Ca2+-sensitive photoprotein, aequorin, was microinjected into papillary muscle cells. Aequorin light emission is a function of free intracellular [Ca2+] [( Ca2+]i). The most prominent effects of halothane were a dose-dependent decrease in the contractile force and a decrease in [Ca2+]i, at all pacing rates. The negative inotropic effect of halothane was associated with only small changes in the papillary muscle action potential duration. Increasing the extracellular [Ca2+] produced an increase in [Ca2+]i and counteracted the negative inotropic effects of halothane. Addition of the Ca2+ channel blocker, verapamil, and halothane, produced an additive decrease in [Ca2+]i compared with the control.
Author List
Bosnjak ZJ, Kampine JPMESH terms used to index this publication - Major topics in bold
Action PotentialsAequorin
Animals
Calcium
Cats
Halothane
Heart Rate
Membrane Potentials
Myocardial Contraction
Osmolar Concentration
Papillary Muscles
Regression Analysis
Verapamil
