title: Excitation-contraction uncoupling during ischemia in the blood perfused dog heart.
abstract: The bioluminescent of Ca(2+)-indicator, aequorin, was loaded into the left ventricular apex of blood-perfused hearts from 13 dogs for simultaneous recording of left ventricular pressure and intracellular calcium levels. During a 2 minute period of ischemia, systolic and diastolic pressures significantly decreased. In contrast, these pressure changes were associated with an increase in both systolic and diastolic calcium reaching a maximum diastolic value of 0.59 microM and a systolic value of 1.11 microM. This apparent dissociation between pressure and [Ca2+]i supports the hypothesis that changes in myofilament Ca2+ responsiveness are of major importance in modulating contractility during ischemia in large mammalian hearts.
authors.affiliation: Charles A. Dana Research Institute, Boston, MA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Levine
authors.forename: K
authors.initials: K
authors.lastname: Harada
authors.forename: A J
authors.initials: AJ
authors.lastname: Meuse
authors.forename: J
authors.initials: J
authors.lastname: Watanabe
authors.forename: J
authors.initials: J
authors.lastname: Breall
authors.forename: J P
authors.initials: JP
authors.lastname: Carrozza
authors.forename: L
authors.initials: L
authors.lastname: Bentivegna
authors.forename: A
authors.initials: A
authors.lastname: Franklin
authors.forename: R G
authors.initials: RG
authors.lastname: Johnson
authors.forename: W
authors.initials: W
authors.lastname: Grossman
mesh_terms: D000331:Aequorin; D000818:Animals; D001794:Blood Pressure; D002118:Calcium / Q000378:metabolism*; D003327:Coronary Disease / Q000503:physiopathology*; D004285:Dogs; D006321:Heart / Q000502:physiology* / Q000503:physiopathology; D066298:In Vitro Techniques; D007700:Kinetics; D009200:Myocardial Contraction; D010477:Perfusion
chemical_list: D000331:Aequorin; D002118:Calcium