title: Effects of lidocaine on ischemic myocardial metabolism assessed by 31P-NMR in the isolated perfused rat heart.
abstract: Using an isolated perfused rat heart preparation, the protective effects of lidocaine and diltiazem on ischemic derangements of myocardial energy metabolism were studied with 31P-nuclear magnetic resonance spectroscopy. The hearts were perfused with a solution containing lidocaine (4.27 x 10(-5), 12.80 x 10(-5) M) or diltiazem (2.22 x 10(-7), 2.22 x 10(-6) M) for 15 min prior to the induction of global ischemia. The decrease in myocardial oxygen consumption rate, assessed as the product of heart rate and left ventricular systolic pressure (HR x LVP), was greater in diltiazem-treated than in lidocaine-treated hearts. Diltiazem and lidocaine significantly retarded the fall in myocardial pH during ischemia and improved ATP recovery after reperfusion. There was a good correlation between suppression of HR x LVP observed before induction of ischemia and decreased drop in pH during the early phase of ischemia in the diltiazem-treated groups (r = -0.78, p less than 0.01), but not in the lidocaine-treated groups. These results indicate that the beneficial effects of diltiazem on the ischemic myocardium are due primarily to the cardio-depressant effects. The beneficial effects of lidocaine cannot, however, be explained solely on the basis of the depression of oxygen consumption.
authors.affiliation: Department of Pharmacology, Niigata University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Ishibashi
authors.forename: M
authors.initials: M
authors.lastname: Nakazawa
authors.forename: M
authors.initials: M
authors.lastname: Yamazoe
authors.forename: T
authors.initials: T
authors.lastname: Izumi
authors.forename: A
authors.initials: A
authors.lastname: Shibata
authors.forename: S
authors.initials: S
authors.lastname: Imai
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D004110:Diltiazem / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010758:Phosphorus; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D010758:Phosphorus; D008012:Lidocaine; D004110:Diltiazem