Myocardial oxygen consumption and the left ventricular pressure-volume area in normal and hypertrophic canine hearts.

The effect of nicotine on adenosine release, oxygen consumption, and contractility was investigated in perfused rat hearts. Continuous infusion of nicotine into the perfusing physiological saline (PS) elicited a propranolol (10(-6) M) sensitive transient elevation of developed left ventricular pressure (LVP) and maximum rates of left ventricular pressure development and relaxation (+/- dP/dtmax) within 20 s, which subsequently declined to maintained elevated plateau levels by 1 min. The continuous infusions of nicotine to achieve PS concentrations of 5 X 10(-4), 1 X 10(-4), or 5 X 10(-5) M, respectively resulted in significant increases in the mean plateau levels of LVP (33.4, 10.1, or 6.3%), +dP/dtmax (26.3, 10.8, or 6.9%) and-dP/dtmax (35.0, 11.9, or 9.0%) at 1 min. The inclusion of propranolol (10(-6) M) with or without atropine (10(-6) M) did not alter these maintained plateau responses to nicotine. During the plateau phase of the contractile response oxygen consumption of the hearts was significantly elevated by 36, 19, or 11%, and mean levels for adenosine in the coronary effluent rose by 261, 76, or 74% in response to 5 X 10(-4), 1 X 10(-4), or 5 X 10(-5) M nicotine, respectively. Nicotine did not influence [14C]adenosine uptake by the hearts. These results suggest that nicotine is capable of 1) augmenting cardiac contractility and oxygen consumption independent of beta-adrenergic or muscarinic influence, and 2) elevating the appearance of adenosine in the coronary circulation presumably by enhancing myocardial production of the nucleoside.

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Effects of Intraduodenal Administration of "Kyushin," a Senso (Toad Venom)-Containing Drug, on Systemic Hemodynamics, CardiacFunction and Myocardial Oxygen Consumption in Anesthetized Dogs

The American Journal of Chinese Medicine ◽

10.1142/s0192415x93000030 ◽

1993 ◽

Vol 21 (01) ◽

pp. 7-16 ◽

Cited By ~ 2

Author(s):

Matao Sakanashi ◽

Katsuhiko Noguchi ◽

Takao Chibana ◽

Yoshihiko Ojiri ◽

Masamichi Shoji

Keyword(s):

Oxygen Consumption ◽

Myocardial Oxygen Consumption ◽

Diastolic Pressure ◽

Left Ventricular Pressure ◽

Cardiovascular Effects ◽

Left Ventricular ◽

Toad Venom ◽

The Relationship ◽

Cardiotonic Effect ◽

Intraduodenal Administration

The effects of "Kyushin" (KY), a Senso (toad venom)-containing drug, on the cardiovascular system were examined by intraduodenal administration of KY in anesthetized open-chest dogs. KY (3 or 10 mg/kg) dose-dependently increased the peak positive first derivative of left ventricular pressure ((+)LVdP/dt) and mean aortic pressure, and decreased the left ventricular end-diastolic pressure (LVEDP). Myocardial oxygen consumption (MVO2) and heart rate (HR) were not significantly influenced by KY. KY produced a cardiotonic effect without any increase in MVO2, because the increase in MVO2 due to the cardiotonic effect of KY may have been cancelled by a decrease in MVO2 due to reduction of preload and the lack of increase in HR. In order to clarify the relationship between the cardiovascular effects of KY and the drug concentration in plasma, the concentration of anti-bufalin IgG reactive substance (BRS) in plasma was measured by enzyme immunoassay. The maximum BRS concentrations 20 min after administration of 3 and 10 mg/kg KY were dose-dependent. From the relationship between changes in (+)LVdP/dt and changes in BRS concentration after administration of KY, it is inferred that the effective concentration of BRS in plasma at which KY produces a cardiotonic effect in dogs is approximately 2-3 ng/ml.

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Effect of hyperosmotic mannitol on myocardial oxygen consumption

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1977.233.4.h444 ◽

1977 ◽

Vol 233 (4) ◽

pp. H444-H450

Author(s):

G. J. Vlahakes ◽

W. J. Powell

Keyword(s):

Oxygen Consumption ◽

Myocardial Oxygen Consumption ◽

Diastolic Pressure ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Coronary Perfusion ◽

Tension Time ◽

Anesthetized Dogs ◽

Myocardial Efficiency ◽

Experimental Myocardial Ischemia

Hyperosmotic mannitol produces salutary hemodynamic and histologic effects during experimental myocardial ischemia. However, the administration of hyperosmotic mannitol is associated with a positive inotropic influence. Positive inotropic interventions, which increase myocardial oxygen consumption (MVO2), also tend to increase the extent of ischemic myocardial injury. Thus, the purpose of this study was to determine the effect of mannitol on MVO2. Anesthetized dogs on right-heart bypass under conditions of controlled hemodynamics were studied. Both coronary arteries were perfused; mannitol was infused via the coronary perfusion cannulas to produce a 35 mosmol increase in osmolality. Heart rate was maintained constant. Cardiac output was held constant or deliberately increased so that left ventricular end-diastolic pressure and tension-time index, two other hemodynamic correlates of MVO2, remained constant or increased. MVO2 significantly decreased under conditions of decreased myocardial perfusion (P less than 0.025). This was in spite of a significant increase (P less than 0.001) in the peak rate of rise of left ventricular pressure (LV dP/dt), a hemodynamic correlate of MVO2. Thus, hyperosmotic mannitol under conditions of reduced coronary perfusion increases myocardial efficiency.

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Endothelin Receptor Blockade Improves Left Ventricular Pressure-Volume Relationships Without Altering the Hypertrophic Response During Congestive Heart Failure in Rats

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(97)84967-4 ◽

1998 ◽

Vol 31 (2) ◽

pp. 289A

Author(s):

E Øie

Keyword(s):

Heart Failure ◽

Congestive Heart Failure ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Receptor Blockade ◽

Endothelin Receptor ◽

Hypertrophic Response

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Clinical and Experimental Analysis of 201Thallium Uptake of the Heart

Nuklearmedizin ◽

10.1055/s-0037-1620682 ◽

1978 ◽

Vol 17 (04) ◽

pp. 142-148

Author(s):

U. Büll ◽

S. Bürger ◽

B. E. Strauer

Keyword(s):

Oxygen Consumption ◽

Left Ventricle ◽

Muscle Mass ◽

Myocardial Oxygen Consumption ◽

Animal Experiments ◽

Left Ventricular ◽

Left Ventricular Wall ◽

Ventricular Wall ◽

Flow Measurements ◽

Myocardial Flow

Studies were carried out in order to determine the factors influencing myocardial 201T1 uptake. A total of 158 patients was examined with regard to both 201T1 uptake and the assessment of left ventricular and coronary function (e. g. quantitative ventriculography, coronary arteriography, coronary blood flow measurements). Moreover, 42 animal experiments (closed chest cat) were performed. The results demonstrate that:1) 201T1 uptake in the normal and hypertrophied human heart is linearly correlated with the muscle mass of the left ventricle (LVMM);2) 201T1 uptake is enhanced in the inner (subendocardial) layer and is decreased in the outer (subepicardial) layer of the left ventricular wall. The 201T1 uptake of the right ventricle is 40% lower in comparison to the left ventricle;3) the basic correlation between 201T1 uptake and LVMM is influenced by alterations of both myocardial flow and myocardial oxygen consumption; and4) inotropic interventions (isoproterenol, calcium, norepinephrine) as well as coronary dilatation (dipyridamole) may considerably augment 201T1 uptake in accordance with changes in myocardial oxygen consumption and/or myocardial flow.It is concluded that myocardial 201T1 uptake is determined by multiple factors. The major determinants have been shown to include (i) muscle mass, (ii) myocardial flow and (iii) myocardial oxygen consumption. The clinical data obtained from patient groups with normal ventricular function, with coronary artery disease, with left ventricular wall motion abnormalities and with different degree of left ventricular hypertrophy are correlated with quantitated myocardial 201T1 uptake.

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