scholarly journals The interrelationship of weight change and coronary flow in the isolated perfused rabbit heart

1959 ◽  
Vol 148 (2) ◽  
pp. 403-416 ◽  
Author(s):  
J. Stubbs ◽  
W. F. Widdas
1964 ◽  
Vol 47 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Fernando Vargas ◽  
John A. Johnson

Isolated perfused rabbit hearts have been used to determine the reflection coefficients, σ, of the heart capillaries to certain lipoid-insoluble substances. This was done by initially perfusing the heart with a Ringer solution containing no test molecule and then suddenly switching to a solution which differed from the original only by containing a small amount of test substance. This produced a loss of weight of the heart which was continuously recorded as a function of time. Taking the "zero" time rate of weight change and using an equation given by Kedem and Katchalsky reflection coefficients for urea, sucrose, raffinose, and inulin were obtained. These turned out to be 0.1, 0.3, 0.38, and 0.69 respectively. Using the approach of Durbin and Solomon equivalent pore radii were estimated to be about 35 Angstroms.


1991 ◽  
Vol 21 (1) ◽  
pp. 144-150 ◽  
Author(s):  
John C. Chatham ◽  
Stacey Ackerman ◽  
Stephen J. Blackband

1986 ◽  
Vol 250 (6) ◽  
pp. H998-H1007 ◽  
Author(s):  
C. L. Gibbs ◽  
G. Kotsanas

Basal metabolism has been measured in isolated whole hearts from rabbits and compared with myothermic and polarographic measurements on isolated papillary muscles. Hearts were perfused at constant pressure (Langendorff method) using a modified Krebs-Henseleit solution (KH) with glucose as substrate. Higher levels of basal O2 consumption (MVO2) and coronary flow (CF) were observed when arrest was induced by calcium depletion (low Ca; 0.1 mM CaCl2, 10.0 mM KCl) rather than by potassium excess (high K; 30.0 mM KCl). The metabolic rate of high K arrested hearts was close to earlier myothermic estimates (J. Mol. Cell. Cardiol. 16: 953-962, 1984); polarographic values, however, were about twofold higher, and somewhat higher than the value obtained in low Ca arrested hearts. The addition of erythrocytes, albumin, or dextran significantly reduced CF but did not substantially alter basal MVO2. Basal metabolic rate was substrate- and O2 tension-dependent, and under all experimental conditions there was linear relationship between MVO2 and CF. Extrapolations to zero flow showed that the basal MVO2 values so obtained were similar in low Ca or high K and were not altered by the presence of erythrocytes. Our results show that there are several factors regulating basal metabolism.


1991 ◽  
Vol 261 (5) ◽  
pp. H1630-H1635
Author(s):  
H. Yaku ◽  
B. K. Slinker ◽  
E. S. Myhre ◽  
M. W. Watkins ◽  
M. M. Lewinter

We evaluated the mechanical and energetic stability of the isolated rabbit heart perfused with a suspension of bovine red cells in Krebs-Henseleit buffer in terms of the pressure-volume area (PVA) concept. PVA, the area surrounded by the end-systolic and end-diastolic pressure-volume (P-V) relations and the systolic P-V trajectory of the P-V diagram, represents the total mechanical energy generated by each cardiac contraction. Myocardial O2 consumption (VO2) per beat has been reported to be highly linearly correlated with PVA. We used the slope and VO2-axis intercept of the VO2-PVA relation as energetic parameters and the maximum P-V ratio (Emax) as a contractility index of the left ventricle (LV) and compared them every 30 min for 120 min. Emax, the slope, and VO2 intercept of the VO2-PVA relation did not change significantly over 120 min compared with their control values [7.3 +/- 2.9 mmHg.ml-1.100 g LV, (1.67 +/- 0.40) x 10(-5) ml O2.mmHg-1.ml-1, and (3.26 +/- 1.01) x 10(-2) ml O2.beat-1.100 g LV-1, respectively]. However, the goodness of the linear fit of the VO2-PVA relation decreased after 90 min (r = 0.94 control, 0.62 at 90 min, and 0.64 at 120 min). Therefore, we conclude that the isolated bovine red cell-perfused rabbit heart preparation is stable for mechanical and energetic studies for at least 60 min.


1960 ◽  
Vol 199 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Abraham Guz ◽  
George S. Kurland ◽  
A. Stone Freedberg

Coronary flow, heart rate, myocardial oxygen consumption and Walton strain gauge tension were determined in the isolated rabbit heart perfused with hemoglobin solutions of varying oxygen content. Perfusion was carried out under constant pressure and with the hemoglobin solution in equilibrium with 3% CO2 and 97% air under atmospheric tension. Oxygen content was varied from 2 to 18 vol. % by diluting hemoglobin with Ringer-Locke solution. Change from a higher to lower oxyhemoglobin concentration resulted in increased coronary flow; the reserve led to decreased flow. Heart rate, myocardial tension and oxygen consumption were constant at oxygen capacity above 2 vol. %.


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