Effect of Temperature and Coronary Flow on the Metabolic and Mechanical Function of the Isolated Rat Heart

Cardiology ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 238-248 ◽  
Author(s):  
Haywood Blum ◽  
Tamas Ivanics ◽  
Danning Zhang ◽  
Krzysztof Wroblewski ◽  
Mary D. Osbakken
1999 ◽  
Vol 276 (6) ◽  
pp. H2076-H2084 ◽  
Author(s):  
Robert D. Lasley ◽  
Prakash Narayan ◽  
M. Salik Jahania ◽  
Elizabeth L. Partin ◽  
Kathleen R. Kraft ◽  
...  

The purpose of this study was to compare the hemodynamic effects of the adenosine A3-receptor agonists N 6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-β-d-ribofuranosyl]adenine (IB-MECA) and 2-chloro- N 6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-β-d-ribofuranosyl]adenine (Cl-IB-MECA) in isolated rat and rabbit hearts and in the intact, open-chest pig. Isolated hearts perfused with Krebs-Henseleit buffer at a constant pressure (70 mmHg) were treated with 50 nM of either IB-MECA or Cl-IB-MECA. Neither IB-MECA nor Cl-IB-MECA altered ventricular function or heart rate in the isolated rat and rabbit hearts, and neither agent altered coronary flow in the rabbit. However, 2 min of IB-MECA treatment in the isolated rat heart increased coronary flow by 25%, an effect that did not exhibit tachyphylaxis. The IB-MECA-induced coronary dilation was only partially attenuated by the adenosine A3-receptor antagonist MRS-1191 (50 nM). IB-MECA-induced coronary dilation was completely blocked by the adenosine A2a-receptor antagonist 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine (Sch-58261, 50 nM). Cl-IB-MECA (50 nM) did not increase coronary flow in the rat, but 100 nM did increase flow by 18%. In pentobarbital sodium-anesthetized pigs IB-MECA (5 μg/kg iv) decreased systemic blood pressure and increased pulmonary artery pressure, effects that did exhibit tachyphylaxis. These results illustrate that adenosine A3-receptor agonists produce species-dependent effects, which in the rat heart appear to be caused by adenosine A2a-receptor activation.


2018 ◽  
Vol 37 (05) ◽  
pp. 515-525 ◽  
Author(s):  
I. M. Stojic ◽  
V. Lj. Jakovljevic ◽  
V. I. Zivkovic ◽  
I. M. Srejovic ◽  
T. R. Nikolic ◽  
...  

1993 ◽  
Vol 264 (3) ◽  
pp. H783-H790 ◽  
Author(s):  
C. Ibuki ◽  
D. J. Hearse ◽  
M. Avkiran

Transient (2 min) acidic (pH 6.6) reperfusion with low [HCO3-] solution suppresses reperfusion-induced ventricular fibrillation (VF) in the isolated rat heart. Using this preparation, we tested whether the effect was mediated by the high [H+] or the low [HCO3-] of perfusate. Left and right coronary beds were independently perfused with HCO3(-)-containing (25.0 mmol/l) solution at pH 7.4. Regional ischemia was then induced by stopping flow to the left coronary bed for 10 min. Hearts were subsequently assigned to four groups (n = 12 hearts/group), and the left coronary bed was reperfused with either HCO3(-)-containing (25.0 or 4.0 mmol/l) or HCO3(-)-free (5.0 mmol/l HEPES) solution, at pH 7.4 throughout (control reperfusion) or at pH 6.6 for the first 2 min and at pH 7.4 from 2 to 5 min (acidic reperfusion). Regardless of the buffer, controls exhibited a high (92 and 100%) incidence of VF; this was reduced to 42% in both of the acidic reperfusion groups (P < 0.05). There were no intergroup differences in heart rate, coronary flow, or size of ischemic zone. Thus high [H+], rather than low [HCO3-], appears to mediate the antifibrillatory effect of transient acidic reperfusion.


1976 ◽  
Vol 41 (4) ◽  
pp. 603-607 ◽  
Author(s):  
M. A. Duvelleroy ◽  
M. Duruble ◽  
J. L. Martin ◽  
B. Teisseire ◽  
J. Droulez ◽  
...  

We describe a method for perfusion of a working isolated rat heart with washed erythrocytes suspended in a Krebs-Henseleit bicarbonate buffer containing bovine albumin (fraction V). With washed pig red cells, as hematocritwas varied between 0 and 40%, coronary flow (CF), aortic flow (AF), external work (W), and myocardial oxygen consumption (MVO2) were measured. Hemodynamic data at a hematocrit of 30% (CF = 5.4 +/- 0.7 ml/min per g, AF = 75 +/- 8 ml/min per g) were identical with those reported for the intact animal.Coronary sinus PO2 was highest with a red cell-free perfusate suggesting that coronary flow is partially shunted. Human red cells obtained from bankedblood, were tried also with success. With careful filtration, the preparation is stable for 2 h and well suited for study of the dynamics of myocardial oxygen delivery.


Life Sciences ◽  
2002 ◽  
Vol 70 (10) ◽  
pp. 1121-1128 ◽  
Author(s):  
Alvair P. Almeida ◽  
Steyner F. Côrtes ◽  
Anderson J. Ferreira ◽  
Virgı́nia S. Lemos

2001 ◽  
Vol 442 (7) ◽  
pp. r198-r199
Author(s):  
Cvetka Grašič Kuhar ◽  
Matjaž Bunc ◽  
Gorazd Drevenšek ◽  
Metka V Budihna ◽  
Dušan šuput

2016 ◽  
Vol 94 (10) ◽  
pp. 1048-1057 ◽  
Author(s):  
Tamara R. Nikolic ◽  
Vladimir I. Zivkovic ◽  
Ivan M. Srejovic ◽  
Dragan S. Radovanovic ◽  
Nevena S. Jeremic ◽  
...  

Despite worldwide use of anabolic steroids in last decades, there is still contradictory information about their acute influence on myocardium. The aim of this study was to examine the acute effects of nandrolone decanoate (ND) on cardiodynamics and coronary flow in isolated rat heart. The hearts of male Wistar albino rats (n = 48, 12 per group, age 8 weeks, body mass 180–200 g) were excised and perfused according to the Langendorff technique at gradually increased coronary perfusion pressures (40–120 cmH2O). After the control sets of experiments, the hearts in different groups were perfused with different doses of ND (1, 10, or 100 μmol/L separately). Using a sensor placed in the left ventricle, we registered maximum and minimum rate of pressure development in the left ventricle (dP/dtmax and dP/dtmin), systolic and diastolic left ventricular pressure (SLVP and DLVP), and heart rate (HR). Coronary flow (CF) was measured flowmetrically. The results clearly show the depression in cardiac function caused by higher doses of ND. The highest concentration of ND (100 μmol/L) induced the most deleterious impact on the myocardial function and perfusion of the heart (coronary circulation), which could be of clinical significance.


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