scholarly journals Substrate competition in postischemic myocardium. Effect of substrate availability during reperfusion on metabolic and contractile recovery in isolated rat hearts.

1994 ◽  
Vol 75 (6) ◽  
pp. 1103-1112 ◽  
Author(s):  
C Tamm ◽  
R Benzi ◽  
I Papageorgiou ◽  
I Tardy ◽  
R Lerch
Keyword(s):  
Substrate Availability ◽  
Rat Hearts ◽  
Contractile Recovery ◽  
Postischemic Myocardium ◽  
Substrate Competition ◽  
Isolated Rat

scholarly journals Postischemic Na+-K+-ATPase reactivation is delayed in the absence of glycolytic ATP in isolated rat hearts

2001 ◽  
Vol 280 (5) ◽  
pp. H2189-H2195 ◽  
Author(s):  
Jan G. Van Emous ◽  
Carmen L. A. M. Vleggeert-Lankamp ◽  
Marcel G. J. Nederhoff ◽  
Tom J. C. Ruigrok ◽  
Cees J. A. Van Echteld
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Functional Coupling ◽  
Glycogen Depletion ◽  
Postischemic Reperfusion ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Glycolytic Atp ◽  
Contractile Recovery ◽  
Isolated Rat ◽  
Isolated Perfused Rat Hearts

Normalization of intracellular sodium (Na[Formula: see text]) after postischemic reperfusion depends on reactivation of the sarcolemmal Na+-K+-ATPase. To evaluate the requirement of glycolytic ATP for Na+-K+-ATPase function during postischemic reperfusion, 5-s time-resolution23Na NMR was performed in isolated perfused rat hearts. During 20 min of ischemia, Na[Formula: see text] increased approximately twofold. In glucose-reperfused hearts with or without prior preischemic glycogen depletion, Na[Formula: see text]decreased immediately upon postischemic reperfusion. In glycogen-depleted pyruvate-reperfused hearts, however, the decrease of Na[Formula: see text] was delayed by ∼25 s, and application of the pyruvate dehydrogenase (PDH) activator dichloroacetate (DA) did not shorten this delay. After 30 min of reperfusion, Na[Formula: see text]had almost normalized in all groups and contractile recovery was highest in the DA-treated hearts. In conclusion, some degree of functional coupling of glycolytic ATP and Na+-K+-ATPase activity exists, but glycolysis is not essential for recovery of Na[Formula: see text] homeostasis and contractility after prolonged reperfusion. Furthermore, the delayed Na+-K+-ATPase reactivation observed in pyruvate-reperfused hearts is not due to inhibition of PDH.

Contribution of prostaglandins to reperfusion-induced ventricular failure in isolated rat hearts

1986 ◽  
Vol 251 (1) ◽  
pp. H133-H140 ◽  
Author(s):  
M. Karmazyn
Keyword(s):  
Coronary Flow ◽  
Initial Period ◽  
Hydrolysis Product ◽  
Contractile Force ◽  
Ventricular Contractility ◽  
Endogenous Prostaglandin ◽  
Resting Tension ◽  
Rat Hearts ◽  
Contractile Recovery ◽  
Isolated Rat

This study was carried out to investigate the possible contribution of endogenous prostaglandin (PG) production to failure of contractile recovery following reperfusion of hypoperfused isolated rat hearts. A 90% reduction in coronary flow rate for 60 min resulted in a time-dependent depression of contractile force and an elevation in resting tension. Reperfusion produced a slight (approximately 11%) recovery of contractile force, whereas resting tension remained elevated. Reperfusion was a potent stimulus for PG (as assessed by 6 keto-PGF1 alpha) release and resulted in levels that were significantly higher than those observed prior to ischemia. When PG synthesis was inhibited by the nonsteroidal anti-inflammatory drugs ibuprofen, indomethacin, or acetylsalicylic acid (ASA), recovery of ventricular contractility on reperfusion was significantly higher than that seen in the absence of drugs. Ibuprofen was the most effective, producing an average recovery of 70% (P less than 0.05 from control). Indomethacin and ASA produced approximately a 40% (P less than 0.05) and 35% (P less than 0.05) recovery of contractile force, respectively. The improved recovery in contractility was significantly depressed by the addition of low concentrations of prostacyclin (PGI2) and PGF2 alpha, whereas PGE2 and 6 keto-PGF1 alpha, the hydrolysis product of PGI2, were ineffective. The effects on resting tension were inconsistent. PG release during reperfusion was unrelated either to the length of the initial period of reduced coronary flow or the degree of contractile recovery; it was attenuated either by a reduction in or by an elevation of Ca concentration. These results indicate that endogenous PGs mediate, at least in part, reperfusion-associated failure of ventricular function.

Independent dual perfusion of left and right coronary arteries in isolated rat hearts

1991 ◽  
Vol 261 (6) ◽  
pp. H2082-H2090 ◽  
Author(s):  
M. Avkiran ◽  
M. J. Curtis
Keyword(s):  
High Energy ◽  
Low Flow ◽  
Blue Dye ◽  
Ischemia And Reperfusion ◽  
Langendorff Preparation ◽  
Rat Hearts ◽  
Left And Right ◽  
Conventional Models ◽  
Aortic Cannula ◽  
Isolated Rat

A novel dual lumen aortic cannula was designed and constructed to permit independent perfusion of left and right coronary beds in isolated rat hearts without necessitating the cannulation of individual arteries. Stability of the dual-perfusion preparation was shown to be similar to that of the conventional Langendorff preparation, in terms of coronary flow, heart rate, and high-energy phosphate content. The independence of left and right perfusion beds was confirmed by unilateral infusion of disulfine blue dye and spectrophotometric detection of the dye in ventricular homogenates. Transient cessation of flow to the left coronary bed resulted in severe ventricular arrhythmias upon reperfusion, as in conventional models of regional ischemia and reperfusion. The dual-perfusion model is technically undemanding, reproducible, inexpensive, and can be used in several species. It enables studies with 1) regional low flow ischemia, 2) regional zero-flow ischemia without coronary ligation (with attendant damage to vasculature), 3) selective application of drugs or interventions to the ischemic-reperfused zone, and 4) selective application of components of ischemia and reperfusion to a site anatomically relevant to ischemic heart disease.

The Effects of Low-Flow Ischemia on K+Fluxes in Isolated Rat Hearts Assessed by87Rb NMR

1999 ◽  
Vol 31 (4) ◽  
pp. 817-826 ◽  
Author(s):  
V.V. Kupriyanov ◽  
B. Xiang ◽  
B. Kuzio ◽  
R. Deslauriers
Keyword(s):  
Low Flow ◽  
Rat Hearts ◽  
Isolated Rat

scholarly journals Attenuation of extracellular ATP response in cardiomyocytes isolated from hearts subjected to ischemia-reperfusion

2005 ◽  
Vol 289 (2) ◽  
pp. H614-H623 ◽  
Author(s):  
Harjot K. Saini ◽  
Vijayan Elimban ◽  
Naranjan S. Dhalla
Keyword(s):  
Cardiac Function ◽  
Positive Inotropic Effect ◽  
Ischemia Reperfusion ◽  
Cardiac Contractility ◽  
Extracellular Atp ◽  
Binding Characteristics ◽  
Rat Hearts ◽  
The Status ◽  
Intracellular Ca ◽  
Isolated Rat

Extracellular ATP is known to augment cardiac contractility by increasing intracellular Ca2+ concentration ([Ca2+]i) in cardiomyocytes; however, the status of ATP-mediated Ca2+ mobilization in hearts undergoing ischemia-reperfusion (I/R) has not been examined previously. In this study, therefore, isolated rat hearts were subjected to 10–30 min of global ischemia and 30 min of reperfusion, and the effect of extracellular ATP on [Ca2+]i was measured in purified cardiomyocytes by fura-2 microfluorometry. Reperfusion for 30 min of 20-min ischemic hearts, unlike 10-min ischemic hearts, revealed a partial depression in cardiac function and ATP-induced increase in [Ca2+]i; no changes in basal [Ca2+]i were evident in 10- or 20-min I/R preparations. On the other hand, reperfusion of 30-min ischemic hearts for 5, 15, or 30 min showed a marked depression in both cardiac function and ATP-induced increase in [Ca2+]i and a dramatic increase in basal [Ca2+]i. The positive inotropic effect of extracellular ATP was attenuated, and the maximal binding characteristics of 35S-labeled adenosine 5′-[γ-thio]triphosphate with crude membranes from hearts undergoing I/R was decreased. ATP-induced increase in [Ca2+]i in cardiomyocytes was depressed by verapamil and Cibacron Blue in both control and I/R hearts; however, this response in I/R hearts, unlike control hearts, was not affected by ryanodine. I/R-induced alterations in cardiac function and ATP-induced increase in [Ca2+]i were attenuated by treatment with an antioxidant mixture and by ischemic preconditioning. The observed changes due to I/R were simulated in hearts perfused with H2O2. The results suggest an impairment of extracellular ATP-induced Ca2+ mobilization in I/R hearts, and this defect appears to be mediated through oxidative stress.

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