Heart Langendorff-perfused isolated

Cytochemical Analysis of Na/K Pump Function in Langendorff-perfused Isolated Hearts Effect of Glutathione... 

The protective effects of the Mn(ii)-based SOD mimics against myocardial ischemia/reperfusion injury in the isolated rabbit heart and monkey heart have been investigated. Kilgore et subjected Langendorff perfused, isolated rabbit hearts to a 30 minute period of global ischemia followed by a 45 minute period of reperfusion. Upon reperfusion, an increase in left ventricular end-diastolic pressure occurred, which was attenuated when the hearts were perfused with 20/.iM SC-52608. Perfusion of SC-52608 also inhibited the release of creatine kinase and intracellular potassium, and reduced the extent of antibody binding to the intracellular protein myosin which occurs upon reperfusion of the ischemic heart. These studies indicated that SC-52608 is cardioprotective to the reperfused, ischemic isolated rabbit heart. 

Figure 4.11 Effect of glutathione on the reduction of myocardial Na/K ATPase activity associated with Ischaemia and reperfuslon. Isolated rat hearts were perfused in the Langendorff mode with oxygenated Tyrode s solution for a control period of 10 min. This was immediately followed by a 60 min period of global, stop-flow ischaemia and 5 min subsequent reperfuslon. Glutathione (GSH) (1 mM) was added to the perfusion fluid 5 min prior to the onset of Ischaemia and throughout the reperfuslon period. The data are presented as means standard errors of the means (n = 6).

Lan0endorff perfused isolated hearts. The Langendorff isolated perfused heart model is used to demonstrate adult ischemic myocardial preservation (24). 

In isolated perfused hearts, ventricular dysfunction may be due to myocardial stunning or lethal cell injury. In the Langendorff perfused ischemic rat hearts, ATP concentrations decrease rapidly to 60% in the first minute, with a rapid secondary decrease by 13 min due to contracture (33). Recovery from stunned to normal myocardium requires 24-48 h in the in vivo reperfused heart with coronary artery occlusion of 2-20 min (34). Dobrinina et al. (11) showed that neutral liposomes preserved liver integrity in rats subjected to hepatotropic poisons by non-specific mechanisms. However, histochemical infarct size data do not support this hypothesis in the myocardium (Fig. 3b). 

Attach the heart by the aorta to the cannula of the Langendorff apparatus. The cannula is placed into the cut aortic stump of the isolated heart to perfuse the coronary arteries retro-gradely. (The valve separating the aorta and the left ventricle is closed by the pressure in the aorta, and the perfusion fluid is forced through the coronary arteries.)... 

Isolated working heart preparation Perfusion of the heart ex vivo through the left atrium and ejection via the aorta resembling physiological conditions. Measurement of cardiac output. Preload and afterload can be adjusted. Other characteristics similar to Langendorff preparation. 

The effects of resveratol on the phosphate metabolism and contractility of the isolated Langendorff-perfused rat heart exposed to 20 min of no-flow... 

Isolated Hearts Similarly, an entire heart can be removed from an animal donor (e.g., rabbit) and studied in isolation via Langendorff perfusion using different modes of contraction such as isovolumetric (Qu et al., 2013) or working heart under various conditions of preload and afterload (Werchan and McDonough, 1987). This approach shares many of the characteristics of the isolated tissue approach, including the need for technical expertise to run... 

Different experimental techniques have been also used to investigate ischemia-reperfusion injury. Table 2. Experimental models of isolated hearts cannot consider the contribution of blood components or neurohormonal changes as this occurs in in vivo studies. However, these studies are able to dissect potential underlying mechanisms of the ischemic injury. The mode of perfusion (working heart vs Langendorff mode or constant flow vs constant pressure), the use of pacing, the composition of the perfusate and the end-points chosen to assess myocardial injury (arrhythmias, functional recovery... 

For this, we assessed the role of NO in the isolated spontaneously beating heart perfused at constant flow in a Langendorff apparatus. As shown in Fig. 4, stimulation of the sympathetic nerves originting from the stellate ganglia (4 Hz for 10 sec ) in the rat heart elicited a marked increase in heart rate and NE overflow. Perfusion with various NO donors [i.e., SNP (0.1 and 1 fiM) and SIN-1 and SNAP (both at 10 fxM)] failed to affect the heart rate (Fig. 4A), but markedly decreased perfusion pressure (i.e., it caused... 

Serbinova, E., Khwaja, S., and Catudioc, J., Palm oil vitamin E protects against ischaemia/reperfusion injury in the isolated perfused Langendorff heart, Nutr. Res., 12, S205-S215, 1996. 

In the isolated rat heart perfused according to Langendorff s technique, the 8-hydroxyguanine content in the DNA significantly increased after an ischaemia of 30 or 60 min followed by reperfusion with oxygenated Krebs-Henseleit buffer (You et al. 2000). The levels of 8-hydroxyguanine did not increase either in the ischaemic hearts reperfused with a nitrogenated solution or in the ischaemic-reperfused hearts treated with superoxide dismut-ase, mannitol or allopurinol. 

Hearts, isolated from Sprague-Dawley rats of either sex (280-368 g) with about 1 cm of the aorta attached, were gently squeezed to remove excess blood and then mounted on a Langendorff apparatus (Edinburgh University staff, 1971). Krebs-Henseleit solution at 37 C was perfused through the heart at a constant pressure and maintained at a constant temperature by circulating water (37°C) in the outer Jacket. After an equilibration period of 30-50 min, responses to the extract were obtained by adding individual bolus doses (0.1-10 mg) to the perfUsion medium. The developed tension was monitored isometrically by a Devices Mx4 pen recorder for 30-40 min after each dose, by which time the hearts had fully recovered from the effects of the extract. 

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