The isolated perfused heart system, as originated by Oscar Langendorff nearly a century ago has become a mainstay of pharmacological and physiological research. The system allows the examination of cardiac inotropic, chronotropic and vascular effects without the complications of an intact animal model. The original design has evolved to encompass both constant pressure and constant flow models in both recirculating and non-recirculating modes, as well as Working Heart mode. The Radnoti perfused heart systems has the capacity to function in any of these configurations, allowing the researcher to have maximal flexibility in experimental design.
Overview of #140101 Working Heart System
This version of the working heart system uses a peristaltic pump to generate the hydrostatic head for the constant pressure Langendorff preparation that initially sustains the heart. Perfusate is drawn from the High Volume 5-liter water jacketed reservoir, routed through the atrial bubble trap and diverted up to the aortic bubble trap at the atrial cannula. After the heart has stabilized, the researcher changes the direction of flow via a set of tubing clamps at “Y” connectors acting as a 3-way valve at the atrial cannula to switch from retrograde to working heart mode by directing perfusate into the left atria under hydrostatic pressure (5 mm Hg nominal, adjustable). The perfusate then enters the left ventricle and is pumped by the heart against an adjustable pressure head set by the researcher. After load may be adjusted on the aortic line to vary resistance by incorporating the supplied compliance loop on the aortic side during working heart mode. Buffer may be directed to waste following the compliance loop or directed to the 140144 Large Volume Sheet Flow Oxygenating chamber for re-gassing and returned to the heart. At this point the main 5-liter High Flow buffer reservoir supply may be omitted from the circuit and a nominal fixed volume (set by the researcher) re-circulated through the system.
- Supports Isolated Working Heart Mode (Neely)
- #140101BEZ is suitable for large hearts including porcine.
- Supports all Langendorff Modes in addition to Working Heart
- Atrial compliance loop: simulates physiological preload
- After load compliance loop: simulates physiological after load and mimics normal vascular elasticity.
- Independently adjustable preload and after load pressure
- Preparations may be spontaneously beating or paced using Radnoti #140157 Pacing Electrode
- Superb temperature control due to our water-jacketed heart chamber, components and water-jacketed key perfusate line tubing. Start-up to 37°C in 15 mins with less than 0.01° C error.
- Quick and easy disassembly due to our quick-disconnect tubing.
- Easy system maintenance and long-term durability due to GLP-compliant open architecture and no moving/active parts on compliance loops.
- Easy cleaning: our crystal clear borosilicate glassware is fully autoclavable and unlike plastic systems, are not affected by agents and proteins.
- Easy replacement: Individual components allow for easy replacement in the event of breakage and can be replaced without factory return.
- Customized configurations available. As with all Radnoti systems, the modular design allows for extreme flexibility and system reconfigurations.
- Due to the large scale of the apparatus and the donor heart, instrumentation is easily accommodated.
The system can be instrumented to measure:
- Perfusate Flow
- Ejection Flow
- Perfusate Pressure
- Cardiac Output
- Optical Imaging
- Apical Force
- Cardiac Pacing
If the experimenter is not conversant with cardiovascular pharmacology and physiology, there are a number of excellent texts that will introduce this area to you. Besides the medical physiology and pharmacology standards, there are a number of specialized texts. Pharmacologic Analysis of Drug-receptor Interaction by Terrence P. Kenakin (Raven Press, ny, 1987) is a compact text with practical emphasis on isolated tissues and organs in pharmacological research.