Circulatory models for the replacement of animal models

Animal experiments play a big role in the development of new pharmaceutical products. Millions of experimental animals are used each year for this purpose. For ethical, but also for scientific reasons an attempt is made, to replace at least a part of these animal experiments by an alternative method. This method comprises the usage of slaughterhouse organs such as kidney, heart, liver or limb. To enable the physiologic functions of these organs the former surrounding body is simulated. This is achieved by perfusing the organs with blood under proper pressure and to keep the blood in proper composition and everything at proper temperature. The following artificial organs are used to achieve this: a pulsatile blood pump for the convective transport of blood, an oxygenator and a dialysator for the mass-transfer, a heat-exchanger for the heat-transfer. A newly designed blood pump generates a flow by a force acting on a blood bag. This pump is computer-controlled and can either generate a continuous or pulsatile flow. The mass-transfer is achieved with a standard oxygenator module (Jostra M5) and an artificial kidney (Fresenius F4) module. The artificial circulation set-up has been developed with regard to (1) minimize blood damage and to optimize (2) the reproducibility of the experiments and (3) the user-friendliness. The artificial circulation has been built and successfully used in numerous experiments perfusing the porcine kidney. With minor modification the set-up is used to perfuse other organs.