Isolated Heart Preparations Perfused or Superfused with Balanced Salt Solutions

Abstract

Hearts of small laboratory animals (rats, guinea pigs, small rabbits, and cats) are frequently used for either isolated work-performing (antegrade or anagrade perfused) or Langendorff (retrograde perfused) heart preparations. Muscle strips from the atria and strips and/or papillary muscles from the ventricles of these hearts provide excellent specimens for heart muscle preparations immersed in or superfused with balanced salt solutions (BSS). Muscle strip preparations, especially atrial and ventricular trabeculae preparations and Purkinje fibers, are also used from dog, sheep, and pig hearts and, occasionally, from small portions of human hearts excised during open-heart surgery. The long-term viability of the preparations is greatly enhanced by the prevention of intravascular coagulation of blood and by removal of blood from the heart tissues at the time of sacrifice. For this reason, we always pretreat the experimental animals, including dogs, with intraperitoneal (i.p.) or intravenous (i.v.) injections of 5000 IU heparin/kg body weight and wash out, immediately after sacrifice, the coronary arterial and venous system with warm or cold BSS, dependent on the type of preparation we use (see below).