Metabolic blocker-induced cell damage in rat cardiac tissue. Comparison of three models currently used: the isolated perfused heart, heart cell cultures and isolated myocytes.

In a comparative study on metabolic blockade-induced cardiac cell damage, three different heart (cell) preparations are exposed to potassium cyanide (KCN) and iodoacetamide (IAA) in fixed concentrations (5 and 0.1 mmol/l, respectively). The preparations used are the perfused rat heart, isolated rat heart myocytes and rat heart cell cultures. Irreversible heart cell damage is reflected by the release of a cytoplasmic enzyme, LDH (lactate dehydrogenase), or HBDH (alpha-hydroxybutyrate dehydrogenase) from the heart (cell) preparations. Metabolic blockade-induced release of 50% of the originally intracellularly located LDH or HBDH is reached after 2-3 h from rat heart cell cultures, after 2-4 h from isolated rat heart myocytes and after variable (coronary flow-dependent) durations of perfusion from perfused rat hearts. It is concluded that to study the effect of toxic agents on myocytic integrity, the use of isolated cardiac myocytes and heart cell cultures is preferable to the use of isolated perfused hearts.