Performance of the Isolated and Perfused Working Heart of the Teleost Conger-conger - Study of the Inotropic Effect of Prostacyclin

An in vitro preparation of the heart of the teleostConger conger, isolated without the pericardium, was set up. The procedure allowed subambient pressures to develop in the perfusion chamber during contraction, mimicking the in vivo situation with the pericardium intact. The ventricle produced a cardiac output of about 15 ml·min-1·kg wet body weight-1 at subambient input pressure, and was able to double the stroke work with an increase of preload up to about 0.2 kPa. Using this preparation it was found that prostacyclin has a positive inotropic effect on the atrium and ventricle, but it does not affect the heart rate. Semilogarithmic doseresponse curves of prostacyclin on the atrium are reported, showing a threshold concentration of about 10-9 M. The isolated and perfusedConger conger heart provides a useful model for a detailed analysis of the action of prostacyclin on myocardial contractility.