Powerlab 8sp chart 7

After rapid excision, the hearts were placed in ice-cold perfusion buffer, cannulated via the aorta and then perfused in the Langendorff mode with Krebs-Henseleit (KH) solution gassed with 95 % O 2 and 5 % CO 2 (pH 7.4) at constant perfusion pressure of 73 mm Hg and 37 °C. KH solution contained (in mmol/l): NaCl 118.0; KCl 3.2; MgSO 4 1.2; NaHCO 3 25.0; KH 2 PO 4 1.18; CaCl 2 2.5; glucose 11.1 or 22.2. Left ventricular (LV) pressure was measured by a water-filled balloon (inflated to obtain end-diastolic pressure of 5-7 mm Hg) inserted into LV and connected to a pressure transducer (MLP physiological pressure transducer, ADInstruments, Germany). LV systolic and diastolic pressure, LV developed pressure (LVDP; systolic minus diastolic pressure), maximal rates of pressure development and fall, +dP/dt max and -dP/dt max , as indexes of contraction and relaxation, heart rate (HR, derived from electrogram) and coronary flow were used to assess heart function using Power-Lab/8SP Chart 7 software (ADInstruments, Germany). The hearts were allowed to stabilize (20-40 min) before further interventions (Fig. 1).

Rats were anesthetized with thiopental (50-60 mg.kg -1 ) administered intraperitoneally together with heparin (500 IU). The hearts were rapidly excised, placed in ice-cold perfusion buffer, then cannulated via the aorta and perfused in the Langendorff mode at a constant perfusion pressure of 73 mm Hg and at 37 °C. The perfusion solution was a modified Krebs-Henseleit buffer gassed with O 2 and CO 2 (pH 7.4) containing (in mM): glucose 11.0; CaCl 2 1.6; NaCl 118.0; NaHCO 3 25.0; MgSO 4 1.18; KH 2 PO 4 1.28; KCl 3.0.
An epicardial electrogram (EG) was registered by means of two stainless steel electrodes attached to the apex of the heart and the aortic cannula and continuously recorded. Heart rate was calculated from the EG. Left ventricular pressure was measured by means of a nonelastic water-filled balloon inserted into the left ventricle via the left atrium and connected to a pressure transducer (MLP844, ADInstruments, Germany). Left ventricular systolic pressure (LVSP), LV diastolic pressure (LVEDP), LV developed pressure (LVDP, systolic minus diastolic pressure), maximal rates of pressure development [+(dP/dt) max ] and fall [-(dP/dt) max ] as the indexes of contraction and relaxation, as well as the heart rate (HR) and coronary flow (CF) were used to assess cardiac function. Heart function was analyzed using PowerLab/8SP Chart 7 software (ADInstruments, Germany).