EFFECT OF A NEW NITRIC-OXIDE DONOR ON THE BIOMECHANICAL PERFORMANCE OF THE ISOLATED ISCHEMIC RAT-HEART

The effect of a new nitric oxide (NO) donor, a meso-ionic 3-aryl subst ituted oxatriazole-5-imine derivative, GEA 3162 was studied on constan t flow-perfused ischaemic Langendorff rat heart. The perfusion was kep t constant at a rate of 16 mL min(-1). Ischaemia was induced by a low flow rate of 0.8 mL min(-1) for 30 min, and was followed by a 40-minut e reperfusion. In the first set of experiments the effects of GEA 3162 -infusion were examined on perfusion pressure, left ventricular pressu re, heart rate and left ventricular dP/dt. GEA 3162 infusion did not a ffect the pre-ischaemic maximum of left ventricular pressure. During r eperfusion, maximal left ventricular pressure, maximal and minimal dP/ dt values in the GEA 3162-treated group significantly exceeded those o f the untreated controls (by 19.3, 36.0 and 18.046, respectively). Dur ing reperfusion, perfusion pressure increased continuously in the cont rol group indicating an increasing coronary resistance, but it was kep t at a continuous low level with GEA 3162 treatment. In a second set o f experiments bradykinin was infused in order to lest the endothelial function before ischaemia and during late reperfusion. Bradykinin elic ited significant vasodilation in the control group during reperfusion, meanwhile it did not cause further change in coronary resistance in t he GEA 3162-infused group. We suggest, that GEA 3162 may have a protec tive effect on isolated rat heart in ischaemia and reperfusion, that r esults in an improved cardiac performance compared with untreated hear ts.