Human platelets perfusion through isolated guinea-pig heart: the effects on coronary flow and oxidative stress markers.

Present study was designed to evaluate effect of perfusion with human platelets reach plasma (PRP) on coronary flow (CF) and oxidative stress markers in coronary vascular bed of the isolated guinea-pig heart. In coronary venous effluent the following oxidative stress markers were estimated: nitrite as a measure of nitric oxide (NO) production, superoxide anion (O2(-)), and index of lipid peroxidation (TBARS). Isolated guinea-pig hearts (n = 6, b.m. 250-300 g) were perfused according to a Langendorff's technique at different (30, 70, and 120 cmH2O) coronary perfusion pressures (CPP). Samples were collected at control conditions and during perfusion with platelets rich plasma (PRP) obtained either from healthy volunteers or from patients with acute myocardial infarction (PRP (AMI)) with/or without previous inhibition of NO synthase (NOS) by Nomega-nitro-L-arginine monomethyl ester (L-NAME, 30 micromol/l). PRP and PRP (AMI) perfusion induced reduction of CF and all evaluated oxidative stress parameters. The reduction of CF was more potentiated in PRP (AMI) as in PRP group, while oxidative stress parameters where significantly decreased only in PRP (AMI). In addition, previous blockade of NOS by L-NAME potentiated these effects only in PRP (AMI) group. It can be concluded that non-activated and activated platelets interact with coronary endothelium in similar way, with more significant influence of activated platelets on CF and oxidative stress markers.