Experimental study of the relationship between perfluoro-octyl bromide emulsion and norepinephrine release in reperfusion arrhythmia: isolated guinea pig heart model.

Perfluoro-octyl bromide (PFOB), one of the perfluorochemical oxygen transporters, improved postischemic cardiac dysfunctions. Also norepinephrine (NE) is one of the important inducible factors on reperfusion arrhythmias (ventricular fibrillation [VF]). We used these methods to evaluate the relationship between PFOB emulsion and NE release on reperfusion arrhythmias. The perfusion of isolated guinea pig hearts was employed: each of four groups of 6-7 hearts were used with Krebs-Henseleit solution (KHS) as control, and KHS with 5%, 15%, or 30% PFOB emulsion. The hearts were perfused in a constant pressure Langendorff model, stabilized for 30 min, followed by 30 min preischemia, then 30 min ischemia and 45 min reperfusion at normothermia. PFOB emulsion dose-dependently limited VF and inhibited NE release in reperfusion. Only 30% PFOB emulsion showed the significant improvement of VF (p=0.05). In hemodynamic parameters, only 5% PFOB emulsion showed a significant decrease in reperfusion, but there was no difference in coronary flow rate (CFR). No differences among the four groups were demonstrated in cardiac oxygen metabolic parameters. It was most likely that a high concentration of PFOB emulsion attenuated reperfusion arrhythmia by decreasing NE release.