Release of secondary free radicals during post-ischaemic reperfusion is not influenced by extracellular calcium levels in isolated rat hearts

摘要: In this study, we evaluated the impact of calcium concentration present in perfusion medium (1.2-3 mM) on contractile performance, lactate dehydrogenase (LDH) release and secondary free radical production during post-ischaemic reperfusion isolated rat hearts. The was investigated using Electron Paramagnetic Resonance (EPR) technique spin trapping with lipophilic trap alpha-phenyl N-tert-butylnitrone (PBN). evolution left ventricular end diastolic pressure (LVEDP) both groups followed same pattern, but observed that ischaemic contracture more severe group hearts perfused 3 mM as compared those 1.2 calcium. A large alkyl/alkoxyl species occurred all from onset remained at a high level 30 min no return to basal values. kinetics intensity these releases were groups. conclusion, range extracellular levels mM), alkyl/alkoxyls radicals does not seem be calcium-dependent. Due protective actions PBN itself, results simultaneous investigations effects scavengers heart function may limited. However, since many pharmacological properties (antioxidant, cellular protector, NO precursor ...) are attributed PBN, studies investigating oxidative stress such multi-faceted tool make interpretation difficult.