The conservation of mitochondrial function by ischaemia--the ischaemia paradox.
The aim of this study was to compare oxidative phosphorylation of rat heart mitochondria, isolated: (i) immediately after excision of the heart; (ii) after 60 min of low flow normoxic perfusion; (iii) after 60 min of high flow normoxic perfusion;: (iv) after 30 min of no-flow ischaemia and (v) after 30 min ischaemia followed by 20 min reperfusion. The results, using a retrogradely perfused rat hart as a model, show that mitochondrial oxidative phosphorylation after 30 min of no-flow ischaemia showed no difference from oxidative phosphorylation measured on mitochondria isolated directly after excision of the heart. However, after 30 min no-flow ischaemia followed by 20 min of reperfusion, oxidative phosphorylation deteriorated in comparison with oxidative phosphorylation after 30 min of ischaemia only. Furthermore, oxidative phosphorylation after 60 min of non-ischaemic high flow perfusion (thus high coronary flow), compared better with oxidative phosphorylation after ischaemia-reperfusion than with oxidative phosphorylation after ischaemia alone.
Steinmann
C M
CM
Department of Physiology, Medical Faculty, University of Pretoria, South Africa.
Storm
M
M
D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000378:metabolism*; D015425:Myocardial Reperfusion; D010085:Oxidative Phosphorylation; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains