The effect of chemical sympathectomy on mitochondrial function in the ischaemic and reperfused myocardium.
1 Isolated rabbit hearts were perfused aerobically for 120 min, made ischaemic for 90 min, or made ischaemic for 90 min and then reperfused for 30 min. 2 Some rabbits were pretreated with 6-hydroxydopamine (6-OHDA), given as three separate intravenous doses of 30, 20 and 20 mg/kg, 20 to 48 h before they were killed; others (controls) received saline according to the same regime. 3 Mitochondria were harvested from left ventricular homogenates and their function assessed by measuring state 3O2 consumption (state 3 QO2), respiratory control index (RCI), phosphate: oxygen ratio (ADP:O), Ca2+ content, and ATP-producing activity. In other experiments peak left ventricular developed tension was recorded. 4 In hearts from saline-treated animals, mitochondrial state 3 QO2, RCI and ATP producing activities were reduced after global ischaemia, with or without reperfusion. There was a small gain in mitochondrial Ca2+ after ischaemia, and a large gain upon reperfusion. 5 6-OHDA pretreatment provided some protection against the effects of ischaemia and reperfusion on mitochondrial function and on peak developed tension. 6 It was concluded that chemical sympathectomy with 6-OHDA does not duplicate the effect of prolonged beta-adrenoceptor blockade in protecting mitochondrial function against the deleterious effects of ischaemia and reperfusion.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D003327:Coronary Disease / Q000378:metabolism*; D006892:Hydroxydopamines / Q000494:pharmacology; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D011817:Rabbits; D012129:Respiratory Function Tests; D013563:Sympathectomy, Chemical
D002395:Catecholamines; D006892:Hydroxydopamines; D000255:Adenosine Triphosphate; D002118:Calcium