Myocardial high energy phosphates and function as influenced by di- or trivalent cations and isoproterenol or DBcAMP.
The effects of Mn++, La+++ and Co++ (2 mM) with and without ISO or DBcAMP were investigated in isolated perfused rat hearts concerning mechanical and metabolic parameters. Mn++ and La+++ produce cardiac arrest accompanied by unchanged content of high energy phosphates. ISO or DBcAMP resp. administered together with these cations do not exhibit characteristic effects. Co++ induces cardiac arrest as well, but in addition severe reduction of high energy phosphate stores and O2-consumption. The effects of Co++ can be partly prevented by administration of ISO and elevated extracellular Ca++ concentration concerning mechanical parameters and oxygen consumption, whereas high energy phosphate stores remain low. The results obtained demonstrated that the Ca++ antagonistic ions studied show the expected metabolic consequences of EC-uncoupling only in the case of Mn++ and La+++. Co++ ions induce in additions to cardiac arrest and low O2-consumption severe reduction of high energy phosphate stores indicating disturbance of respiratory control of mitochondria.
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002412:Cations / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010725:Phosphocreatine / Q000378:metabolism; D051381:Rats
D002412:Cations; D009943:Organophosphorus Compounds; D010725:Phosphocreatine; D000244:Adenosine Diphosphate; D003994:Bucladesine; D000255:Adenosine Triphosphate; D007545:Isoproterenol