Free radical-induced damage of cardiac sarcolemma (SL) and activity loss of beta-receptor adenylate cyclase system (beta-RAS). A comparison of the time courses.
In vitro studies have demonstrated that free radicals generated by Fe2+/Vit. C alter the beta-RAS function. SH-oxidation, peroxidation of sarcolemmal lipids and reaction of aldehydes (formed by lipid peroxidation) with the beta-RAS may contribute to this effect. In order to clarify the role of these reactions in respect to their ability to alter the beta-RAS function the time course of SH-oxidation, lipid peroxidation and formation of aldehyde reaction products has been studied. As result it is shown that SH-oxidation is nearly completed within 5 minutes and lipid peroxidation within 30 minutes after exposure to Fe2+/Vit. C. During this time period there was only a very small amount of aldehyde reaction products detectable. Therefore SH-oxidation and/or lipid peroxidation should be responsible for the activity loss of the beta-RAS.
Schimke
I
I
Institute of Pathological and Clinical Biochemistry, Humboldt-University, Berlin, GDR.
Haberland
A
A
Will-Shahab
L
L
Kuttner
I
I
Papies
B
B
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D005296:Ferrous Compounds / Q000494:pharmacology*; D005609:Free Radicals; D006321:Heart / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013552:Swine
D005296:Ferrous Compounds; D005609:Free Radicals; D011943:Receptors, Adrenergic, beta; C051140:iron(II)-ascorbic acid complex; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D001205:Ascorbic Acid