Effect of ischemia on heart submitochondrial superoxide production.
NADH-dependent formation of superoxide anions (O2-) by rabbit cardiac submitochondrial particles (SMP) was stimulated after exposure of the isolated heart to 90 min of ischemic perfusion. This effect was more evident in the rotenone-inhibited region of the respiratory electron chain in comparison to the antimycin-inhibited region. The kinetic study of the NADH-dependent reaction showed that at the level of the rotenone-inhibited region, ischemia reduced Km value for NADH, differently from the antimycin-inhibited region where the kinetic constants remain unchanged. No significant changes of the Vmax values were observed in both SMP-producing O2- sites. The ischemic perfusions also produced a reduction of mitochondrial function, particularly evident when glutamate as substrate was studied.
Guarnieri
C
C
Istituto di Chimica Biologica dell'Università di Bologna, Italy.
Muscari
C
C
Ventura
C
C
Mavelli
I
I
D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D003326:Coronary Circulation; D003327:Coronary Disease / Q000378:metabolism*; D004579:Electron Transport; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D010101:Oxygen Consumption; D010477:Perfusion; D011817:Rabbits; D012016:Reference Values; D012402:Rotenone / Q000494:pharmacology; D013367:Submitochondrial Particles / Q000187:drug effects / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism*
D012402:Rotenone; D013481:Superoxides; D000968:Antimycin A