Scavenging of hypochlorous acid and of myoglobin-derived oxidants by the cardioprotective agent mercaptopropionylglycine.
Mercaptopropionylglycine (MPG) has a marked cardioprotective action in several model systems of ischaemia-reoxygenation injury. Suggested mechanisms of action include scavenging of hydroxyl radical and of hypochlorous acid and reacting with an oxidant formed by reaction of myoglobin with H2O2, thereby slowing lipid peroxidation stimulated by myoglobin-H2O2 mixtures. This oxidant seems not to be singlet O2 or hydroxyl radical. Studies in vitro show that scavenging of hypochlorous acid is a feasible mechanism of cardioprotective action for MPG in vivo in ischaemia/reperfusion systems to which neutrophil-mediated injury contributes. However, the poor ability of MPG to inhibit lipid peroxidation stimulated by myoglobin/H2O2 mixtures and its ability to increase iron ion release from myoglobin in the presence of a large excess of H2O2 suggests that MPG is unlikely to protect the myocardium by interfering with oxidants produced by the myoglobin-H2O2 system.
Puppo
A
A
Laboratoire de Biologie Végètale, Université de Nice, France.
Cecchini
R
R
Aruoma
O I
OI
Bolli
R
R
Halliwell
B
B
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000378:metabolism; D006997:Hypochlorous Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009211:Myoglobin / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D008625:Tiopronin / Q000494:pharmacology*
D002317:Cardiovascular Agents; D005609:Free Radicals; D009211:Myoglobin; D006997:Hypochlorous Acid; D006861:Hydrogen Peroxide; D008625:Tiopronin; D001205:Ascorbic Acid