Metabolism of the lipid peroxidation product, 4-hydroxy-trans-2-nonenal, in isolated perfused rat heart.
The metabolism of 4-hydroxy-trans-2-nonenal (HNE), an alpha, beta-unsaturated aldehyde generated during lipid peroxidation, was studied in isolated perfused rat hearts. High performance liquid chromatography separation of radioactive metabolites recovered from [3H]HNE-treated hearts revealed four major peaks. Based on the retention times of synthesized standards, peak I, which accounted for 20% radioactivity administered to the heart, was identified to be due to glutathione conjugates of HNE. Peaks II and III, containing 2 and 37% radioactivity, were assigned to 1, 4-dihydroxy-2-nonene (DHN) and 4-hydroxy-2-nonenoic acid, respectively. Peak IV was due to unmetabolized HNE. The electrospray ionization mass spectrum of peak I revealed two prominent metabolites with m/z values corresponding to [M + H]+ of HNE and DHN conjugates with glutathione. The presence of 4-hydroxy-2-nonenoic acid in peak III was substantiated using gas chromatography-chemical ionization mass spectroscopy. When exposed to sorbinil, an inhibitor of aldose reductase, no GS-DHN was recovered in the coronary effluent, and treatment with cyanamide, an inhibitor of aldehyde dehydrogenase, attenuated 4-hydroxy-2-nonenoic acid formation. These results show that the major metabolic transformations of HNE in rat heart involve conjugation with glutathione and oxidation to 4-hydroxy-2-nonenoic acid. Further metabolism of the GS-HNE conjugate involves aldose reductase-mediated reduction, a reaction catalyzed in vitro by homogenous cardiac aldose reductase.
Srivastava
S
S
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas 77555-1067, USA.
Chandra
A
A
Wang
L F
LF
Seifert
W E
WE
DaGue
B B
BB
Ansari
N H
NH
Srivastava
S K
SK
Bhatnagar
A
A
D000447:Aldehydes / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D014316:Tritium
D000447:Aldehydes; D014316:Tritium; C027576:4-hydroxy-2-nonenal