Nitrolinoleate, a nitric oxide-derived mediator of cell function: synthesis, characterization, and vasomotor activity.
Nitric oxide (*NO) and *NO-derived reactive species rapidly react with lipids during both autocatalytic and enzymatic oxidation reactions to yield nitrated derivatives that serve as cell signaling molecules. Herein we report the synthesis, purification, characterization, and bioactivity of nitrolinoleate (LNO2). Nitroselenylation of linoleic acid yielded LNO2 that was purified by solvent extraction, silicic acid chromatography, and reverse-phase HPLC. Structural characterization was performed by IR spectroscopy, 15N-NMR, LC-negative ion electrospray mass spectroscopy (MS), and chemiluminescent nitrogen analysis. Quantitative MS analysis of cell and vessel LNO2 metabolism, using L[15N]O2 as an internal standard, revealed that LNO2 is rapidly metabolized by rat aortic smooth muscle (RASM) monolayers and rat thoracic aorta, resulting in nitrite production and up to 3-fold increases in cGMP (ED50 = 30 microM for RASM, 50 microM for aorta). LNO2 induced endothelium-independent relaxation of preconstricted rat aortic rings, which was unaffected by L(G)-nitro-l-arginine methyl ester addition and inhibited by the guanylate cyclase inhibitor 1H-[1,2,4] oxadiazole[4,3-a]quinoxalin-1-one and the *NO scavenger HbO2. These results reveal that synthetic LNO2, identical to lipid derivatives produced biologically by the reaction of *NO and *NO-derived species with oxidizing unsaturated fatty acids (e.g., linoleate), can transduce vascular signaling actions of *NO.
Lim
Dong Gun
DG
Departments of Anesthesiology, Biochemistry and Molecular Genetics, Medicine, and UAB Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
Sweeney
Scott
S
Bloodsworth
Allison
A
White
C Roger
CR
Chumley
Phillip H
PH
Krishna
N Rama
NR
Schopfer
Francisco
F
O'Donnell
Valerie B
VB
Eiserich
Jason P
JP
Freeman
Bruce A
BA
D000818:Animals; D001013:Aorta, Thoracic; D002851:Chromatography, High Pressure Liquid; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D007249:Inflammation; D008041:Linoleic Acids / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009574:Nitro Compounds / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D010069:Oxadiazoles / Q000494:pharmacology; D010084:Oxidation-Reduction; D010108:Oxyhemoglobins / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D014664:Vasodilation / Q000187:drug effects*
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D005231:Fatty Acids, Unsaturated; D016166:Free Radical Scavengers; D008041:Linoleic Acids; D009573:Nitrites; D009574:Nitro Compounds; D010069:Oxadiazoles; D010108:Oxyhemoglobins; D011810:Quinoxalines; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester