|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1Center of Vascular Biology, 2Department of Pathology and Laboratory Medicine, and 3Department of Pharmacology, Weill Medical College of Cornell University, New York, New York; and 4Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina
Submitted 17 October 2006 ; accepted in final form 25 August 2007
Diminished nitric oxide (NO) bioactivity and enhanced peroxynitrite formation have been implicated as major contributors to atherosclerotic vascular dysfunctions. Hallmark reactions of peroxynitrite include the accumulation of 3-nitrotyrosine (3-NT) in proteins and oxidation of the NO synthase (NOS) cofactor, tetrahydrobiopterin (BH4). The present study sought to 1) quantify the extent to which 3-NT accumulates and BH4 becomes oxidized in organs of apolipoprotein E-deficient (ApoE–/–) atherosclerotic mice and 2) determine the specific contribution of inducible NOS (iNOS) to these processes. Whereas protein 3-NT and oxidized BH4 were undetected or near the detection limit in heart, lung, and kidney of 3-wk-old ApoE–/– mice or ApoE–/– mice fed a regular chow diet for 24 wk, robust accumulation was evident after 24 wk on a Western (atherogenic) diet. Since 3-NT accumulation was diminished 3- to 20-fold in heart, lung, and liver in ApoE–/– mice missing iNOS, iNOS-derived species are involved in this reaction. In contrast, iNOS-derived species did not contribute to elevated protein 3-NT formation in kidney or brain. iNOS deletion also afforded marked protection against BH4 oxidation in heart, lung, and kidney of atherogenic ApoE–/– mice but not in brain or liver. These findings demonstrate that iNOS-derived species are increased during atherogenesis in ApoE–/– mice and that these species differentially contribute to protein 3-NT accumulation and BH4 oxidation in a tissue-selective manner. Since BH4 oxidation can switch the predominant NOS product from NO to superoxide, we predict that progressive NOS uncoupling is likely to drive atherogenic vascular dysfunctions.
inducible nitric oxide synthase; high-fat diet
This article has been cited by other articles:
![]() |
Z. L. S. Brookes, C. C. McGown, and C. S. Reilly Statins for all: the new premed? Br. J. Anaesth., July 1, 2009; 103(1): 99 - 107. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Ponnuswamy, E. Ostermeier, A. Schrottle, J. Chen, P. L. Huang, G. Ertl, B. Nieswandt, and P. J. Kuhlencordt Oxidative Stress and Compartment of Gene Expression Determine Proatherosclerotic Effects of Inducible Nitric Oxide Synthase Am. J. Pathol., June 1, 2009; 174(6): 2400 - 2410. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |