Endothelial nitric oxide synthase is a site of superoxide synthesis in endothelial cells treated with glyceryl trinitrate

Wayne H. Kaesemeyer, Alison A. Ogonowski, Liming Jin, Ruth B. Caldwell, Robert W. Caldwell

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

1. Tolerance to glyceryl trinitrate (GTN) involves superoxide (O2-) production by endothelial cells. Nitric oxide synthase (NOS) produces O2- when L-arginine (L-arg) is limited. The purpose of this study was to test the hypothesis that GTN stimulates NOS to increase O2- synthesis in endothelial cells when L-arg is limited. 2. Production of O2- by bovine aortic endothelial cells (BAEC passages 3-5) was determined by spectrophotometrically measuring superoxide dismutase-inhibited reduction of ferricytochrome C to ferrocytochrome C. Cells were incubated in buffer without L-arg. O2- production was measured using BAEC either untreated or treated with L-NAME or L-arg alone or following treatment with GTN (10-9 to 10-6 M) for 30 min or DPTA NONOate (10-7 and 10-6 M) alone or with GTN or DPTA NONOate after pretreatment with nitro-L-arginine methyl ester (L-NAME), L-arg or their inactive enantiomers, D-NAME or D-arg (all 5 x 10-4 M) (n = 6-7/group). 3. L-NAME alone produced a 69% reduction in O2- levels. Treatment with L-arg alone had no effect. Cells treated with GTN alone exhibited an increase in O2-. This effect was prevented by pretreatment with either L-NAME or L-arg, and was unaffected by D-NAME or D-arg. We observed a dose-response relationship in O2- production to GTN over a range of 10-9 to 10-7 M. 4. The NO donor, DPTA-NONOate, unlike GTN, did not have a significant effect on O2- production. 5. In conclusion, endothelial NOS is a site of O2- synthesis in endothelial cells activated by GTN.

Original languageEnglish (US)
Pages (from-to)1019-1023
Number of pages5
JournalBritish Journal of Pharmacology
Volume131
Issue number5
DOIs
StatePublished - 2000

Keywords

  • Endothelial nitric oxide synthase
  • Glyceryl trinitrate (nitroglycerin)
  • L-arginine
  • Nitrate tolerance
  • Superoxide anion

ASJC Scopus subject areas

  • Pharmacology

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