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AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase.

Publication ,  Journal Article
Privratsky, JR; Wold, LE; Sowers, JR; Quinn, MT; Ren, J
Published in: Hypertension
August 2003

Enhanced tissue angiotensin (Ang) II levels have been reported in diabetes and might lead to cardiac dysfunction through oxidative stress. This study examined the effect of blocking the Ang II type 1 (AT1) receptor on high glucose-induced cardiac contractile dysfunction. Rat ventricular myocytes were maintained in normal- (NG, 5.5 mmol/L) or high- (HG, 25.5 mmol/L) glucose medium for 24 hours. Mechanical and intracellular Ca2+ properties were assessed as peak shortening (PS), time to PS (TPS), time to 90% relengthening (TR90), maximal velocity of shortening/relengthening (+/-dL/dt), and intracellular Ca2+ decay (tau). HG myocytes exhibited normal PS; decreased +/-dL/dt; and prolonged TPS, TR90, and tau. Interestingly, the HG-induced abnormalities were prevented with the AT1 blocker L-158,809 (10 to 1000 nmol/L) but not the Janus kinase-2 (JAK2) inhibitor AG-490 (10 to 100 micromol/L). The only effect of AT1 blockade on NG myocytes was enhanced PS at 1000 nmol/L. AT1 antagonist-elicited cardiac protection against HG was nullified by the NADPH oxidase activator sodium dodecyl sulfate (80 micromol/L) and mimicked by the NADPH oxidase inhibitors diphenyleneiodonium (10 micromol/L) or apocynin (100 micromol/L). Western blot analysis confirmed that the protein abundance of NADPH oxidase subunit p47phox and the AT1 but not the AT2 receptor was enhanced in HG myocytes. In addition, the HG-induced increase of p47phox was prevented by L-158,809. Enhanced reactive oxygen species production observed in HG myocytes was prevented by AT1 blockade or NADPH oxidase inhibition. Collectively, our data suggest that local Ang II, acting via AT1 receptor-mediated NADPH oxidase activation, is involved in hyperglycemia-induced cardiomyocyte dysfunction, which might play a role in diabetic cardiomyopathy.

Duke Scholars

Published In

Hypertension

DOI

EISSN

1524-4563

Publication Date

August 2003

Volume

42

Issue

2

Start / End Page

206 / 212

Location

United States

Related Subject Headings

  • Tetrazoles
  • Sodium Dodecyl Sulfate
  • Receptors, Angiotensin
  • Receptor, Angiotensin, Type 2
  • Receptor, Angiotensin, Type 1
  • Reactive Oxygen Species
  • Rats, Sprague-Dawley
  • Rats
  • Proto-Oncogene Proteins
  • Protein-Tyrosine Kinases
 

Citation

APA
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ICMJE
MLA
NLM
Privratsky, J. R., Wold, L. E., Sowers, J. R., Quinn, M. T., & Ren, J. (2003). AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase. Hypertension, 42(2), 206–212. https://doi.org/10.1161/01.HYP.0000082814.62655.85
Privratsky, Jamie R., Loren E. Wold, James R. Sowers, Mark T. Quinn, and Jun Ren. “AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase.Hypertension 42, no. 2 (August 2003): 206–12. https://doi.org/10.1161/01.HYP.0000082814.62655.85.
Privratsky JR, Wold LE, Sowers JR, Quinn MT, Ren J. AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase. Hypertension. 2003 Aug;42(2):206–12.
Privratsky, Jamie R., et al. “AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase.Hypertension, vol. 42, no. 2, Aug. 2003, pp. 206–12. Pubmed, doi:10.1161/01.HYP.0000082814.62655.85.
Privratsky JR, Wold LE, Sowers JR, Quinn MT, Ren J. AT1 blockade prevents glucose-induced cardiac dysfunction in ventricular myocytes: role of the AT1 receptor and NADPH oxidase. Hypertension. 2003 Aug;42(2):206–212.

Published In

Hypertension

DOI

EISSN

1524-4563

Publication Date

August 2003

Volume

42

Issue

2

Start / End Page

206 / 212

Location

United States

Related Subject Headings

  • Tetrazoles
  • Sodium Dodecyl Sulfate
  • Receptors, Angiotensin
  • Receptor, Angiotensin, Type 2
  • Receptor, Angiotensin, Type 1
  • Reactive Oxygen Species
  • Rats, Sprague-Dawley
  • Rats
  • Proto-Oncogene Proteins
  • Protein-Tyrosine Kinases