Prostacyclin-mediated compensatory mechanism in the coronary circulation during acute NO synthase blockade

Zsombor Lacza, László Dézsi, Krisztina Káldi, Eszter M. Horváth, Péter Sándor, Zoltán Benyó

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10 Citations (Scopus)


Nitric oxide (NO) in contrast to most prostanoids, plays a major role in the maintenance of coronary arterial tone under physiological conditions. However, in case of endothelial damage or other NO-depleting situations the importance of other vasodilating mechanisms may be increased. The aim of the present study was to investigate the crosstalk between the L-arginine - NO and the prostanoid systems in isolated rat hearts. Coronary flow and cardiac dynamics were measured in a standard Langendorff perfusion system. Application of indomethacin in the perfusion media failed to change coronary flow. Administration of L-NA, however, significantly decreased coronary flow by 24.8 ± 2.3% (p < 0.01 vs. untreated control). In the presence of indomethacin, L-NA decreased coronary flow to an even greater extent by 35.8 ± 5.2% (p < 0.05 vs. L-NA alone). Treatment of the preparations with L-NA or indomethacin failed to change cardiac work, coapplication of both drugs together, however, decreased cardiac work by 45 ± 11% (p < 0.05 vs. untreated control). Heart rate remained constant throughout the experimental period and did not differ significantly between the treatment groups. The prostacyclin content of the effluent from the L-NA treated hearts was significantly higher than that of controls. We conclude that in case of decreased NO levels in the coronary circulation, arterial tone is maintained by prostacyclin production.

Original languageEnglish
Pages (from-to)1141-1149
Number of pages9
JournalLife Sciences
Issue number9
Publication statusPublished - Jul 18 2003



  • Coronary circulation
  • Endothelium
  • Nitric oxide
  • Prostacyclin

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

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