Comparative effects of L-NNA and alkyl esters of L-NNA on pulmonary vasodilator responses to ACh, BK, and SP.

Journal Article (Journal Article)

The comparative effects of the nitric oxide (NO) synthase inhibitors N omega-nitro-L-arginine (L-NNA), N omega-nitro-L-arginine methyl ester (L-NAME), and N omega-nitro-L-arginine benzyl ester (L-NABE) on baseline tone and on vasodilator responses to acetylcholine (ACh), bradykinin (BK), and substance P (SP) were compared in the pulmonary vascular bed of the cat under constant flow conditions. After administration of the NO synthase inhibitors in intravenous doses of 100 mg/kg, the increase in lobar arterial pressure and the attenuation of vasodilator responses to ACh, BK, and SP were similar, whereas responses to adenosine and felodipine, endothelium-independent vasodilator agents, were not altered. In addition to inhibiting responses to ACh, BK, and substance P, the NO synthase inhibitors enhanced vasodilator responses to S-nitroso-N-acetylpenicillamine and NO. Moreover, atropine inhibited pulmonary vasodilator responses to ACh but not to SP or BK, and L-NAME or L-NABE had no effect on the decrease in heart rate in response to efferent vagal stimulation, a muscarinic receptor-mediated response that is independent of NO release. The similar inhibitory effects of L-NNA, L-NAME, and L-NABE on vasodilator responses to ACh, BK, and SP suggest that the L-arginine analogue, L-NNA, as well as the methyl and benzyl esters of L-NNA are useful probes for studying NO-mediated endothelium-dependent responses in the pulmonary vascular bed of the intact-chest cat.(ABSTRACT TRUNCATED AT 250 WORDS)

Full Text

Duke Authors

Cited Authors

  • Cheng, DY; DeWitt, BJ; McMahon, TJ; Kadowitz, PJ

Published Date

  • June 1, 1994

Published In

Volume / Issue

  • 266 / 6 Pt 2

Start / End Page

  • H2416 - H2422

PubMed ID

  • 7517647

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpheart.1994.266.6.H2416


  • eng

Conference Location

  • United States