Endothelial cyclic GMP and cyclic AMP do not regulate the release of endothelium-derived relaxing factor/nitric oxide from bovine aortic endothelial cells.
The present study was designed to investigate whether cyclic GMP or cyclic AMP modulates the release of endothelium-derived relaxing factor/nitric oxide (EDRF/NO) in cultured bovine aortic endothelial cells (BAE cells). BAE cell-conditioned medium was transferred onto rat fetal lung fibroblasts (RFL-6 cells) and the increase in cyclic GMP in these cells was used as a sensitive bioassay of EDRF/NO activity. BAE cells released a material that markedly enhanced cyclic GMP in RFL-6 cells. The synthesis of this substance could be stimulated with bradykinin (10 nM) or Ca++ ionophore A23187 (1 microM) and was completely prevented by treatment of the BAE cells with the EDRF/NO synthesis inhibitors NG-nitro-L-arginine (100 microM) or NG-methyl-L-arginine (1 mM). Addition of hemoglobin (10 microM) or incubation of the RFL-6 detector cells with methylene blue (10 microM) also abolished the cyclic GMP increase in the RFL-6 cells. The release of EDRF/NO by bradykinin and A23187 was accompanied by an approximately 2-fold increase in the cyclic GMP content in the producing BAE cells (in the presence of the cyclic GMP phosphodiesterase inhibitor M&B 22,948, 0.1 mM). Incubation of BAE cells with atrial natriuretic peptide (0.1 microM) or sodium nitroprusside (10 microM) enhanced cyclic GMP content of BAE cells 6.5-fold and 4.1-fold, respectively (in the presence of M&B 22,948, 0.1 mM). These increases in the cyclic GMP levels in BAE cells had no effect on basal or bradykinin- and A23187-stimulated release of EDRF/NO. Bradykinin (10 nM) and A23187 (1 microM) also stimulated prostacyclin production in BAE cells 2.4-fold and 5.6-fold, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Kuhn
M
M
Department of Clinical Pharmacology, Hannover Medical School, Germany.
Otten
A
A
Frölich
J C
JC
Förstermann
U
U
D000818:Animals; D001011:Aorta / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000032:analysis / Q000502:physiology*; D006152:Cyclic GMP / Q000032:analysis / Q000502:physiology*; D004730:Endothelium, Vascular / Q000378:metabolism*; D011464:Epoprostenol / Q000096:biosynthesis; D009569:Nitric Oxide / Q000378:metabolism*; D019335:Nitroarginine; D011688:Purinones / Q000494:pharmacology
D011688:Purinones; D019335:Nitroarginine; D009569:Nitric Oxide; D000001:Calcimycin; D001120:Arginine; D011464:Epoprostenol; D000242:Cyclic AMP; C011145:zaprinast; D006152:Cyclic GMP