Endothelin-1 inhibits nitric oxide synthesis in vascular smooth muscle cells.
We investigated the effects of endothelin-1 on nitric oxide synthesis in vascular smooth muscle cells. We measured the production of nitrite, a stable metabolite of nitric oxide, and the expression of inducible nitric oxide synthase mRNA and protein in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/mL) for 24 hours caused a significant increase in nitrite production. Endothelin-1 significantly decreased the interleukin-1 beta-induced nitrite production by vascular smooth muscle cells in a dose-dependent manner (10(-11) to 10(-8) mol/L). Incubation with interleukin-1 beta for 24 hours induced expression of inducible nitric oxide synthase mRNA and protein in vascular smooth muscle cells, whereas endothelin-1 showed a suppressive effect on their expressions. Addition of the endothelin type A receptor antagonist BQ-485, but not the endothelin type B receptor antagonist BQ-788, dose-dependently inhibited the effect of endothelin-1. After protein kinase C activity was functionally depleted by treatment of cells with phorbol 12-myristate 13-acetate for 24 hours, the effect of endothelin-1 was abolished. These results indicate that endothelin-1 acts on endothelin type A receptors and inhibits nitric oxide synthesis in interleukin-1 beta-stimulated vascular smooth muscle cells at least partially through a protein kinase C-dependent pathway.
Ikeda
U
U
Department of Cardiology, Jichi Medical School, Tochigi, Japan. uikeda@jichi.ac.jp
Yamamoto
K
K
Maeda
Y
Y
Shimpo
M
M
Kanbe
T
T
Shimada
K
K
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D007375:Interleukin-1 / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017466:Receptors, Endothelin / Q000378:metabolism; D013997:Time Factors
D001381:Azepines; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D007375:Interleukin-1; D009842:Oligopeptides; D010880:Piperidines; D012333:RNA, Messenger; D017466:Receptors, Endothelin; C083116:BQ 485; D009569:Nitric Oxide; C086539:BQ 788; D019001:Nitric Oxide Synthase; D011493:Protein Kinase C