Nitric oxide synthesis in rat cardiac myocytes and fibroblasts.
We investigated nitric oxide (NO) synthase activity in cultured neonatal rat cardiac myocytes and fibroblasts upon treatment with interleukin 1 beta (IL-1 beta) and lipopolysaccharide (LPS). Incubation of cardiac myocytes for 24 h with IL-1 beta or LPS caused a significant increase in NO and cGMP production. Simultaneous incubation of IL-1 beta with NG-monomethyl-L-arginine or transforming growth factor beta (TGF-beta) completely inhibited the IL-1 beta-induced NO and cGMP production in cardiac myocytes. In contrast, incubation of cardiac fibroblasts for 24 h with IL-1 beta or LPS showed no significant effect on NO or cGMP production. Addition of IL-1 beta decreased the beating rate of cardiac myocytes, but TGF-beta overcame that inhibition. These observations suggest the presence of iNOS in cardiac myocytes, which is an important regulator of contractile function of the heart.
Shindo
T
T
Department of Cardiology, Jichi Medical School, Tochigi, Japan.
Ikeda
U
U
Ohkawa
F
F
Takahashi
M
M
Funayama
H
H
Nishinaga
M
M
Kawahara
Y
Y
Yokoyama
M
M
Kasahara
T
T
Shimada
K
K
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000096:biosynthesis; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism*; D006321:Heart / Q000187:drug effects; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D009206:Myocardium / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D051381:Rats; D017207:Rats, Sprague-Dawley
D007375:Interleukin-1; D008070:Lipopolysaccharides; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D006152:Cyclic GMP