Nitric oxide production by cultured human aortic smooth muscle cells: stimulation by fluid flow.
This study demonstrated that exposure of cultured human aortic smooth muscle cells (SMC) to fluid flow resulted in nitric oxide (NO) production, monitored by nitrite and guanosine 3',5'-cyclic monophosphate production. A rapid burst in nitrite production rate was followed by a more gradual increase throughout the period of flow exposure. Neither the initial burst nor the prolonged nitrite production was dependent on the level of shear stress in the range of 1.1-25 dyn/cm2. Repeated exposure to shear stress after a 30-min static period restimulated nitrite production similar to the initial burst. Ca(2+)-calmodulin antagonists blocked the initial burst in nitrite release. An inhibitor of nitric oxide synthase (NOS) blocked nitrite production, indicating that changes in nitrite reflect NO production. Treatment with dexamethasone or cycloheximide had no effect on nitrite production. Monoclonal antibodies directed against the inducible and endothelial NOS isoforms showed no immunoreactivity on Western blots, whereas monoclonal antibodies directed against the neuronal NOS gave specific products. These findings suggest that human aortic SMC express a constitutive neuronal NOS isoform, the enzymatic activity of which is modulated by flow.
Papadaki
M
M
Cox Laboratory for Biomedical Engineering, Institute of Biosciences and Bioengineering, Rice University, Houston 77251, USA.
Tilton
R G
RG
Eskin
S G
SG
McIntire
L V
LV
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001012:Aorta, Abdominal; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000502:physiology; D002478:Cells, Cultured; D002648:Child; D017077:Culture Media, Conditioned; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052248:Nitric Oxide Synthase Type I; D009573:Nitrites / Q000378:metabolism; D012212:Rheology
D000911:Antibodies, Monoclonal; D002147:Calmodulin; D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D009573:Nitrites; D009569:Nitric Oxide; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D006152:Cyclic GMP; D002118:Calcium