Abstract
The effects of arginine on nitric oxide synthase (NOS) activity and NO production were studied in pulmonary artery endothelial cells (PAEC). Incubation of PAEC with 0-100 μM arginine increased NO production, detected as nitrite in the culture medium, in a dose- dependent manner. In contrast, incubation with concentrations of arginine in excess of 100 μM resulted in a reversible dose-dependent inhibition of NO production, even though intracellular arginine content increased in these cells. The NOS enzyme kinetics were studied in a total membrane preparation and in purified NOS protein and revealed that the K(m) of arginine as a substrate for NOS is 3-5 μM, the V(max) occurred at 100 μM arginine, and substrate inhibition occurred at >100 μM arginine. Oxyhemoglobin, carboxy-PTIO, catalase, SOD, citrulline, hydroxyarginine, and D-arginine did not change NOS kinetics. Those results indicate that substrate inhibition of eNOS exists in porcine PAEC in vitro.
Original language | English (US) |
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Pages (from-to) | 469-475 |
Number of pages | 7 |
Journal | Nitric Oxide - Biology and Chemistry |
Volume | 1 |
Issue number | 6 |
DOIs | |
State | Published - Dec 1997 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Clinical Biochemistry
- Cancer Research