Event: 933

Key Event Title


KE6 : Depletion, Nitric Oxide

Short name


Depletion, Nitric Oxide

Biological Context


Level of Biological Organization

Cell term


Organ term


Organ term

Key Event Components


Process Object Action
nitric oxide biosynthetic process nitric oxide decreased

Key Event Overview

AOPs Including This Key Event


AOP Name Role of event in AOP
Hypertension KeyEvent



Taxonomic Applicability


Term Scientific Term Evidence Link
Homo sapiens Homo sapiens High NCBI
Bos taurus Bos taurus High NCBI
Mus musculus Mus musculus High NCBI
Rattus norvegicus Rattus norvegicus High NCBI

Life Stages


Life stage Evidence
All life stages High

Sex Applicability


Term Evidence
Unspecific High

Key Event Description


Nitric oxide (NO), constitutively produced by endothelial nitric oxide synthase (eNOS), is an important regulator of vascular homeostasis. Endothelial-derived NO promotes vasodilation and protects against atherogenesis through the inhibition of vascular smooth muscle cell proliferation and migration, platelet aggregation and adhesion, and leukocyte adherence. Its effects have an influence on vascular resistance, blood pressure, vascular remodeling and angiogenesis (Luo et al., 2000). Dysfunctional eNOS as a result of eNOS uncoupling leads to a decrease or loss of NO bioavailability and an elevation of superoxide production (Crabtree et al., 2009). The imbalance of NO and superoxide is associated with many disorders, such as hypertension, atherosclerosis, hypercholesterolemia, and diabetes mellitus.

How It Is Measured or Detected


NO production can be measured through the conversion of L-arginine to L-citrulline (de Bono et al., 2007) , in situ fluorescent signal detection with fluorescent indicator DAF-2 DA (Itoh et al., 2000; Nagata et al., 1999; Qiu et al., 2001), EPR spin-trapping (Xia et al., 2000), and the determination of total nitrate and nitrite concentration (Crabtree et al., 2009; Du et al., 2013).

Domain of Applicability


NO depletion was observed in humans, cows, mice and rats (Chen et al., 2010; Crabtree et al., 2009; De Pascali et al., 2014; Du et al., 2013; Jayaram et al., 2015).

Evidence for Perturbation by Stressor



de Bono, J.P., Warrick, N., Bendall, J.K., Channon, K.M., and Alp, N.J. (2007). Radiochemical HPLC detection of arginine metabolism: Measurement of nitric oxide synthesis and arginase activity in vascular tissue. Nitric Oxide 16, 1–9.

Chen, X., Xu, J., Feng, Z., Fan, M., Han, J., and Yang, Z. (2010). Simvastatin combined with nifedipine enhances endothelial cell protection by inhibiting ROS generation and activating Akt phosphorylation. Acta Pharmacol. Sin. 31, 813–820.

Crabtree, M.J., Tatham, A.L., Al-Wakeel, Y., Warrick, N., Hale, A.B., Cai, S., Channon, K.M., and Alp, N.J. (2009). Quantitative regulation of intracellular endothelial nitric-oxide synthase (eNOS) coupling by both tetrahydrobiopterin-eNOS stoichiometry and biopterin redox status: insights from cells with tet-regulated GTP cyclohydrolase I expression. J. Biol. Chem. 284, 1136–1144.

De Pascali, F., Hemann, C., Samons, K., Chen, C.-A., and Zweier, J.L. (2014). Hypoxia and reoxygenation induce endothelial nitric oxide synthase uncoupling in endothelial cells through tetrahydrobiopterin depletion and S-glutathionylation. Biochemistry (Mosc.) 53, 3679–3688.

Du, Y., Navab, M., Shen, M., Hill, J., Pakbin, P., Sioutas, C., Hsiai, T.K., and Li, R. (2013). Ambient ultrafine particles reduce endothelial nitric oxide production via S-glutathionylation of eNOS. Biochem. Biophys. Res. Commun. 436, 462–466.

Dumitrescu, C., Biondi, R., Xia, Y., Cardounel, A.J., Druhan, L.J., Ambrosio, G., and Zweier, J.L. (2007). Myocardial ischemia results in tetrahydrobiopterin (BH4) oxidation with impaired endothelial function ameliorated by BH4. Proc. Natl. Acad. Sci. U. S. A. 104, 15081–15086.

Itoh, Y., Ma, F.H., Hoshi, H., Oka, M., Noda, K., Ukai, Y., Kojima, H., Nagano, T., and Toda, N. (2000). Determination and bioimaging method for nitric oxide in biological specimens by diaminofluorescein fluorometry. Anal. Biochem. 287, 203–209.

Jayaram, R., Goodfellow, N., Zhang, M.H., Reilly, S., Crabtree, M., De Silva, R., Sayeed, R., and Casadei, B. (2015). Molecular mechanisms of myocardial nitroso-redox imbalance during on-pump cardiac surgery. Lancet Lond. Engl. 385 Suppl 1, S49.

Luo, Z., Fujio, Y., Kureishi, Y., Rudic, R.D., Daumerie, G., Fulton, D., Sessa, W.C., and Walsh, K. (2000). Acute modulation of endothelial Akt/PKB activity alters nitric oxide–dependent vasomotor activity in vivo. J. Clin. Invest. 106, 493–499.

Nagata, N., Momose, K., and Ishida, Y. (1999). Inhibitory effects of catecholamines and anti-oxidants on the fluorescence reaction of 4,5-diaminofluorescein, DAF-2, a novel indicator of nitric oxide. J. Biochem. (Tokyo) 125, 658–661.

Qiu, W., Kass, D.A., Hu, Q., and Ziegelstein, R.C. (2001). Determinants of shear stress-stimulated endothelial nitric oxide production assessed in real-time by 4,5-diaminofluorescein fluorescence. Biochem. Biophys. Res. Commun. 286, 328–335.

Xia, Y., Cardounel, A.J., Vanin, A.F., and Zweier, J.L. (2000). Electron paramagnetic resonance spectroscopy with N-methyl-D-glucamine dithiocarbamate iron complexes distinguishes nitric oxide and nitroxyl anion in a redox-dependent manner: applications in identifying nitrogen monoxide products from nitric oxide synthase. Free Radic. Biol. Med. 29, 793–797.