Skip to main content
  • Poster presentation
  • Open access
  • Published:

Evaluation of ODQ as specific inhibitor of NO-sensitive guanylyl cyclase using mice deficient for the enzyme

The NO/cGMP signal transduction is involved in the regulation of a variety of physiological processes e.g. smooth muscle relaxation and platelet aggregation. As signalling molecule, NO has diverse effects with NO-sensitive guanylyl cyclase (NO-GC) being accepted as the most important NO receptor. To differentiate between cGMP-dependent and -independent effects of NO inhibitors for the NO-GC are broadly used. The commonly used inhibitor for NO-GC is ODQ (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one). The precise mechanism of NO-GC inhibition by ODQ remains unclear.

Recently, we have generated mice deficient in NO-GC (GC-KO). GC-KO mice show a pronounced increase in blood pressure, underlining the importance of NO in the regulation of smooth muscle tone in vivo. We showed a total lack of NO affecting smooth muscle tone and platelet aggregation which confirms NO-GC as the only NO target regulating these two functions in mice.

Using these KO mice we can evaluate the specificity of ODQ as inhibitor of NO-GC. In fact, ODQ used at low μM concentrations is a good inhibitor of cGMP signalling, allowing its use to investigate the cGMP dependence of NO effects. However, high NO concentrations elicited relaxation responses in ODQ-treated WT smooth muscle via NO-GC as they were absent in GC-KO tissue. This shows that NO-induced effects in the presence of ODQ do not necessarily indicate cGMP independence.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Dieter Groneberg.

Rights and permissions

Open Access This article is published under license to BioMed Central Ltd. This is an Open Access article is distributed under the terms of the Creative Commons Attribution 2.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and permissions

About this article

Cite this article

Groneberg, D., Koesling, D. & Friebe, A. Evaluation of ODQ as specific inhibitor of NO-sensitive guanylyl cyclase using mice deficient for the enzyme. BMC Pharmacol 9 (Suppl 1), P18 (2009).

Download citation

  • Published:

  • DOI: