Lysozyme binding to endocardial endothelium mediates myocardial depression by the nitric oxide guanosine 3',5' monophosphate pathway in sepsis
| Autor: | Ratna Bose, Steven N. Mink, Zhao-Qin Cheng, Deepak Bose, Diane E. Roberts, Hans Jacobs, Krika Duke, R. Bruce Light |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
medicine.medical_specialty
Endothelium Arginine Guanosine In Vitro Techniques Nitric Oxide Nitric oxide Contractility chemistry.chemical_compound Dogs Internal medicine Quinoxalines Sepsis medicine Animals Molecular Biology Cyclic guanosine monophosphate Cyclic GMP Oxadiazoles omega-N-Methylarginine biology Myocardium Cell Membrane Myocardial Contraction Nitric oxide synthase Endocrinology medicine.anatomical_structure chemistry cardiovascular system biology.protein Muramidase Cardiology and Cardiovascular Medicine Soluble guanylyl cyclase Endocardium |
| Zdroj: | Journal of molecular and cellular cardiology. 39(4) |
| ISSN: | 0022-2828 |
| Popis: | Inflammatory mediators have been implicated as a cause of reversible myocardial depression in septic shock. We previously reported that the release of lysozyme-c (Lmz-S) from leukocytes from the spleen or other organs contributes to myocardial dysfunction in Escherichia coli septic shock in dogs by binding to a cardiac membrane glycoprotein [J. Mol. Cell. Cardiol. 35 (2003) 265]. However, the mechanism by which Lzm-S causes this depression has not been elucidated. In the present study, we tested the hypothesis that the binding of Lzm-S to a membrane glycoprotein causes myocardial depression by the formation of nitric oxide (NO). NO generation then activates soluble guanylyl cyclase and increases cyclic guanosine monophosphate (cGMP), which in turn triggers contractile impairment via activation of cGMP-dependent protein kinase (PKG). We examined these possibilities in a right ventricular trabecular preparation in which isometric contraction was used to measure cardiac contractility. We found that Lzm-S's depressant effect could be prevented by the non-specific NO synthase (NOS) inhibitor NG-monomethyl- l -arginine ( l -NMMA). A guanylyl cyclase inhibitor (ODQ) and a PKG inhibitor (Rp-8-Br-cGMP) also attenuated Lzm-S's depressant effect as did chemical denudation of the endocardial endothelium (EE) with Triton X-100 (0.5%). In EE tissue, we further showed that Lzm-S caused NO release with use of 4,5 diaminofluorescein, a fluorescent dye that binds to NO. The present study shows that the binding of Lzm-S to EE generates NO, and that NO then activates the myocardial guanosine 3′,5′ monophosphate pathway leading to cardiac depression in sepsis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect