Essential role of nitric oxide in sepsis-induced impairment of endothelium-derived hyperpolarizing factor-mediated relaxation in rat pulmonary artery
| Autor: | Jaganathan Subramani, Vellanki Ravi Prakash, Kandaswamy Kathirvel, Marie Dennis Marcus Leo, Santosh K. Mishra, Rathinam Arunadevi, Thakur Uttam Singh |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Endothelium-derived hyperpolarizing factor medicine.medical_specialty Endothelium Vasodilation Pulmonary Artery Nitric Oxide Nitric oxide chemistry.chemical_compound Biological Factors Internal medicine Sepsis medicine Animals Endothelial dysfunction Rats Wistar Cyclic guanosine monophosphate Pharmacology Endothelium-Dependent Relaxing Factors biology business.industry medicine.disease Rats Nitric oxide synthase medicine.anatomical_structure Endocrinology chemistry Anesthesia cardiovascular system biology.protein Endothelium Vascular business Blood vessel |
| Zdroj: | European journal of pharmacology. 630(1-3) |
| ISSN: | 1879-0712 |
| Popis: | Both endothelial nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) are important vasodilators in pulmonary circulation. Sepsis is known to impair endothelium-dependent dilation in the pulmonary vasculature, but the mechanisms are incompletely understood. We have examined the relative contribution of EDHF/NO to the attenuated endothelium-dependent relaxation of pulmonary artery in sepsis, and the role of inducible nitric oxide synthase (iNOS)-derived NO in this mechanism. Sepsis was induced in male adult Wistar rats by caecal ligation and puncture. At 18h after surgery, left and right branches of pulmonary arteries were isolated for tension recording, NO/cyclic guanosine monophosphate (cGMP) measurements, mRNA and protein expressions. Despite a marked decrease in the arterial endothelial nitric oxide synthase (eNOS) mRNA and phosphorylated-eNOS (p-eNOS) protein expressions in sepsis, endothelium-dependent relaxation to acetylcholine (ACh) mediated by NO, acetylcholine-stimulated NO release and tissue cGMP levels were moderately inhibited. Sepsis however abolished the N(G)-Nitro-l-arginine methyl ester (L-NAME)/indomethacin-resistant arterial relaxation (EDHF response) to acetylcholine in this vessel. In vitro treatment of the arterial rings from septic rats with 1400W, a selective inhibitor of iNOS restored the EDHF response, but had no effect on the acetylcholine-induced relaxation mediated by endothelial NO. The functional role of iNOS-derived NO in impairing EDHF-mediated relaxation was coincident with an increased basal NO production, iNOS mRNA and protein expressions in the rat pulmonary artery. In conclusion, the loss of the EDHF response may be primarily responsible for the endothelial dysfunction in sepsis, and its restoration by a selective iNOS inhibitor may improve pulmonary vasodilation. |
| Databáze: | OpenAIRE |
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