Multitracer Stable Isotope Quantification of Arginase and Nitric Oxide Synthase Activity in a Mouse Model of Pseudomonas Lung Infection
| Autor: | Mahroukh Rafii, Hailu Huang, Hartmut Grasemann, Paul B. Pencharz, Felix Ratjen, Anne Mehl, Thomas Jaecklin |
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| Rok vydání: | 2014 |
| Předmět: |
Article Subject
Isolated lung perfusion Immunology Nitric oxide Mice 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Pseudomonas lcsh:Pathology Citrulline medicine Animals Lung 030304 developmental biology 0303 health sciences Kidney Arginase biology Cell Biology respiratory system Ornithine Molecular biology 3. Good health Mice Inbred C57BL Nitric oxide synthase Disease Models Animal medicine.anatomical_structure 030228 respiratory system Biochemistry chemistry biology.protein Female Nitric Oxide Synthase Research Article lcsh:RB1-214 |
| Zdroj: | Mediators of Inflammation, Vol 2014 (2014) Mediators of Inflammation |
| ISSN: | 1466-1861 0962-9351 |
| DOI: | 10.1155/2014/323526 |
| Popis: | Cystic fibrosis airways are deficient for L-arginine, a substrate for nitric oxide synthases (NOSs) and arginases. The rationale for this study was to quantify NOS and arginase activity in the mouse lung. Anesthetized unventilated mice received a primed constant stable isotope intravenous infusion containing labeled L-arginine, ornithine, and citrulline. The isotopic enrichment of each of the infused isotopomers and its product amino acids were measured in plasma and organ homogenates using liquid chromatography-tandem mass spectrometry. The effect of infection was studied three days after direct tracheal instillation of Pseudomonas-coated agar beads. In the infusion model, lung infection resulted in a significant (28-fold) increase in NOS activity in lung but not in trachea, kidney, liver, or plasma. Absolute rates of arginase activity in solid tissues could not be calculated in this model. In an isolated lung perfusion model used for comparison increased NOS activity in infected lungs was confirmed (28.5-fold) and lung arginase activity was increased 9.7-fold. The activity of L-arginine metabolizing enzymes can be measured using stable isotope conversion in the mouse. Accumulation of L-ornithine in the whole mouse model hindered the exact quantification of arginase activity in the lung, a problem that was overcome utilizing an isolated lung perfusion model. |
| Databáze: | OpenAIRE |
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