Activation and Functional Significance of the Renin-Angiotensin System in Mice With Cardiac Restricted Overexpression of Tumor Necrosis Factor
| Autor: | Anje Christina Höper, Theresa A. Brinsa, Douglas L. Mann, Chih Chang Wei, Richard A. Bond, Ronald M Peshock, Abhinav Diwan, Natarajan Sivasubramanian, Francis G. Spinale, Kenda L. J. Evans, Louis J. Dell’Italia, Markus Flesch |
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| Rok vydání: | 2003 |
| Předmět: |
Genetically modified mouse
medicine.medical_specialty Angiotensin receptor Angiotensinogen Cardiomegaly Mice Transgenic Peptidyl-Dipeptidase A Receptor Angiotensin Type 2 Losartan Receptor Angiotensin Type 1 Renin-Angiotensin System Angiotensin Receptor Antagonists Mice Physiology (medical) Homologous desensitization Internal medicine Renin Renin–angiotensin system medicine Animals RNA Messenger Receptor Receptors Angiotensin Ventricular Remodeling Tumor Necrosis Factor-alpha business.industry Angiotensin II Myocardium Body Weight Age Factors Hemodynamics Organ Size Endocrinology Organ Specificity Apoptosis Tumor necrosis factor alpha Collagen Angiotensin I Cardiology and Cardiovascular Medicine business |
| Zdroj: | Circulation. 108:598-604 |
| ISSN: | 1524-4539 0009-7322 |
| DOI: | 10.1161/01.cir.0000081768.13378.bf |
| Popis: | Background— The functional significance of cross-regulation between the renin-angiotensin system (RAS) and tumor necrosis factor (TNF) has been established in nonmyocyte cell types; however, the degree and functional significance of the interaction between RAS and TNF has not been characterized in the heart. Methods and Results— We examined the expression of components of the RAS in a line of transgenic mice (MHCsTNF) with cardiac restricted overexpression of TNF. When examined at 4, 8, and 12 weeks of age, the MHCsTNF mice had increased activation of myocardial RAS, as shown by an increase in ACE mRNA level and ACE activity and increased angiotensin II peptide levels. Furthermore, myocardial angiotensin receptor mRNA and protein levels were reduced in the MHCsTNF mice, consistent with homologous desensitization of the receptors. However, expression of renin and angiotensinogen was not increased in MHCsTNF mice compared with littermate controls. To determine the functional significance of RAS activation in the MHCsTNF mice, we treated the mice with an angiotensin type I receptor antagonist, losartan (30 mg/kg), or diluent from 4 to 8 weeks of age. Analysis of cardiac structure with MRI showed that treatment with losartan normalized left ventricular mass and wall thickness. Furthermore, treatment with losartan reduced myocardial collagen content and reduced the incidence of myocyte apoptosis. Conclusions— Taken together, these results show that there are functionally significant interactions between RAS and TNF in the heart and that these interactions play an important role in the development and progression of left ventricular remodeling. |
| Databáze: | OpenAIRE |
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