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Renin-angiotensin system in failing heart
- Source :
- Journal of molecular and cellular cardiology. 27(1)
- Publication Year :
- 1995
-
Abstract
- Extrahepatic synthesis and localization of angiotensinogen have been described in animals, thus establishing the tissue renin-angiotensin system. We examined angiotensinogen messenger RNA synthesis by northern blotting. It was detected not only in the liver, but also in both the atrial and ventricular heart tissues, suggesting that angiotensinogen is synthesized in the human heart. Immunohistochemical studies using a specific antibody to angiotensinogen revealed a stronger reaction in the endocardial layer of the human left ventricle, than in the epicardial layer, and intense immunoreactivity in the conduction system and right atrium. Furthermore, our experiments revealed a widespread immunopositive reaction for angiotensinogen in the left ventricle of diseased hearts. We examined the participation of the collagen in the occurrence and progression of cardiomyopathy. The acetic acid solubility of collagen and reducible crosslink decreased in cardiomyopathic hamsters as the fibrosis progressed, but was unchanged in controls. These findings indicate that in the early phase of cardiomyopathy the extracellular matrix of the myocardium is similar to immature tissues. In the later phase, the matrix resembles that of hard tissues, and is insoluble. Furthermore, we examined the relationship between angiotensin II and collagen synthesis. Basal collagen synthesis in cardiac fibroblasts from spontaneously hypertensive rats was 1.6-fold greater than that in Wistar-Kyoto rats. The responsiveness of collagen production to Ang II was significantly enhanced in SHR. This effect was angiotensin receptor-specific, because it was blocked by the competitive inhibitor. These results indicate angiotensin II may play an important role in collagen accumulation in hypertensive cardiac hypertrophy.
- Subjects :
- Angiotensin receptor
medicine.medical_specialty
Cardiomyopathy
Angiotensinogen
Gene Expression
Extracellular matrix
Renin-Angiotensin System
Fibrosis
Reference Values
Internal medicine
Renin–angiotensin system
medicine
Animals
Humans
cardiovascular diseases
Molecular Biology
biology
Chemistry
Angiotensin II
Myocardium
Angiotensin-converting enzyme
Heart
medicine.disease
Extracellular Matrix
medicine.anatomical_structure
Endocrinology
Ventricle
biology.protein
Collagen
Cardiology and Cardiovascular Medicine
Cardiomyopathies
Subjects
Details
- ISSN :
- 00222828
- Volume :
- 27
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Journal of molecular and cellular cardiology
- Accession number :
- edsair.doi.dedup.....1d493f7fd2b34d1f9c5aeed981dab9b2