Dissociation of left ventricular hypertrophy, β-Myosin Heavy Chain gene expression, and myosin isoform switch in rats after ascending aortic stenosis
Background Reexpression of the fetal β-myosin heavy chain (β-MHC) gene was reported to be a marker for phenotypic reprogramming and cardiac hypertrophy in rats. Recent in vitro studies strongly suggested a role of angiotensin II for phenotypic reprogramming. In the present investigation, β-MHC gene...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
4 March 1997
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| In: |
Circulation
Year: 1997, Volume: 95, Issue: 5, Pages: 1253-1259 |
| ISSN: | 1524-4539 |
| DOI: | 10.1161/01.CIR.95.5.1253 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1161/01.CIR.95.5.1253 Verlag, lizenzpflichtig, Volltext: https://www.ahajournals.org/doi/10.1161/01.CIR.95.5.1253 
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| Author Notes: | Rudolf J. Wiesner, Heimo Ehmke, Jörg Faulhaber, Radovan Zak, J. Caspar Rüegg |
| Summary: | Background Reexpression of the fetal β-myosin heavy chain (β-MHC) gene was reported to be a marker for phenotypic reprogramming and cardiac hypertrophy in rats. Recent in vitro studies strongly suggested a role of angiotensin II for phenotypic reprogramming. In the present investigation, β-MHC gene expression was studied in an experimental model of pressure-overload hypertrophy that is not associated with a concurrent activation of the circulating renin-angiotensin system. - Methods and Results Hypertrophy was induced in rats by ascending aortic banding (n=40). After 7 days, myosin contained 31% (P<.05) of the β-MHC isoform in banded but <5% in sham-operated animals. However, no specific elevation of β-MHC mRNA levels was found in banded animals. In contrast, hearts of rats with abdominal aortic banding displayed a marked increase in β-MHC mRNA levels (3-fold to 5-fold, P<.05). Both the left ventricular weight and left ventricular peak systolic pressure were significantly elevated compared with sham-operated animals (abdominal aortic banding, +13% and 164±7 mm Hg; ascending aortic banding, +27% and 191±9 mm Hg). Plasma renin activity was elevated in rats with abdominal aortic banding (2.5-fold, P<.05) but not in rats with ascending aortic banding. - Conclusions The results of the present work do not support the concept that increased β-MHC gene expression is a general “stable late marker” of myocardial hypertrophy in rats. Our results suggest that the stimulation of the renin-angiotensin system is crucial for the activation of the β-MHC gene. |
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| Item Description: | Gesehen am 04.12.2024 |
| Physical Description: | Online Resource |
| ISSN: | 1524-4539 |
| DOI: | 10.1161/01.CIR.95.5.1253 |