Dissociation of left ventricular hypertrophy, β-Myosin Heavy Chain gene expression, and myosin isoform switch in rats after ascending aortic stenosis

• Verfasst von: Wiesner, Rudolf J. [VerfasserIn]
• Verfasst von: Ehmke, Heimo [VerfasserIn]
• Verfasst von: Faulhaber, Jörg [VerfasserIn]
• Verfasst von: Zak, Radovan [VerfasserIn]
• Verfasst von: Rüegg, Johann Caspar [VerfasserIn]
• Titel: Dissociation of left ventricular hypertrophy, β-Myosin Heavy Chain gene expression, and myosin isoform switch in rats after ascending aortic stenosis
• Verf.angabe: Rudolf J. Wiesner, Heimo Ehmke, Jörg Faulhaber, Radovan Zak, J. Caspar Rüegg
• E-Jahr: 1997
• Jahr: 4 March 1997
• Umfang: 7 S.
• Fussnoten: Gesehen am 04.12.2024
• Titel Quelle: Enthalten in: Circulation
• Ort Quelle: Philadelphia, Pa. : Lippincott, Williams & Wilkins, 1950
• Jahr Quelle: 1997
• Band/Heft Quelle: 95(1997), 5, Seite 1253-1259
• ISSN Quelle: 1524-4539
• DOI: doi:10.1161/01.CIR.95.5.1253
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1910818178

Abstract

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.