Meeting details menu

Meeting Authors
Meeting Abstracts
Keynote lectures
Oral communications
Poster presentations
Special symposia
Other

Acta Physiologica Congress

Back

Acta Physiologica 2012; Volume 204, Supplement 689
91st Annual Meeting of The German Physiological Society
3/22/2012-3/25/2012
Dresden, Germany


SGK1 SENSITIVITY OF NA+/H+ EXCHANGER ACTIVITY AND CARDIAC REMODELING FOLLOWING PRESSURE OVERLOAD
Abstract number: O6

Volkl1 *J., Lin2 Y., Alesutan1 I., Ahmed1 M., Pasham1 V., Mia1 S., Gu1 S., Feger1 M., Saxena1 A., Metzler3 B., Kuhl4 D., Pichler2 B., Lang1 F.

1University of Tbingen, Department of Physiology, Tbingen, Germany
2University of Tbingen, Preclinical Imaging and Imaging Technology, Tbingen, Germany
3Medical University Innsbruck, Department of Cardiology, Innsbruck, Austria
4University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Sustained increase of cardiac workload is known to trigger cardiac remodeling with eventual development of cardiac failure. Compelling evidence points to a critical role of enhanced cardiac Na+/H+ exchanger (NHE1) activity in the underlying pathophysiology. The signaling triggering up-regulation of NHE1 remained, however, ill defined. The present study explored the involvement of the serum- and glucocorticoid-inducible kinase Sgk1 in cardiac remodeling due to transverse aortic constriction (TAC). To this end, experiments were performed in gene targeted mice lacking functional Sgk1 (sgk1-/-) and their wild type controls (sgk1+/+). Transcript levels have been determined by RT-PCR, cytosolic pH (pHi) utilizing 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fluorescence, Na+/H+ exchanger activity by the Na+ dependent realkalinization after an ammonium pulse, ejection fraction (%) utilizing cardiac cine magnetic resonance imaging and cardiac glucose uptake by PET imaging. As a result, TAC increased the mRNA expression of Sgk1 in sgk1+/+ mice, paralleled by an increase in Nhe1 transcript levels as well as Na+/H+ exchanger activity, all effects virtually abrogated in sgk1-/- mice. In sgk1+/+mice, TAC induced a decrease in Pgc1a mRNA expression, while Spp1 mRNA expression was increased, both effects diminished in the sgk1-/- mice. TAC was followed by a significant increase of heart and lung weight in sgk1+/+ mice, an effect significantly blunted in sgk1-/- mice. TAC increased the transcript levels of Anp and Bnp, effects again significantly blunted in sgk1-/- mice. TAC increased transcript levels of Collagen I and III as well as Ctgf mRNA and CTGF protein abundance, effects significantly blunted in sgk1-/- mice. TAC further decreased the ejection fraction in sgk1+/+ mice, an effect again attenuated in sgk1-/- mice. Also, cardiac FDG-Glucose uptake after TAC was increased to a larger extent in sgk1+/+ mice than sgk1-/- mice. These observations point to an important role for SGK1 in cardiac remodeling and development of heart failure following an excessive work load.

To cite this abstract, please use the following information:
Acta Physiologica 2012; Volume 204, Supplement 689 :O6

Our site uses cookies to improve your experience.You can find out more about our use of cookies in our standard cookie policy, including instructions on how to reject and delete cookies if you wish to do so.

By continuing to browse this site you agree to us using cookies as described in our standard cookie policy .

CLOSE