PMID: 9660171Jul 11, 1998Paper

Unchanged sarcoplasmic reticulum Ca2+-ATPase activity, reduced Ca2+ sensitivity, and negative force-frequency relationship in transgenic rats overexpressing the mouse renin gene

Journal of Molecular Medicine : Official Organ of the Gesellschaft Deutscher Naturforscher Und Ärzte
C ZobelR H Schwinger

Abstract

Transgenic rats overexpressing the mouse Ren-2 gene [TG(mREN2)27 rats, TGR] were used to characterize alterations in force generation and relaxation following cardiac hypertrophy. Age-matched Sprague-Dawley rats were used as the control group. The beta-adrenoceptor dependent increase in force of contraction was reduced in the transgenic animals but not the Ca2+-dependent increase in force generation. Additionally, force of contraction decreased after increasing stimulation frequencies (up to 7 Hz), but the frequency-dependent decrease in force of contraction was significantly more pronounced in the transgenic group. The Ca2+ sensitivity in chemically skinned fiber preparations of TGR was reduced than that in Sprague-Dawley rats while maximum effectiveness was the same. Unexpectedly, the sarcoplasmic reticulum Ca2+-ATPase activity measured in crude membrane preparations from TGR did not differ from that in Sprague-Dawley rats; however, the activity of the Na+/K+-ATPase was less while the Na+/Ca2+-exchanger activity was significantly greater. In the same preparations the protein expression of SERCA2 was reduced in TGR while expression of phospholamban and calsequestrin remained the same. Thus in the model of cardiac hypertrophy h...Continue Reading

Citations

Aug 24, 2004·Journal of Molecular Medicine : Official Organ of the Gesellschaft Deutscher Naturforscher Und Ärzte·H DiedrichsR H G Schwinger
Aug 3, 2006·The Journal of Biological Chemistry·Norbert FreyWolfgang M Franz
Oct 26, 2006·European Journal of Applied Physiology·Carsten ZobelRobert H G Schwinger
Apr 10, 2016·American Journal of Physiology. Heart and Circulatory Physiology·Árpád KovácsAttila Tóth
Sep 2, 2006·Experimental Biology and Medicine·Mladen PavlovicSabina Gallati

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