Background: The purpose of this study was to compare long-term effects of cariporide with those of losartan in postinfarction heart failure.
Methods And Results: Female Sprague-Dawley rats with large myocardial infarctions and sham controls were randomized to losartan, cariporide, or placebo after 7 days and treated for 49 days. Cardiac function was assessed by echocardiography and measurement of left ventricular pressures, and gene expression was assessed by competitive reverse transcription-polymerase chain reaction. Cell dimensions, shortening, and relaxation were determined by videomicroscopy and calcium transients by fura 2. Losartan reduced postinfarction systolic and diastolic left ventricular dilation (by 24% and 31%, respectively), left and right ventricular weight (by 22% and 26%, respectively), and cardiomyocyte hypertrophy length and width (by 62% and 54%, respectively). Induction of myocardial atrial natriuretic peptide decreased 66%. Cariporide did not affect postinfarction hypertrophy or atrial natriuretic peptide. Losartan and cariporide respectively improved reduced cellular contractility (55% and 30%) and reduced elevated systolic (86% and 27%) and diastolic (49% and 43%) calcium. Losartan and cariporide respectively reduced prolonged time to 50% relaxation (66% and 25%) and time to 50% calcium reduction (55% and 53%).
Conclusions: Losartan and cariporide improve cardiomyocyte contractility and calcium regulation in chronic heart failure. Losartan has salutary effects on postinfarction remodeling and gene expression, whereas cariporide is neutral.
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http://dx.doi.org/10.1161/hc1102.105258 | DOI Listing |
Pflugers Arch
September 2014
Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120 S/N, La Plata, 1900, Argentina,
Emerging evidence supports a key role for endothelin-1 (ET-1) and the transactivation of the epidermal growth factor receptor (EGFR) in angiotensin II (Ang II) action. We aim to determine the potential role played by endogenous ET-1, EGFR transactivation and redox-dependent sodium hydrogen exchanger-1 (NHE-1) activation in the hypertrophic response to Ang II of cardiac myocytes. Electrically paced adult cat cardiomyocytes were placed in culture and stimulated with 1 nmol l(-1) Ang II or 5 nmol l(-1) ET-1.
View Article and Find Full Text PDFJ Appl Physiol (1985)
April 2009
Fellow of Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
Na(+)/H(+) exchanger (NHE-1) inhibition was demonstrated to induce the regression of cardiac hypertrophy (CH) in several experimental models and to inhibit mitochondrial death pathway in "in-vitro" experiments. Since recent reports show that NHE-1 inhibition delays the transition from CH to failure, and apoptosis plays a key role in this process, we investigated the effect of chronic treatment with the NHE-1 blocker cariporide on CH and apoptosis in the SHR. One month of cariporide treatment (30 mg x kg(-1) x day(-1)) induced the regression of CH (cardiomyocyte cross-sectional area: 468 +/- 20 vs.
View Article and Find Full Text PDFCardiovasc Res
December 2003
Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina.
Objective: This work was aimed to prove that release/formation of endogenous endothelin acting in an autocrine/paracrine fashion contributes to the increase in contractility promoted by a low dose of angiotensin II.
Methods: Isolated cat papillary muscles were used for force, pH(i), [Na(+)](i) and [Ca(2+)](i) measurements and isolated cat myocytes for patch-clamp experiments.
Results: In papillary muscles, 1.
Pflugers Arch
March 2003
Department of Physiology, University of Sydney F13, Sydney, NSW 2006, Australia.
We examined the possibility that endogenous angiotensin II (AII) is involved in the regulation of the cardiac Na(+)/H(+) exchanger (NHE1) during ischaemia, reperfusion and preconditioning. Mechanical function and intracellular sodium ([Na(+)](i)) were studied in isolated, perfused rat hearts. To test whether AII production might underlie the increased activity of NHE1 on reperfusion, we applied the AII receptor antagonist losartan during ischaemia and reperfusion.
View Article and Find Full Text PDFCirculation
March 2002
Department of Physiology and Biomedical Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
Background: The purpose of this study was to compare long-term effects of cariporide with those of losartan in postinfarction heart failure.
Methods And Results: Female Sprague-Dawley rats with large myocardial infarctions and sham controls were randomized to losartan, cariporide, or placebo after 7 days and treated for 49 days. Cardiac function was assessed by echocardiography and measurement of left ventricular pressures, and gene expression was assessed by competitive reverse transcription-polymerase chain reaction.
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