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Updated: Nov 16, 2025
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A Rat Model of Pressure Overload Induced Moderate Remodeling and Systolic Dysfunction as Opposed to Overt Systolic Heart Failure
Published on: April 30, 2020
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Calcium homeostasis behavior and cardiac function on left ventricular remodeling by pressure overload
I F S Mazeto1, K Okoshi2, C F S M P Silveira2
1Departamento de Infectologia, Dermatologia, Diagnóstico por Imagem e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil.
Summary
Pressure overload from aortic stenosis impairs heart function by altering calcium handling proteins, specifically decreasing Na+/Ca2+ exchanger (NCX1) and SERCA2a, leading to diastolic dysfunction.
Area of Science:
- Cardiology
- Molecular Biology
- Physiology
Background:
- Cardiac calcium (Ca2+) homeostasis is crucial for heart function.
- Sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) and sarcolemmal Na+/Ca2+ exchanger (NCX1) are key regulators of Ca2+ handling.
- Previous research indicates altered SERCA2a and NCX1 function in heart failure.
Purpose of the Study:
- To investigate the impact of pressure overload on heart function.
- To evaluate the behavior of Ca2+-handling proteins in hypertrophied heart muscle.
- To assess changes in SERCA2a and NCX1 under pressure overload conditions.
Main Methods:
- Aortic stenosis (AoS) model in Wistar rats (n=20) compared to Sham controls.
- Echocardiography for cardiac function and structure assessment.
- Isolated papillary muscle (IPM) analysis for myocardial function and Ca2+ handling.
- Western blot (WB) for Ca2+-handling protein expression (NCX1, SERCA2a, PLB).
Main Results:
- AoS induced concentric hypertrophy with preserved ejection fraction but diastolic dysfunction (dilated left atrium, increased wall thickness).
- IPM studies revealed increased resting tension (stiffness) and altered Ca2+ handling in AoS rats.
- WB showed decreased expression of NCX1, SERCA2a, and phosphorylated phospholambam (PLB) on serine-16 in the AoS group.
Conclusions:
- Aortic stenosis leads to left ventricular hypertrophy and diastolic dysfunction.
- Impaired cardiac function in AoS is associated with deficits in NCX1, SERCA2a, and phosphorylated PLB.
- These findings highlight the critical role of Ca2+ handling protein dysregulation in pressure-induced heart disease.
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