Silencing of the Na/H exchanger 1(NHE-1) prevents cardiac structural and functional remodeling induced by angiotensin II.

Chronic activation of the renin angiotensin system (RAS) favors several cardiac diseases, among which myocardial hypertrophy occupies an outstanding place. In this context, the hyperactivity of the cardiac Na/H (NHE-1) exchanger plays a key role. The pathologic remodeling of the myocardium constitutes an independent risk factor for morbidity and mortality with continuously increasing healthcare cost.

Carbonic anhydrase inhibitors reduce cardiac dysfunction after sustained coronary artery ligation in rats.

Background: Two potent carbonic anhydrase (CA) inhibitors with widely differing membrane permeability, poorly diffusible benzolamide (BZ), and highly diffusible ethoxzolamide (ETZ) were assessed to determine whether they can reduce cardiac dysfunction in rats subjected to coronary artery ligation (CAL)-induced myocardial infarction.

Methods And Results: Rats with evidence of heart failure (HF) at 32 weeks following a permanent left anterior coronary artery occlusion were treated with placebo, BZ, or ETZ (4 mg kgday) for 4 weeks at which time left ventricular function and structure were evaluated. Lung weight/body weight (LW/BW) ratio increased in CAL rats by 17±1% vs.

Activated macrophages as a feeder layer for growth of resident cardiac progenitor cells.

The adult heart contains a population of cardiac progenitor cells (CPCs). Growing and collecting an adequate number of CPCs demands complex culture media containing growth factors. Since activated macrophages secrete many growth factors, we investigated if activated isolated heart cells seeded on a feeder layer of activated peritoneal macrophages (PM) could result in CPCs and if these, in turn, could exert cardioprotection in rats with myocardial infarction (MI).

Gender differences in cardiac left ventricular mass and function: Clinical and experimental observations.

Background: The aim of this study was to evaluate gender-associated impact on left ventricular mass (LVM) and on left ventricular function (LVF) in humans and rats with aging.

Methods: Myocyte area and collagen volume fraction (CVF) were studied in rats. LVM and LVF were evaluated in animals and humans by echocardiography and LVM index (LVMI) was obtained.

Sex-related difference in left ventricular mass in nonhypertensive young adults: role of arterial pressure.

Background: Blood pressure (BP) is higher in men than in women at similar ages through adult life. Interestingly, a similar pattern is detected in left ventricular mass (LVM), classically attributed to differences in body size. However, the existing difference in BP between sexes might be relevant in determining LVM and it has been not fully investigated.

[Echocardiographic study of left ventricular geometry in spontaneously hypertensive rats].

The purpose of this study was to analyze by echocardiogram left ventricular (LV) geometry in spontaneously hypertensive rats (SHR). Echocardiographic study, systolic blood pressure and heart rate were obtained in 114 male, 4-month old rats, 73 SHR and 41 Wistar (W). Left ventricular mass index (LVMI), relative wall thickness (RWT), stroke volume, and mid ventricular shortening were calculated with echocardiographic parameters.

Endurance training in the spontaneously hypertensive rat: conversion of pathological into physiological cardiac hypertrophy.

The effect of endurance training (swimming 90 min/d for 5 days a week for 60 days) on cardiac hypertrophy was investigated in the spontaneously hypertensive rat (SHR). Sedentary SHRs (SHR-Cs) and normotensive Wistar rats were used as controls. Exercise training enhanced myocardial hypertrophy assessed by left ventricular weight/tibial length (228+/-7 versus 251+/-5 mg/cm in SHR-Cs and exercised SHRs [SHR-Es], respectively).

[Paradigms and paradoxes of left ventricular hypertrophy: from the research laboratory to the clinical consultation].

Cardiac hypertrophy can occur as an adaptative response to increased cardiac workload. Different types of cardiac hypertrophy arise from a combination of genetic, physiologic, and environmental factors. When hypertophic growth of the heart leads to left ventricular dysfunction and heart failure, the response is considered as maladaptive or pathological hypertrophy.

[Echocardiographic analysis of the effect of different Na+/H+ exchanger inhibitors on left ventricular structure and function in spontaneously hypertensive rats].

The aim of this study was to analyze by echocardiogram, the action of two Na+/H+ exchange, inhibitors, HOE 642 (HOE) and BIIB 723 (BIIB) on left ventricular (LV) mass and LV systolic function. We studied 16 spontaneously hypertensive rats (SHR), 8 treated with HOE 30 mg/kg/day, 8 with 30 mg/kg/day of BIIB during 30 days and 4 SHR as controls during those 30 days. Results are expressed as mean values +/- SEM.