Myocardial remodeling in chronic pressure or volume overload in the rat heart

Author(s)

Luiz Shiguero Matsubara ^[1] ; Silvia Narikawa ^[2] ; Ana Lucia dos Anjos Ferreira ^[3] ; Sergio Alberto Rupp de Paiva ^[4] ; Leonardo Mamede Zornoff ^[5] ; Beatriz Bojikian Matsubara ^[6]

Affiliation

^[1] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

^[2] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

^[3] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

^[4] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

^[5] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

^[6] Unesp. Faculdade de Medicina de Botucatu. Departamento de Clínica Médica

• Document type: Journal article
• Source: Arquivos Brasileiros de Cardiologia; v. 86, n. 2, p. 126-130, 2006-02-00.

Abstract

OBJECTIVE: To compare cardiac structural changes in experimental pressure and volume overload models. METHODS: The study analysis included renovascular hypertensive rats (RVH, n=8), normotensive rats with volume overload caused by an aortocaval fistula (ACF, n=10) and control rats (CONT, n=8). After four weeks, tail cuff blood pressure (SBP) was recorded. Rats were killed, the hearts were excised and the right and left ventricles (RV&LV) were weighed (RVW&LVW). Using histological sections, myocyte cross sectional areas (MA). LV wall thickness (LVWT) LV cavity diameter (LVD), normalized LVWT (LVWT/LVD) and collagen volume fraction (CVF) were measured. The comparisons were made using the ANOVA and Tukey test for a significance level of 5%. RESULTS: Tail cuff blood pressure (mmHg) was higher in the RVH group (RVH = 187 ± 22; CONT = 125 ± 10; ACF = 122 ± 6, p<0.05). LV hypertrophy was observed in the RVH and ACF groups. The ACF group presented a significant increase in size of LVD, compared to CONT and RVH. The absolute and normalized ventricular wall thickness were similar among the groups. The RVH group presented a significant increase in CVF compared to CONT group and ACF group. CONCLUSION: Cardiac remodeling patterns following volume or pressure overload are distinct, suggesting that their implications on ventricular dysfunction are not interchangeable. (AU)