Efeitos da dieta básica regional hiperssódica sobre parâmetros hemodinâmicos, autonômicos cardíacos e bioquímicos em ratos em diferentes fases do desenvolvimento

by Oliveira Soares, Fernanda de

Abstract (Summary)
The aim of this study was to investigate the effects of malnutrition on heart autonomic control, lipid and serum eletrolyte levels in male Wistar rats fed two types of diet: Standard Labina (normal sodium 0.36g%) and Regional Basic Diet high sodium (RBDh, sodium 0.95%) with a protein content of 23% and 8%, respectively. The animals were divided into three groups: A Control group (CG) fed on Labina diet at all stages of development; a RBDn Nursing group (RBDhN)in which the dams received RDBn until the young were weaned, and thereafter the offspring received Labina diet; a RBDh After Nursing group (RBDhAN), in which the dams was fed Labina diet at all stages of pregnancy and nursing andthe offspring were given RBDh after nursing until adulthood. Vascular catheters were implanted in the femoral vein for drug infusion, and in the femoral artery to record systolic arterial pressure (SAP) and diastolic arterial pressure (DAP). The heart rate (HR) was determined from the SAP. Vagal and sympathetic activities were blocked with methylatropine (A) and propranolol (P) administered in this order and in reverse. The intrinsic HR was evaluated after simultaneous blockade with A and P. Venous blood samples were collected for lipid measurements (total cholesterol and triglyceride fractions) and estimations made of serum eletrolyte levels (sodium, potassium, chloride, calcium, bicarbonate).Significant differences were determined by one-way analysis of variance followed by Tukey and by Dunn test (pamp;#8804;0.05). Weight was significantly reduced in the RBDhN and RBDhAN groups (pamp;#8804;0.05) when compared with the CG rats. However, the RBDhN group displayed a rate of weight gain similar to that observed in the CG rats, while in the RDBhAN group it was significantly lower until adulthood. Baseline mean arterial pressure (MAP), SAP, DAP and HR were found to be increased only in the RBDhAN group (pamp;#8804;0.01) when compared with the CG rats. In this group, the cardiac sympathetic activity was also raised, as evidenced by an increase in both tone (pamp;#8804;0.01) and sympathetic effect (pamp;#8804;0.05). On the other hand, the vagal activitity was found to be reduced, with diminished tone (pamp;#8804;0.05) and vagal effect on the heart (pamp;#8804;0.01) compared to the CG rats. No changes in the hemodynamic parameters were found in the RBDhN group (pamp;#8804;0.05), except for an increase in sympathetic tone (pamp;#8804;0.05). The intrinsic HR did not suffer significant alterations in the group of animals receiving a malnourished diet when compared to the CG group. With regards to blood lipid, only the RBDhAN group showed an increase in cholesterol and low density lipoproteins (pamp;#8804;0.01) in relation to the CG and RBDhN groups (pamp;#8804;0.05). These results indicate that malutrition associated with high dietary sodium levels produced significant hemodynamic, lipid and electrolytic changes when the diet was administered for a prolonged period during growth
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Ana Maria Santos Cabral

School:Universidade Federal de Pernambuco

School Location:Brazil

Source Type:Master's Thesis

Keywords:perfis lipídico e eletrolítico ? análise bioquímica experimentos em ratos dieta básica hiperssódica freqüência cardíaca pressão arterial atividade autonômica fisiologia farmacologia aspectos nutricionais fases de desenvolvimento aleitamento pósdesmame


Date of Publication:09/04/2006

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