CHRONIC EFFECTS OF SUCROSE INGESTION ON METABOLIC AND HEMODYNAMIC PARAMETERS IN RATS

Abstract

There is a relationship between sucrose feeding and arterial hypertension. The objective of this study was to investigate, in rats with overload of sucrose in diet, the effect on cardiac output (CO) and total peripheral resistance (TPR). The effects of sucrose on sympathetic nervous system (SS) and renin-angiotensin system (RAS) were also evaluated. Wistar rats (150–220g) were treated for 30 days with sucrose solution (20%) instead of drink water (SC; n=10), the control group (C; n=9) had tap water ad libitum. Mean arterial pressure (MAP), CO and TPR were “on line” recorded in a Cardiomax system. The effects of sympathetic and angiotensinergic system blockade on hemodynamics parameters were evaluated by hexamethonium and captopril administration, respectively. Circulating levels of angiotensin I and II were determined by HPLC. An increase in MAP was observed in SC (128±1mmHg) compared with C (102±4 mmHg) meditated by a TPR increase (SC 1,39±0,03 and, C 0,93±0,11 mmHg/mL/min). The sympathetic blockade caused a larger fall in MAP in C (from 102±4 to 51±0,5 mmHg) than in SC (from 128±1 to 75±1 mmHg). However, the depressor response to captopril was larger in SC (from 97±2 to 58±2 mmHg) than in C (from 80±2 to 68±2 mmHg). There was a reduction in circulating AngioI levels in SC (80±10 ng/mL) in relation to C (193±27 ng/mL). However, AngioII was higher in SC (421±41 ng/mL) compared with C (302±10 ng/mL). Taken altogether, the results show that an overload of sucrose in the diet caused increase in MAP due to TPR. The hypertension was related to an increase in circulating AngioII. Supported by FAPESP; CNPq (PRONEX).