Fig 1.
Timeline representing the experimental design utilized in this study; (B) representative picture of control and high-sucrose treated rats after 24 weeks of treatment.
Table 1.
Somatometric parameters measured in control and high-sucrose diet groups.
Fig 2.
Effect of a 24 week high-sucrose diet in rats evaluated in the shock-probe/burying test.
A significant increase was noticed in the group submitted to a high-sucrose diet in time (%) spent in burying behavior (C) when compared with the control group. No significant effects were elicited on burying behavior latency (A), number of shocks received (B) and the percentage of time spent in freezing behavior (D). Bars represent means ± SEM. Mann-Whitney Test was conducted, *p<0.05. Control group n = 18, high-sucrose diet group n = 17.
Fig 3.
Effect of a 24 week high-sucrose diet on anxiety-like behavior in the elevated plus-maze.
Although not significant, the high-sucrose diet group showed a nonsignificant trend (U = 230, P = 0.053) for a reduced time spent in open arms (A) and a lower percentage of open arms entries (B) when compared with the controls. No effects were observed in the total number of entries into the open+closed arms of the maze (C). Bars represent means ± SEM. Mann-Whitney Test was conducted. Control group n = 27, high-sucrose diet group n = 24.
Fig 4.
Qualitative analysis of the behavior displayed by control and high-sucrose diet groups in the elevated-plus maze.
Fig 5.
Effect of a 24 week high-sucrose diet on anxiety-like behavior as measured in the open-field test.
The high-sucrose diet group exhibited a reduction in the time spent in the central squares (A) and an enhancement in freezing behavior (B) as compared with the control group. Moreover, a decrease of the total distance traveled by the rats within the open-field was observed in the group submitted to the high-sucrose diet (C). Bars represent means ± SEM. Mann-Whitney Test was conducted, **p<0.001. Control group n = 27, high-sucrose diet group n = 24.
Fig 6.
Effect of a 24 week high-sucrose diet on metabolic parameters.
High-sucrose diet rats showed a significant increase in systolic blood pressure (A), without changes in cardiac frequency compared to control rats (B) (n = 26 for high-sucrose and control groups). Moreover, a significant increase in plasma insulin (D) (n = 45 for high-sucrose and control groups), glucose (C) (control group n = 45/high-sucrose diet group n = 50) and triglycerides (E) (control group n = 26/high-sucrose diet group n = 38) levels was observed in the high-sucrose diet group with respect to the controls. Bars represent means ± SEM. Unpaired, two-tailed Student t-test was conducted, *p<0.05, **p<0.01. Control group n = 43, high-sucrose diet group n = 46.
Fig 7.
Effect of a 24 week high-sucrose diet on hormonal traits involved in metabolism and stress.
Plasma leptin (A) and resistin (B) levels in the high-sucrose diet group were significantly elevated compared with the controls (n = 26 control group/high-sucrose diet group n = 38). Plasma corticosterone levels (C) did not show statistical difference between groups (n = 20 control group/high-sucrose diet group n = 18). Bars represent means ± SEM. Unpaired, two-tailed Student t-test was conducted. *p≤0.05.