Aerobic exercise training prevents kidney lipid deposition in mice fed a cafeteria diet.

AIM: The objective of this study was to investigate the potential of aerobic exercise training (AET) to prevent kidney lipid accumulation and the contribution of renal metabolism to mediate this response. MAIN METHODS: Male C57BL/6J mice were assigned into groups CHOW-SED (chow diet, sedentary; n = 13), CHOW-TR (chow diet, trained; n = 13), CAF-SED (cafeteria diet, sedentary; n = 13) and CAF-TR (cafeteria diet, trained; n = 13). AET consisted in running sessions of 60 min at 60% of maximal speed conducted five days per week for eight weeks. KEY FINDINGS: AET prevented weight gain in both trained groups. Food intake was not different among groups, however water intake, urine output, urine potassium and osmolarity were reduced in CAF-SED and CAF-TR groups. Kidney lipid deposition increased in CAF-SED (4.12 ±â€¯0.5%/area) compared with CHOW-SED (1.7 ±â€¯0.54%/area), and the AET prevented this increase in the CAF-TR group (2.1 ±â€¯0.5%/area). The Bowman's capsule area decreased in CAF-SED and CAF-TR groups while the Bowman' space reduced in CAF-SED compared to CHOW-SED group, which was prevented by AET in the CAF-TF group. We observed a 27% increase in the p-AMPK expression in CAF-TR compared to CHOW-SED group without differences in the SIRT-1, PGC1-α, ACC and p-ACC. ß-HAD activity increased in CAF-SED (43.9 ±â€¯4.57 nmol·min-1·ug-1) and CAF-TR (44.7 ±â€¯2.6 nmol·min-1·ug-1) groups compared to CHOW-SED (35.1 ±â€¯2.9 nmol·min-1·ug-1) e CHOW-TR (36.6 ±â€¯2.7 nmol·min-1·ug-1). SIGNIFICANCE: AET prevented kidney lipid accumulation induced by cafeteria diet and this response was not associated with changes in the renal metabolic activity that favors lipid oxidation.

Exposure to high-fat diet since post-weaning induces cardiometabolic damage in adult rats.

AIMS: This study sought to investigate the metabolic, hemodynamic and autonomic responses in adult rats exposed to high-fat diet since post-weaning. MAIN METHODS: Young male Wistar rats were assigned into groups fed with standard normal diet (3% lipids; ND, n=8) or high-fat diet (30% lipids; HD, n=8) during 8weeks. Body composition, food intake, serum triglycerides, total cholesterol, insulin, leptin and adiponectin concentrations were determined. Hemodynamic and autonomic evaluations were performed. Renin angiotensin system and nitric oxide were also studied by pharmacological blockades. KEY FINDINGS: HD group showed no difference in body weight, total cholesterol, food intake in calories and insulin concentration, but visceral fat pads weight, triglycerides and leptin were higher in HD group. Moreover, HD group decreased adiponectin level, increased 12% of mean arterial pressure (MAP) and 6% of heart rate compared with ND group. Spectral analyses showed an increase in cardiovascular sympathetic modulation in HD compared with ND group. Depressor responses after losartan were higher in HD compared with ND group: -9±0.7 vs.-3±1.6mmHg. Pressor responses after l-NAME were higher in HD compared with ND: 45±8 vs. 32±5mmHg. SIGNIFICANCE: High-fat diet consumption during early period of life can increase WAT mass and MAP. These alterations may be mediated by an augment in sympathetic activity associated with higher leptin and lower adiponectin levels. These cardiometabolic damages can lead to the development of hypertension and increase cardiovascular risk in adulthood.

Early developmental exposure to high fructose intake in rats with NaCl stimulation causes cardiac damage.

PURPOSE: Metabolic syndrome (MS) increases the risk of type 2 diabetes and cardiovascular disease. High consumption of fructose is a proposed cause of increased MS, manifested through hypertension, obesity, insulin resistance, and dyslipidemia. High NaCl also increases the risk of CD. The purpose of this study is to evaluate the influence of fructose and sodium on autonomic dysfunction and its relation with CD in MS. Fructose overload was started at weaning and continued through adulthood. METHODS: Male Wistar rats (21 days) were divided into four groups: Control (C), fructose consumption (10%, F), NaCl consumption (salt 1% for the 10 last days, S), and fructose and NaCl (FS), and monitored for 8 weeks. Metabolic evaluations consisted of Lee index, glycemia, insulin and glucose tolerance tests, triglycerides, and total cholesterol measurements. Cardiovascular parameters measured were arterial pressure (AP) and cardiac function performed by echocardiography. They also measured the influence of renin angiotensin (RAS) and autonomic nervous systems by drug blockage with losartan, atropine, and atenolol. RESULTS: Energy analysis showed no change between groups. Fructose overload induced a MS state, confirmed by insulin resistance, glucose intolerance, and dyslipidemia. Fasting glucose was increased in F and FS rat groups compared with C and S groups. AP was higher in F, S, and FS groups in comparison with the C group. The hypotensive response after sympathetic blockade was increased in F, S, and FS versus C. The cardiac vagal tonus was reduced in F and FS animal groups. The intrinsic heart rate was decreased in the FS group (372 ± 9 bpm) compared with the C group (410 ± 13 bpm). The morphometric measurements evaluated through left ventricular diameter during diastole and the left ventricular diameter during systole decreased in the FS group (16 and 26%, respectively). Diastolic function was reduced in F and FS. The depressor response induced by losartan was increased in the F group in comparison with other groups. However, there was a uniform increase in plasma ACE activity in all treated groups compared with the C group. CONCLUSIONS: Data suggest that early exposure to high fructose intake produced marked alterations in metabolic and cardiovascular function. When stimulated by NaCl, the fructose-fed subjects showed further impairment in cardiac function.

Effect of carotid and aortic baroreceptors on cardiopulmonary reflex: the role of autonomic function.

We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups: control (CG, N = 8), aortic denervation (AG, N = 5) and carotid denervation (CAG, N = 9). AG animals presented increased arterial pressure (12%) and HR (11%) compared with CG, while CAG animals presented a reduction in arterial pressure (16%) and unchanged HR compared with CG. The sequential blockade of autonomic effects by atropine and propranolol indicated a reduction in vagal function in CAG (a 50 and 62% reduction in vagal effect and tonus, respectively) while AG showed an increase of more than 100% in sympathetic control of HR. The Bezold-Jarish reflex was evaluated using serotonin, which induced increased bradycardia and hypotension in AG and CAG, suggesting that the sensitivity of the cardiopulmonary reflex is augmented after selective denervation. Atropine administration abolished the bradycardic responses induced by serotonin in all groups; however, the hypotensive response was still increased in AG. Although the responses after atropine were lower than the responses before the drug, indicating a reduction in vagal outflow after selective denervation, our data suggest that both denervation procedures are associated with an increase in sympathetic modulation of the vessels, indicating that the sensitivity of the cardiopulmonary receptors was modulated by baroreceptor fibers.

Effect of carotid and aortic baroreceptors on cardiopulmonary reflex: the role of autonomic function

We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups: control (CG, N = 8), aortic denervation (AG, N = 5) and carotid denervation (CAG, N = 9). AG animals presented increased arterial pressure (12 percent) and HR (11 percent) compared with CG, while CAG animals presented a reduction in arterial pressure (16 percent) and unchanged HR compared with CG. The sequential blockade of autonomic effects by atropine and propranolol indicated a reduction in vagal function in CAG (a 50 and 62 percent reduction in vagal effect and tonus, respectively) while AG showed an increase of more than 100 percent in sympathetic control of HR. The Bezold-Jarish reflex was evaluated using serotonin, which induced increased bradycardia and hypotension in AG and CAG, suggesting that the sensitivity of the cardiopulmonary reflex is augmented after selective denervation. Atropine administration abolished the bradycardic responses induced by serotonin in all groups; however, the hypotensive response was still increased in AG. Although the responses after atropine were lower than the responses before the drug, indicating a reduction in vagal outflow after selective denervation, our data suggest that both denervation procedures are associated with an increase in sympathetic modulation of the vessels, indicating that the sensitivity of the cardiopulmonary receptors was modulated by baroreceptor fibers.

Paraquat resistance and starvation conditions in the selection of longevity extremes in Drosophila melanogaster populations previously selected for long and short developmental period.

This paper analyzes the interaction between resistance to free radicals, development under starvation conditions, sex, and its consequences to the lifespan of Drosophila melanogaster populations selected for developmental time and longevity. Our data suggest that the interaction between these physiological and environmental parameters is modulated largely by the pre-imaginal developmental time, since the response to selection for longevity extremes depends strongly on the previous selection for developmental time extremes.