Structural and functional microvascular alterations in a rat model of metabolic syndrome induced by a high‐fat diet

Abstract

Objective: To investigate microvascular alterations in an experimental model of metabolic syndrome induced by a high-fat diet (HFD) associated with salt supplementation (0.5% NaCl). Design and Methods: Wistar Kyoto rats were fed standard chow (control group, CONT) or HFD for 20 weeks. The functional capillary density (FCD) was assessed using intravital fluorescence videomicroscopy. Results: The HFD group presented a higher systolic blood pressure, plasma glucose and insulin levels, total and LDL-cholesterol levels, triglycerides, and visceral and epididymal fat when compared with the CONT group. When compared with the CONT group, the HFD group showed a lower FCD in the skeletal muscle (P < 0.05) but not in the skin (P > 0.05). The HFD group also had a lower capillary-to-fiber ratio in the skeletal muscle (P < 0.01). The capillary volume density-to-fiber volume density ratio in the left ventricle of the HFD was also reduced (P < 0.01). Finally, rats fed with HFD showed ventricular hypertrophy and increased cardiomyocyte diameter (P < 0.01). Conclusions: The long-term administration of a HFD associated with salt supplementation to rats generates an experimental model of metabolic syndrome characterized by central body fat deposition, insulin resistance, glucose intolerance, hypertriglyceridemia, hypercholesterolemia, arterial hypertension, cardiac remodeling, and rarefaction of the microcirculation in the heart and skeletal muscle.

Associations Between Dietary Patterns and Skin Microcirculation in Healthy Subjects

“…Few studies have investigated the relationships between foods or nutrients and microvascular function, 22,[31][32][33] but none has focused on the possible link of dietary patterns with capillary density and recruitment. In the present study, we investigated a healthy population free of hypertension and insulin Variable with the highest factor loading (>|0.4|) within the component.…”

“…In rodent experimental models, high-fat diets caused a decrease in capillary density. 25,33 In human studies, 15 to 25 g of brazil nuts per day for 16 weeks improved functional microvascular parameters such as red blood cell velocity in female obese subjects, 20 whereas 4 g of docosahexaenoic acid for 6 weeks improved forearm microcirculation in overweight, mildly hyperlipidemic men. 21 Our findings suggest that a dietary pattern of increased consumption of vegetable oils, poultry, and fish and seafood characterized by increased consumption of monounsaturated and polyunsaturated fatty acids and reduced consumption of saturated fatty acids (in the absence of high BP and insulin resistance) might represent an association with higher capillary density, thus less functional and structural capillary rarefaction.…”

Hepatic microvascular dysfunction and increased advanced glycation end products are components of non-alcoholic fatty liver disease

“…The rats (4 weeks of age) were housed in standard cages in a temperature-controlled room (22 ± 1°C) with a 12-h light/dark cycle. The experimental model of NAFLD or MS was induced in 10 animals by 20 weeks of feeding with a high-fat diet administration as previously described by or group [26]. The high-fat diet consisted of a standard rat diet modified containing 30% fat, 56% carbohydrate, and 14% protein (% g) [26].…”

“…The experimental model of NAFLD or MS was induced in 10 animals by 20 weeks of feeding with a high-fat diet administration as previously described by or group [26]. The high-fat diet consisted of a standard rat diet modified containing 30% fat, 56% carbohydrate, and 14% protein (% g) [26]. The main fat source of the high fat diet was saturated fat (lard).…”

Exercise Training Reverses Structural Microvascular Rarefaction and Improves Endothelium-Dependent Microvascular Reactivity in Rats with Diabetes

“…18,21 The CON diet contained 23% protein, 71% carbohydrate, 6% lipid, and 1.3% NaCl (Nuvilab-CR1; Nuvital Nutrients Ltd.), while the HFD contained 14% protein, 56% carbohydrate, 30% lipid, and salt supplementation (standard chow+corn starch+condensed milk+animal fat +0.5% NaCl) as previously described. 22 Saturated fat (lard) was the main fat source in the HFD. After the first week of dietary manipulation, a low dose of STZ (35 mg/kg in 0.5 M citratephosphate buffer, pH 4.5) was injected through the intraperitoneal route in the HFD-fed animals.…”