Effects of aerobic exercise training on vascular responsiveness of femoral artery from rats fed with high-fat diet

Author(s)

Amanda Christine da Silva Sponton

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2016-02-22

Examining board members

Maria Andréia Delbin; Dora Maria Grassi Kassisse; Angelina Zanesco

• Advisor: Maria Andréia Delbin

Abstract

Physical inactivity and obesity are considered important risk factors in the genesis of cardiovascular disease. However, few studies investigated the effects of exercise training in endothelial function of femoral artery aiming to research the peripheral artery disease in animal models of obesity. In the present study we aim to investigate the effects of aerobic exercise training on vascular response of femoral artery from rats fed with high-fat diet. Male Wistar rats (290-320g) were divided into four groups: control sedentary (c-SD, n=20), control trained (c-TR, n=20), high-fat diet sedentary (dh-SD, n=20) and high-fat diet trained (dh-TR, n=20). For sixteen weeks, animals from c-SD and c-TR groups were fed with standard chow (Nuvilab CR1), and dh-SD and dh-TR groups were fed with high-fat diet. After eight weeks, c-TR and dh-TR groups initiated the aerobic exercise training on treadmill, 5 days/week, 60 min/session (10 min at 40% of maximum speed, 40 min at 50-60% of maximum speed, and 10 min at 40% of maximum speed) and 0% grade until the end of the protocol. Concentration-response curves to: acetylcholine (Ach), sodium nitroprusside (SNP), phenylephrine (PHE) and the thromboxane A2 analogue (U46619) were obtained in femoral artery. Vascular protein expression of: eNOS, adiponectin receptor (AdipoR), leptin receptor (ObR), and superoxide dismutase isoforms (Cu/Zn-SOD, Mn-SOD and EC-SOD) were determined, as well as, the nitric oxide (NO) production and reactive oxygen species (ROS) generation. Biochemical parameters were analyzed: glucose, total cholesterol, triglycerides, insulin, leptin, adiponectin, TNF-?, MCP-1 and PAI-1. The animals from dh-SD group had a significantly increase in body weight (652±16g), epididymal fat (23±2g), triglyceride (233±11mg/dl), insulin (6±1ng/ml), leptin (9±1ng/ml), TNF-? (0.4±0.04pg/ml), MCP-1 (138±23pg/ml) and PAI-1 (120±23pg/ml), when compared with c-SD group (547±12g; 8±1g; 104±9mg/dl; 3±1ng/ml; 4±0.5ng/ml; 0.2±0.02pg/ml; 48±12pg/ml; and 23±9pg/ml, respectively). Exercise training was effective in to reduce all these alterations in the dh-TR group (549±11g; 14±1g; 96±10mg/dl; 3±0.5ng/ml; 5±1ng/ml; 0.2±0.02pg/ml; 53±11pg/ml; and 65±9pg/ml, respectively). Blood glucose values were reduced in trained groups (c-TR: 81±3mg/dl; dh-TR: 88±3ng/ml) when compared with sedentary groups (c-SD: 92±2mg/dl; dh-SD: 100±3ng/ml). No differences were seen in total cholesterol and adiponectin concentrations in all groups. The maximal response (EMAX) to Ach was reduced in dh-SD (60±4%) compared with c-SD (77±2%), and the exercise training normalized this response in the dh-TR group (74±1%) without changing in the potency (pEC50). No changes to SNP, PHE and U46619 were observed. Decreased protein expressions of eNOS, Cu/Zn-SOD and ObR were observed in dh-SD group when compared with c-SD, associated with reduced NO production and increased EROs generation. The exercise training normalized these alterations in dh-TR group. The protein expressions of AdipoR, Mn-SOD and EC-SOD were not modified. In conclusion, the aerobic exercise training for eight weeks improved the endothelium-dependent relaxation in femoral artery from rats fed high fat-diet. This response was associated with increased vascular NO production/bioavailability and decreased ROS generation, as well as, reduction in systemic inflammatory biomarkers (AU)

• FAPESP's process: 13/26866-4 - Effects of aerobic exercise training on vascular response of femoral artery from rats fed with high-fat diet
• Grantee: Amanda Christine da Silva Sponton
• Support Opportunities: Scholarships in Brazil - Master