Effects of concurrent training on irisin and fibronectin type-III domain containing 5 (FNDC5) expression in visceral adipose tissue in type-2 diabetic rats.

CONTEXT: Evidence suggests that myokines could have clinical implications for metabolic diseases such as type-2 diabetes. OBJECTIVE: We investigated the effects of concurrent training (CT) on irisin and fibronectin type-III domain containing five (FNDC5) expressions in visceral adipose tissue (VAT) in type-2 diabetic rats. MATERIALS AND METHODS: Eighteen male Wistar rats (ages four to eight weeks) became diabetic using nicotinamide and streptozotocin and were assigned to either a control (CON) or a CT group using a randomised block design. The CT group exercised on a motor-driven treadmill at 60 to 75 per cent of VO2max (0% grade) for 10-40 min/day (aerobic training) and performed 10 climbs on a 1-meter ladder utilising weighted resistance of 30-100% of body mass (resistance exercise) for 5 days/week over 8 weeks. Forty-eight hours after the last training session, the VAT of rats was removed and washed. FNDC5-relative gene expression and irisin were measured by the reverse transcription polymerase chain reaction (RT-PCR) method and enzyme-linked immunosorbent assay (ELISA) kit. Additionally, insulin resistance and plasma insulin and glucose levels were determined. RESULTS: Our findings revealed that CT significantly increased FNDC5-relative gene expression in the VAT of type-2 diabetic rats compared to controls. Furthermore, eight weeks of CT improved insulin resistance and insulin and glucose levels but did not significantly alter irisin levels in type-2 diabetic rats. DISCUSSION AND CONCLUSION: The results of this study demonstrated that CT increased FNDC5 mRNA and improved insulin resistance, insulin, and glucose levels. Also observed were increased trends (non-significant, p = .051) in irisin levels. Hence, CT may play a role in attenuating metabolic disorders such as obesity and type-2 diabetes.

Effects of L-citrulline supplementation on nitric oxide and antioxidant markers after high-intensity interval exercise in young men: a randomized controlled trial.

L-citrulline (L-Cit) is a nonessential amino acid that stimulates nitric oxide (NO) production and improves exercise performance by reducing muscle damage indices; however, the direct benefits of L-Cit on antioxidant markers are unclear. The aim of this study was to examine antioxidant responses to high-intensity interval exercise following acute L-Cit supplementation. Nine young men (21 ± 1 years) participated in a double-blind crossover study in which they received 12 g of L-Cit and placebo (PL) an hour prior to high-intensity interval exercise on two occasions, separated by a seven-day washout period. Blood samples were obtained before (PRE), immediately after (IP), 10 (10P), and 30 min after exercise (30P) from the cubital vein using standard procedures. Serum concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and NO metabolites (NOx) were measured. The exercise protocol significantly elevated SOD (p = 0.01) and GPx (p = 0.048) from PRE to 10P in the L-Cit group with greater changes than the PL group. CAT concentrations increased IP (p = 0.014) and remained elevated at 10P (p = 0.03) and 30P (p = 0.015) in both the L-Cit and PL conditions. NOx concentrations increased IP (p = 0.05) in the L-Cit group with greater changes than PL group in PRE to IP, PRE to 10P, and PRE to 30P (p < 0.05). Our data indicate that L-Cit supplementation (single 12 g dose pre-exercise) induces improvements in antioxidant markers following a session of high-intensity interval exercise in young men.

Recovery of sphalerite from a high zinc grade tailing.

In this work, the flotation recovery of sphalerite and pyrite from an old high zinc grade tailing was studied. In particular, the effect of different flotation reagents such as collector, auxiliary collector, depressant, activators, and frother on the flotation performance were investigated. The synergic effect of the collector blends, as well as frother blends were also studied. In addition, the effect of the pre-conditioning of flotation pulp with scrubbing or ultrasonic on the selective separation of sphalerite and pyrite minerals were studied. More than 73% of the sphalerite was recovered from the accumulated tailings in the rougher stage. The pulp viscosity was considerably increased by increasing the pH from 5.5 to 10.5. As a result, sphalerite recovery and Zn selective separation were both considerably dropped. It was also found that frothers (MIBC and A65) have a synergic effect, and their mixture showed better metallurgical results than when each frother were solely used. The pre-conditioning with scrubbing or ultrasonic resulted in a major increase in the sphalerite floatability.

The effects of pumpkin seed oil supplementation on arterial hemodynamics, stiffness and cardiac autonomic function in postmenopausal women.

BACKGROUND: Postmenopausal women have a higher prevalence of hypertension than age-match men. Evidence from animal studies have demonstrated the antihypertensive effects of pumpkin seed oil (PSO). We examined the effects of PSO supplementation on vascular function and heart rate variability (HRV) in postmenopausal women with elevated blood pressure (BP). MATERIALS AND METHODS: Participants were randomly assigned to either a PSO (n = 12) or a placebo group (n = 11). Participants in the PSO group consumed 3 g/day of PSO. Brachial and central BP, wave reflection (augmentation index, AIx), arterial stiffness (SI) and various HRV parameters were measured before and after 6 weeks. RESULTS: AIx, brachial and central systolic BP significantly (P < 0.05) decreased following PSO but not after placebo. SI and HRV parameters remained unchanged after PSO or placebo. CONCLUSION: PSO improved arterial hemodynamics in postmenopausal women and therefore might be effective in the prevention and treatment of hypertension in this population. CLINICAL TRIAL ID: (NCT03716960).

Effects of upper-body, lower-body, or combined resistance training on the ratio of follistatin and myostatin in middle-aged men.

PURPOSE: Due to the mechanistic role of myostatin and follistatin in modulating muscle mass, shifts in the follistatin to myostatin ratio (F:M) may help explain changes in muscular size in response to resistance training (RT). The present study examined whether differential responses in follistatin and myostatin occur based on the amount of active musculature in a RT program in middle-aged men. METHODS: Forty middle-aged men (age = 46.5 ± 3.1 years) were randomly assigned to 1 of 4 groups, upper-body RT (UB; n = 10), lower-body RT (LB; n = 10), combined RT (UB + LB; n = 10) or control (C; n = 10). The training protocol consisted of three exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 h after the final session of the training program. RESULTS: Muscle mass significantly increased (p < 0.05) following UB = 0.76 ± 0.46 kg, LB = 0.90 ± 0.29 kg, UB + LB = 1.38 ± 0.70 kg, compared to no changes after control. Serum follistatin increased in the LB = 0.24 ± 0.06 ng mL-1, UB = 0.27 ± 0.17 ng mL-1, UB + LB = 0.50 ± 0.18 ng mL-1, while serum myostatin decreased in the LB = - 0.11 ± 0.08 ng mL-1 and UB + LB = - 0.34 ± 0.23 ng mL-1, but not UB = 0.07 ± 0.16 ng mL-1. Further, change in concentration following training was larger between UB + LB and either LB or UB alone for both follistatin and myostatin. CONCLUSIONS: Both UB and LB increase muscle mass and alter the F: M ratio; however, the change in these endocrine markers is approximately twice as large if UB and LB is combined. The endocrine response to RT of myostatin and follistatin may depend on the volume of muscle mass activated during training.

The influence of concurrent training intensity on serum irisin and abdominal fat in postmenopausal women.

INTRODUCTION: Menopause seems to be among the factors related to the development of prediabetes and central obesity. Conversely, physical activity may have a major role in reducing metabolic syndrome in women of postmenopausal age. MATERIAL AND METHODS: Forty-eight postmenopausal active and sedentary women within the ages of 45-65 years were randomized to four groups: 1) high-intensity concurrent interval exercise (HCI; n = 15), 2) moderate-intensity continuous concurrent exercise (MCC; n = 14), 3) control daily active (CDA; n = 10), and 4) control sedentary (COS; n = 9). The subjects in the preceding training groups exercised three times per week for 50-65 min/session with high/moderate concurrent exercise for 10 weeks. The levels of serum irisin, insulin sensitivity, abdominal fat distribution (visceral and subcutaneous), and total abdominal fat were measured at baseline and post-test. RESULTS: This study showed that the HCI group had a significantly increased serum irisin (p< 0.001), stimulated favorable alterations in insulin sensitivity status (p = 0.003), and significantly decreased subcutaneous, visceral and, total abdominal fat (p< 0.001). Also, the insulin sensitivity status was significantly increased (p = 0.01) and subcutaneous abdominal fat significantly decreased in the MCC group (p = 0.018). However, this study's results did not find a considerable correlation between insulin sensitivity, irisin level, weight loss and abdominal fat distribution. CONCLUSIONS: High-intensity concurrent exercise has a greater influence on improving most metabolic-related parameters than moderate-intensity concurrent exercise.

Lipocalin-2: Response to a Progressive Treadmill Protocol in Obese and Normal-weight Men.

PURPOSE: Lipocalin-2 (Lcn2), a newer adipocyte-secreted acute phase protein, was recently reported to be correlated with potential effects on obesity and inflammation. The reaction of this protein to progressive exercise has not been evaluated yet. This study was designed to compare the serum Lcn2 and high-sensitivity C-reactive protein (hs-CRP) levels after participating in an acute bout of treadmill protocol in obese and normal-weight men. METHODS: NINE OBESE (AGED: 43.2±4.6 yrs and body mass index (BMI): 31.4±1.6 kg/m(2)) and 9 normal-weight (aged: 42.9±4.4 yrs and BMI: 23.03±1.7 kg/m(2); mean ± SD) sedentary men selected randomly from volunteers performed a single bout of exercise according to the treadmill Bruce protocol. RESULTS: Before the exercise, Lcn2 level was higher in obese than normal-weight individuals (P<0.05). A significant increase in Lcn2, hs-CRP, white blood cells (WBC) and insulin resistance index was observed after the exercise in both groups (P<0.05). The level of Lcn2, hs-CRP and WBC increase was more significant in obese individuals than normal-weight subjects after the exercise (P<0.05). CONCLUSIONS: It seems that the levels of Lcn2 and other inflammatory markers elevated in obese and normal-weight men after participating in an exhaustive progressive exercise. These changes in obese men were considerable.