No abstract

BackgroundExercise stimulates the production of fibronectin type III domain-containing protein 5 (FNDC5), which is cleaved to release a protein called irisin. This protein induces browning of white adipose tissue resulting in increased thermogenesis. Different studies have measured circulating irisin at baseline and in response to exercise among a wide variety of individuals; yet, regarding the effect of different exercise intensities in obese adolescent girls, limited insight is available. This study compares the effect of acute aerobic exercise of moderate intensity and high-intensity interval training (HIIT) on irisin levels in skeletal muscle and plasma of sedentary overweight or obese female adolescents.MethodsThe aerobic group (n = 15) and HIIT group (n = 15) underwent anthropometric and metabolic measurements, electrocardiogram, peak oxygen uptake (VO2peak), and two vastus lateralis muscle biopsies before and after session of workout. The session of aerobic exercise included cycling at 65% of their peak heart rate (HRpeak) for 40 min. In the HIIT group, exercise included six bouts of 1 min at 85–95% HRpeak separated by 1 min of recovery. Irisin levels were evaluated in samples of skeletal muscle (western blot) and plasma (ELISA).ResultsThe levels of expression of irisin in skeletal muscle increased significantly after a session of HIIT (p < 0.05), while aerobic exercise no affect irisin levels. No significant differences between the groups in plasma irisin levels were found.ConclusionsThe increase in muscle irisin levels was observed only following HIIT session. No increases in plasma irisin concentration were observed.

Toluene shows an important genotoxic effect. As the micronuclei test is an effective, fast, simple and low cost biomarker to identify cytogenetic effects, we suggest its utilization as a preventive test of genotoxicity.

Acute renal failure (ARF) in neonates may occur after renal ischemia. Growth factors participate in the tubular regeneration process. Insulin-like growth factor-1 (IGF-1) is produced in the kidney during the recovery phase of ARF. Tumor necrosis factor-alpha (TNFalpha) may play a role in renal apoptosis. We examined serum and urinary IGF-1 and TNFalpha in neonates with or without ARF after asphyxia, in order to assess their possible use as markers of renal damage and recovery. We studied 20 full-term asphyxiated neonates, 10 with ARF and 10 without ARF, and compared them with 13 normal newborns for 7 days after birth. Blood urea, creatinine, pH, base deficit, and serum and urine IGF-1 and TNFalpha were assessed. Neonates with ARF had more-severe acidosis than patients without ARF. All patients had lower serum IGF-1 values immediately after birth than control children. Serum IGF-1 remained low in the ARF patients. The initial urinary IGF-1 was higher in all patients compared with control newborns, and remained elevated for the rest of the study only in the ARF neonates. Serum and urinary TNFalpha concentrations were similar for all healthy and diseased neonates. Measurement of serum and urinary IGF-1 levels in ARF neonates might be of additional value for clinical assessment of ARF.

No abstract