Effect of Exercise Intensity on Unfolded Protein Response in Skeletal Muscle of Rat

Endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and mitochondrial biogenesis were assessed following varying intensities of exercise training. The animals were randomly assigned to receive either low- (LIT, n=7) or high intensity training (HIT, n=7), or were assigned to a control group (n=7). Over 5 weeks, the animals in the LIT were exercised on a treadmill with a 10degrees incline for 60 min at a speed of 20 m/min group, and in the HIT group at a speed of 34 m/min for 5 days a week. No statistically significant differences were found in the body weight, plasma triglyceride, and total cholesterol levels across the three groups, but fasting glucose and insulin levels were significantly lower in the exercise-trained groups. Additionally, no statistically significant differences were observed in the levels of PERK phosphorylation in skeletal muscles between the three groups. However, compared to the control and LIT groups, the level of BiP was lower in the HIT group. Compared to the control group, the levels of ATF4 in skeletal muscles and CHOP were significantly lower in the HIT group. The HIT group also showed increased PGC-1alpha mRNA expression in comparison with the control group. Furthermore, both of the trained groups showed higher levels of mitochondrial UCP3 than the control group. In summary, we found that a 5-week high-intensity exercise training routine resulted in increased mitochondrial biogenesis and decreased ER stress and apoptotic signaling in the skeletal muscle tissue of rats.

Comparison of the lipids levels, C-reactive protein and adiponectin in adolescent male by fat intake

The purpose of this study was to investigate the relationship between dietary fat intake, anthropometric data, blood lipids, C-reactive protein, and adiponectin in Korean male college students. Forty-eight subjects were divided into 2 groups based on dietary fat intake: UERF (under 30% of energy ratio for fat source), AERF (above 30% of energy ratio for fat souce). We collected dietary intake data using 24-hour dietary recall for 3 days. Anthropometric and biochemical parameters were measured by using standard methods. Segmental body composition analysis was carried out using an 8-electrode multifrequency bioelectrical impedance method of body fat estimation. There was no significant difference in anthropometric data and serum lipid profile between UERF and AERF group. Serum C-reactive protein level was significantly higher in the AERF group compared to the UERF group. Although there was no significant difference in serum adiponectin level between UERF and AERF groups, subjects had lower adiponectin levels. Correlation data show that serum adiponectin level was positively correlated with vegetable intake (p < 0.05). In addition, dietary fat intake had a positive correlation with meat (p < 0.01), whereas a negative correlation with grain (p < 0.01), vegetables (p < 0.05), and fish (p < 0.05). These results suggest that the increased fat intake of non-obese Korean male college students is associated with their increased serum C-reactive protein concentration. Therefore, proper guidelines on fat intake and nutrition education are necessary for the prevention and management of metabolic syndromes.