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.

Ultrasonographic Evaluation of Needle Insertion Site for the Flexor Pollicis Longus

OBJECTIVE: To establish the safest approach to needle electrode insertion into the flexor pollicis longus (FPL) regarding possible needle injury to the superficial radial nerve (SRN) or radial artery by ultrasonography. METHODS: We evaluated 54 forearms of 27 healthy subjects. Three levels were defined in the forearm. Level 1 is the junction of the middle and distal third of the forearm, level 3 is the midpoint of forearm length, and level 2 is the midpoint between two levels. At each level, the distance between the most prominent point of the radius and the SRN (region A), the distance between the SRN and the radial artery (region B), and the depth from the skin surface to the FPL were measured. RESULTS: The distance of region A was 1.20+/-0.41 cm in level 1, 1.62+/-0.45 cm in level 2, and 1.95+/-0.49 cm in level 3. The distance of region B was 1.02+/-0.29 cm in level 1, 0.61+/-0.24 cm in level 2, and 0.37+/-0.19 cm in level 3. The depth from the skin surface to the FPL was 0.92+/-0.20 cm in level 1, 1.14+/-0.26 cm in level 2, and 1.45+/-0.29 cm in level 3. CONCLUSION: The safest needle insertion point to the FPL is the middle of the forearm within approximately 0.8 cm from the most prominent point of the radius. We recommend that the needle is inserted at the above point perpendicular to the skin surface until the needle meets the FPL at a depth of approximately 1.45 cm from the skin surface.