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[Purpose] This study aimed to examine the independent effect of electrical pulse stimulation( EPS) and nitric oxide(NO) on muscle contraction and their synergistic or combined effect on contraction phenomenon using C2C12 mouse skeletal muscle cells. [Methods] Some differentiated C2C12 myotube cells were untreated (control). Other cells did not receive EPS and did receive 0.5, 1.0, or 2.0 mM of the NO donor, S-nitroso-N-acetylpenicillamine (SNAP; -E/S0.5, -E/S1.0, and -E/S2.0, respectively). For the EPS treatments (0.3 V/mm, 1.0 Hz, and 4.0 ms), differentiated C2C12 myotube cells received only EPS or both EPS and the SNAPtreatments at the same concentrations (+E/-S, +E/S0.5, +E/ S1.0, and +E/S2.0, respectively). All samples were then cultured for 4 days. [Results] Differentiated C2C12 cellswere stimulated by the EPS, NO, and EPS+NO treatments. The cell length of the +E/S2.0 Group after the 4-day culture (84.2±13.2㎛) was the shortest of all the groups. The expressions of AMPK, JNK, Akt, eNOS, GLUT4, and PGC1α proteins were noticeably dominant. The results indicated synergistic effect on muscle contraction of simultaneously applied EPS and SNAP. [Conclusion] Motor skills were significantly improved when exercise was accompanied by the intake of NO precursor and/or NO, compared to that upon their independent application or treatment.

Edible insects are an interesting alternative global food resource. The purpose of this study was to investigate whether ingestion of silkworm (Bombyx mori) pupae powder with and without resistance exercise training (isometric contraction training) increased muscle mass in ICR mice. To achieve this, 28 ICR mice were grouped into control (CON), resistance exercise training (EX), silkworm pupae powder ingested control (SP), and silkworm powder ingestion with resistance exercise training (SPEX) groups. The change in body weight ratio was significantly decreased in the EX and SPEX groups compared to the CON and SP groups. Total blood protein levels were the highest in SPEX mice compared to those in other groups. The albumin concentration increased only in the EX group. Blood GOT and GPT levels were not significantly affected. Changes in Akt and Gsk- protein expression were not significant but there was a tendency for Akt to increase and for Gsk- to increase following the ingestion of the powder. The size of the gastrocnemius muscle increased significantly in response to resistance exercise training only. Furthermore, the ingestion of silkworm pupae powder tended to increase muscle mass without significance. These results suggested that the ingestion of silkworm pupae powder with resistance exercise training might enhance muscle mass without hepatotoxicity. However, future study may be needed to obtained detailed results and practical suggestions.

The purpose of this study was to analyze the effect of grasshopper (Oxya chinensis sinuosa) powder ingestion with/without aerobic exercise (treadmill running) on energy metabolism. To achieve this purpose, 28 Institute of Cancer Research (ICR) mice were divided into four groups: normal diet control group (CON), a normal diet with exercise control group (COEX), a grasshopper powder-supplemented diet group (GH), and a grasshopper powder-supplemented diet with exercise group (GHEX). Duration of the powder ingestion and aerobic exercise training were 6 weeks. Body weight gain ratio was not significant. Fat mass significantly decreased in GH and GHEX. There were no changes in blood glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels between groups. Glucose transporter type 2 and glucose transporter type 4 protein levels were not significantly different between groups. Fibronectin type III domain-containing protein 5 level was the highest in GHEX. AMP-activated protein kinase level significantly increased in GHEX compared to the levels in the other groups. Glycogen synthase kinase 3 beta protein level was reduced in GHEX compared to that in CON. These results suggest that grasshopper powder ingestion and endurance exercise training influence energy metabolism.