Low-Frequency Electroacupuncture Improves Insulin Sensitivity in Obese Diabetic Mice through Activation of SIRT1/PGC-1α in Skeletal Muscle

Electroacupuncture (EA) has been observed to reduce insulin resistance in obesity and diabetes. However, the biochemical mechanism underlying this effect remains unclear. This study investigated the effects of low-frequency EA on metabolic action in genetically obese and type 2 diabetic db/db mice. Nine-week-old db/m and db/db mice were randomly divided into four groups, namely, db/m, db/m + EA, db/db, and db/db + EA. db/m + EA and db/db + EA mice received 3-Hz electroacupuncture five times weekly for eight consecutive weeks. In db/db mice, EA tempered the increase in fasting blood glucose, food intake, and body mass and maintained insulin levels. In EA-treated db/db mice, improved insulin sensitivity was established through intraperitoneal insulin tolerance test. EA was likewise observed to decrease free fatty acid levels in db/db mice; it increased protein expression in skeletal muscle Sirtuin 1 (SIRT1) and induced gene expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and acyl-CoA oxidase (ACOX). These results indicated that EA offers a beneficial effect on insulin resistance in obese and diabetic db/db mice, at least partly, via stimulation of SIRT1/PGC-1α, thus resulting in improved insulin signal

低酸素耐性と心拍出量

低酸素に対する循環系の適応機能の中で,とくに右心活動が重要な因子であることを推定し,impednce法により適応時の左心および右心拍出量の相互関孫を中心にウサギを使用して解析した。呼吸数,心拍数,血圧などの循環機能は低酸素耐性とそれぞれ相関が認められ,とくに呼吸数,心拍数等は平地での値が,すでに耐性と相関を示すことが認められた。一回拍出量は高度上昇時および一定高度滞留中増加するが,心拍数は減少し毎分拍出量は減少した。低酸素耐性と右心毎分拍出量は高い相関があり,右心の活動水準の大きさが低酸素耐性の大きな因子となった。It has been assumed that the right heart activity holds an important key concerning tolerance and adaptability to altitude. To clarify this point, the relationship between the stroke volumes of the right and left heart at sea level and at altitude was analysed in rabbits. Respiratory rate, heart rate, blood pressure, and pulse pressure at altitude had considerable correlations with altitude-tolerance. Especially, the value of the first two functions even at sea level showed the correlation to altitude-tolerance with high significance. The stroke volume and heart rate tend to increase and decrease respectively throughout the process of ascending and staying at altitude, so that the cardiac output showed a tend to deccrease. Because of the high correlation between cardiac output of right heart and altitude-tolerance, the activity level of right heart is considered to be one of the most important factors for the adaptation to altitude