- 著者
- Naohisa NOSAKA Yoshie SUZUKI Akira NAGATOISHI Michio KASAI Jian WU Motoko TAGUCHI
- 出版者
- Center for Academic Publications Japan
- 雑誌
- Journal of Nutritional Science and Vitaminology (ISSN:03014800)
- 巻号頁・発行日
- vol.55, no.2, pp.120-125, 2009 (Released:2009-05-12)
- 参考文献数
- 31
- 被引用文献数
- 2 20 20
Medium-chain triacylglycerols (MCT) are known to hydrolyze readily and completely to fatty acids and to be metabolized more easily by β-oxidation than long-chain triacylglycerols (LCT). Therefore, we investigated the effect of 2 wk of ingestion of food containing a small amount (6 g) of MCT on energy metabolism during moderate-intensity exercise and high-intensity exercise in recreational athletes. For comparison, the subjects were administered food containing MCT or LCT for 14 d, and were instructed to perform cycle ergometer exercise at a workload corresponding to 60% peak O2 uptake (VO2) for 40 min followed by a workload corresponding to 80% peak VO2 until exhaustion. Blood lactate concentration, VO2, VCO2, and rating of perceived exertion (RPE) were measured at rest and during exercise. The exercise time to exhaustion at a workload corresponding to 80% peak VO2 was significantly (p<0.05) longer in the MCT trial (10.2±7.6 min; mean±SD) than in the LCT trial (5.8±3.3 min). Blood lactate concentration and RPE during exercise were significantly (p<0.05) lower after ingestion of MCT-containing food. Fat oxidation rate was higher and carbohydrate oxidation rate was lower during exercise in the MCT trial than in the LCT trial, but the differences were not significant. These results indicate that the ingestion of MCT-containing food may suppress utilization of carbohydrate for energy production because of increased utilization of fatty acids for generating energy. In conclusion, our data suggest that short-term ingestion of food containing a small amount of MCT suppresses the increase in blood lactate concentration and RPE during moderate-intensity exercise and extends the duration of subsequent high-intensity exercise, at levels higher than those achieved by ingestion of LCT-containing food.
- 著者
- Lei Zhang Baoli Zhang Ying Yu Jingfeng Wang Jian Wu Yangang Su Hong Jiang Yunzeng Zou Junbo Ge
- 出版者
- International Heart Journal Association
- 雑誌
- International Heart Journal (ISSN:13492365)
- 巻号頁・発行日
- vol.62, no.1, pp.162-170, 2021-01-30 (Released:2021-01-30)
- 参考文献数
- 44
- 被引用文献数
- 5
High-mobility group box 1 (HMGB1) is increased in the myocardium under pressure overload (PO) and is involved in PO-induced cardiac remodeling. The mechanisms of the upregulation of cardiac HMGB1 expression have not been fully elucidated. In the present study, a mouse transverse aortic constriction (TAC) model was used, and an angiotensin II (Ang II) type 1 (AT1) receptor inhibitor (losartan) or Ang II type 2 (AT2) receptor inhibitor (PD123319) was administrated to mice for 14 days. Cardiac myocytes were cultured and treated with Ang II for 5 minutes to 48 hours conditionally with the blockage of the AT1 or AT2 receptor. TAC-induced cardiac hypertrophy was observed at 14 days after the operation, which was partially reversed by losartan, but not by PD123319. Similarly, the upregulated HMGB1 expression levels observed in both the serum and myocardium induced by TAC were reduced by losartan. Elevated cardiac HMGB1 protein levels, but not mRNA or serum levels, were significantly decreased by PD123319. Furthermore, HMGB1 expression levels in culture media and cardiac myocytes were increased following Ang II treatment in vitro, positively associated with the duration of treatment. Similarly, Ang II-induced upregulation of HMGB1 in vitro was inhibited by both losartan and PD123319. These results suggest that upregulation of HMGB1 in serum and myocardium under PO, which are partially derived from cardiac myocytes, may be induced by Ang II via the AT1 and AT2 receptors. Additionally, amelioration of PO-induced cardiac hypertrophy following losartan treatment may be associated with the reduction of HMGB1 expression through the AT1 receptor.