著者

Natsuki TSUJITA Yasunori AKAMATSU Márcio Makoto NISHIDA Tatsuya HAYASHI Toshio MORITANI

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.65, no.6, pp.507-514, 2019-12-31 (Released:2019-12-31)

参考文献数

51

被引用文献数

13

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Tryptophan (TRP), a precursor of serotonin is believed to have an antidepressant effect. The pathway for brain uptake of TRP is shared by other large neutral amino acids; therefore, the best time to take TRP may be between meals. No previous study has, however, designated the time of TRP dosing to improve mood. Further, the effects of TRP on autonomic nervous system (ANS) activity are unclear. This study investigated the effects of TRP, vitamin B6, and nicotinamide-containing supplements loading between meals on mood and ANS activity in depressive young adults. Thirty depressive young adults were randomly allocated to receive TRP, vitamin B6, and nicotinamide-containing supplements or a placebo supplements twice daily between meals for 7 d. Mood was measured using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Profile of Mood States (POMS). ANS activities were analyzed by heart rate variability power spectral analysis. Blood samples were assayed for plasma total TRP concentration. For analysis, TRP and placebo groups were further classified into two subgroups according to CES-D score (mild to moderate vs. severe depressive symptoms). The CES-D score significantly improved following both treatments in the severe depression subgroups, while the POMS depression score was significantly improved only in the TRP severe depression subgroup. There was no significant change in ANS activity or plasma total TRP in any group. TRP, vitamin B6, and nicotinamide-containing supplements loading between meals can quickly improve depressed mood in quite low dose in young adults with severe subclinical depression.

著者

Ayumi Goto Keiichi Sekine Rieko Oshima Ichika Sakon Mayu Iwamoto Tomohiko Osaki Kotaro Haga Tatsuya Hayashi Tatsuro Egawa

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.7, no.1, pp.87-93, 2018-01-25 (Released:2018-01-19)

参考文献数

37

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Heat stress (HS) is a potent stimulus for activating glucose metabolism in skeletal muscles. However, the effect of short-term HS on protein turnover in skeletal muscles is unclear. This study aimed to investigate the effect of short-term HS on protein synthesis and protein degradation in skeletal muscles. The epitrochlearis muscle was isolated from male Sprague–Dawley rats weighing 150-160 grams (g) and incubated with or without HS at 42°C for 10 or 30 min in alpha minimum essential medium. HS for 30 min significantly decreased phosphorylation of 70-kDa ribosomal protein S6 kinase at Thr389 and 4E-binding protein 1 at Thr37/46. Correspondingly, HS for 30 min decreased the rate of protein synthesis. In contrast, HS had no effect on the expression of autophagy-related proteins, including microtubule-associated protein light chain 3 and p62, or on the mRNA expression of muscle-specific ubiquitin ligases, including muscle RING-finger 1 (MuRF1) and atrogin-1/MAFbx. These findings suggested that short-term HS for approximately 30 min is a physiologically relevant stimulus that suppresses protein synthesis signaling in skeletal muscles.