Publications by authors named "Atsuko Koike"

Article Synopsis
  • Acute endurance exercise impacts pancreatic amylase activity, with a notable decrease observed only after high-intensity (20 m/min) exercise, while low-intensity (10 m/min) exercise had no significant effect.
  • High-intensity exercise also affects muscle glycogen recovery, as mice fed a starch solution after exercise had lower glycogen accumulation compared to those given glucose.
  • Overall, the study indicates that the intensity of exercise alters carbohydrate digestion and recovery, highlighting that high-intensity activity can impair the pancreas's ability to process carbohydrates efficiently.
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Extensive research has confirmed numerous advantages of exercise for promoting brain health. More recent studies have proposed the potential benefits of lactate, the by-product of exercise, in various aspects of brain function and disorders. However, there remains a gap in understanding the effects of lactate dosage and its impact on aged rodents.

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Introduction: Iron is an essential micronutrient that plays a crucial role in various biological processes. Previous studies have shown that iron supplementation is related to exercise performance and endurance capacity improvements. However, the underlying mechanisms responsible for these effects are not well understood.

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The role of Peroxisome proliferator-activated receptor-gamma coactivator alpha (PGC-1α) in fat metabolism is not well known. In this study, we compared the mechanisms of muscle-specific PGC-1α overexpression and exercise-related adaptation-dependent fat metabolism. PGC-1α trained (PGC-1α Ex) and wild-trained (wt-ex) mice were trained for 10 weeks, five times a week at 30 min per day with 60 percent of their maximal running capacity.

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Objectives: This study was performed to assess the effects of long-term intake of a very high carbohydrate (VHCHO) diet (76% of total energy from carbohydrate [CHO]) on whole-body glucose tolerance and hepatic insulin resistance.

Methods And Materials: Male Sprague Dawley rats were fed either a control high-CHO diet (59% total energy from CHO; n = 8) or a VHCHO diet (76% total energy from CHO; n = 8) for 17 wk. At 4, 8, 12, and 16 wk of the dietary intervention, oral glucose tolerance test and homeostasis model assessment of insulin resistance (HOMA-IR) measurements were taken to assess whole-body glucose tolerance and hepatic insulin resistance, respectively.

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We previously reported that the combination of a very high-carbohydrate diet and endurance training increased glucose transporter 4 and glycogen concentration in skeletal muscle. However, it remains unclear whether they also affect the digestive and absorptive capacity in the pancreas and small intestine, which are suggested to be rate-limiting steps in the delivery of exogenous carbohydrates to skeletal muscle and muscle glycogen synthesis. Thus, we aimed to evaluate the effects of a very high-carbohydrate diet and endurance training on pancreatic amylase activity and intestinal glucose transporters in rats and to examine the relationship between these adaptations and their influence on muscle glycogen concentration.

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Endurance exercise training enhances muscle fat oxidation while concomitantly reducing carbohydrate (glycogen) utilization during exercise, thereby delaying the onset of fatigue. This study examined the effects of dietary fat restriction on endurance training-induced metabolic adaptations in rat skeletal muscle. Male Sprague-Dawley rats were placed on either a control diet (CON: 19.

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Long-term intake of a ketogenic diet enhances utilization of ketone bodies, a particularly energy-efficient substrate, during exercise. However, physiological adaptation to an extremely low-carbohydrate diet has been shown to upregulate pyruvate dehydrogenase kinase 4 (PDK4, a negative regulator of glycolytic flux) content in skeletal muscle, resulting in impaired high-intensity exercise capacity. This study aimed to examine the effects of a long-term ketogenic diet containing medium-chain triglycerides (MCTs) on endurance training-induced adaptations in ketolytic and glycolytic enzymes of rat skeletal muscle.

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