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- 箭原 修
- 旭川医科大学第1内科
書誌事項
- タイトル別名
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- Adaptation of the respiratory muscles to long endurance training - Experimental studies with the rat.
- Experimental Studies with the Rat
抄録
Long endurance training for 10 weeks was performed with female Wistar rats employing a treadmill. A difference in the mean body weight was found between the control and the training group. The histochemical profile, the capillary supply and the energy metabolism of the respiratory muscles (the diaphragm, the external intercoastal muscle and the internal intercostal muscle) were analysed. The respiratory muscles could be classified into four types by myosin ATPase staining. These are type 1 fiber (slow twitch oxidative or slow fatigue resistant fiber), type 2A fiber (fast twitch exidative glycolytic or fast fatigue resistant fiber), type 2B fiber (fast twitch glycolytic or fatigable fiber) and type 2C fiber (primitive fiber).<br>Although the percentage of the number and the relative area of type 1 fiber and type 2C fiber increased after training, those of type 2A fiber were apparently decreased in the diaphragm, in contrast with the intercostal muscles. It was speculated that type 2A fiber were transformed to type 1 fiber via type 2C fiber as the result of endurance training.<br>Capillary density and the capillary-to-fiber ratio (C/F ratio) of the diaphragm were higher than that of the intercostal muscles. After the training, C/F ratio was increased in the diaphragm, but not in the intercostal muscles.<br>Lipoprotein lipase (LPL) activity in the diaphragm was higher than in the intercostal muscles even in the control. Moreover, training caused further elavation in the LPL activity in the diaphragm, but no change in the intercostal muscles.<br>The diaphragm responded to long endurance training with significant increase in the oxidative capacity, capillary-to-fiber ratio and LPL activity and adapted to become resistant to fatigue. These findings also support the proposal that the availability of metabolic energy differs between the diaphragm and the intercostal muscles.
収録刊行物
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- 日本胸部疾患学会雑誌
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日本胸部疾患学会雑誌 25 (8), 835-842, 1987
社団法人 日本呼吸器学会