ADAPTATIONS IN PECTORALIS-MUSCLE, HEART MASS, AND ENERGY-METABOLISM DURING PREMIGRATORY FATTENING IN SEMIPALMATED SANDPIPERS (CALIDRIS-PUSILLA)
ADAPTATIONS IN PECTORALIS-MUSCLE, HEART MASS, AND ENERGY-METABOLISM DURING PREMIGRATORY FATTENING IN SEMIPALMATED SANDPIPERS (CALIDRIS-PUSILLA)
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DOI：
10.1139/z93-226
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发表时间：
1993-08-01
影响因子：
1.4
通讯作者：
SEPHTON, DH
中科院分区：
文献类型：
--
作者：
DRIEDZIC, WR;CROWE, HL;SEPHTON, DH
在夏末，半蹼矶鹬（Calidris pusilla）从不间断地从加拿大东部迁徙到南美洲西北海岸的越冬地点。在越洋飞行之前，这些鸟密集进食大约15天，在此期间脂肪被储存起来。在增肥期间，胸肌的无脂干质量增加，可能增加了肌肉的最大功率输出。血浆游离脂肪酸和甘油三酯、胸肌脂质含量和肉碱油酰辅酶A转移酶活性在重（肥）禽中高于轻（瘦）禽。这些变化意味着在迁移过程中利用脂肪酸作为代谢燃料的能力增强。总胸肌糖原水平和丙酮酸激酶活性增加，表明糖原溶解能力增强，这在能量需求强烈时可能很重要。心脏大小和每克组织的蛋白质含量随着体重的增加而增加。然而，关键的线粒体酶，柠檬酸合酶和肉碱油酰辅酶A转移酶的总水平没有变化，这表明在心脏中总蛋白含量的增加没有发生线粒体蛋白的增加。
In late summer, semipalmated sandpipers (Calidris pusilla) migrate nonstop from eastern Canada to wintering sites on the northwest coast of South America. Before their transoceanic flight, the birds feed intensively for about 15 days during which time lipids are stored. The fat-free dry mass of the pectoralis muscle increases during the fattening period, probably increasing the maximal power output of the muscle. Plasma free fatty acids and triglycerides, pectoralis muscle lipid content, and the activity of carnitine oleoyl coenzyme A transferase are higher in heavy (fat) than in light (lean) birds. These alterations imply an enhanced capacity to utilize fatty acids as a metabolic fuel during migration. Total pectoralis muscle glycogen levels and the activity of pyruvate kinase increase, suggesting a higher capacity for glycogenolysis, which may be important during intense levels of energy demand. Heart size and protein content per gram of tissue increase in association with an increase in body mass. However, total levels of key mitochondrial enzymes, citrate synthase and carnitine oleoyl coenzyme A transferase, do not change, suggesting that in the heart an increase in total protein content occurs without an increase in mitochandrial proteins.