Biochemical Correlates of Swimming and Diving Behavior in the Little Penguin Eudyptula minor
Biochemical Correlates of Swimming and Diving Behavior in the Little Penguin Eudyptula minor
复制标题
小企鹅 Eudyptula 小企鹅游泳和潜水行为的生化相关性
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
J. Baldwin
中科院分区：
文献类型：
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作者：
G. Mill;J. Baldwin
通过检测氧气储备、肌肉超微结构、分解代谢酶的活性和性质以及肌肉缓冲能力，研究了小企鹅游泳时肌肉利用有氧和无氧代谢的程度。血液中的血红蛋白和肌肉中的肌红蛋白含量高。肌肉细胞含有大量的脂滴，极少的糖原和大量的大线粒体。短爆发型飞行员的最大限速糖酵解酶活性相对于胸肌肌来说并不高。与帝王企鹅和阿德利企鹅的肌肉相比，胸肌和胸骨上肌的LDH M亚基比例较低，对LDH活性的丙酮酸抑制作用更大。最大克雷布斯循环通量可能低于能够快速持续飞行的鸟类。游泳肌的缓冲能力低于帝王企鹅和阿德利企鹅或潜水哺乳动物。这些结果表明，小企鹅游泳时所用的肌肉基本上是有氧的，在肌肉缺氧时产生ATP的能力有限。这表明，这些鸟类不会过度依赖短时间的快速游泳，也不会沉迷于长时间的深潜，以至于游泳肌肉可用的氧气储备耗尽。
The extent to which the muscles powering swimming in the little penguin utilize aerobic and anaerobic metabolism was investigated by examining oxygen stores, muscle ultrastructure, the activities and properties of catabolic enzymes, and muscle buffering capacity. Blood hemoglobin and muscle myoglobin contents are high. Muscle cells contain many lipid droplets, little glycogen, and numerous large mitochondria. Maximum activities of rate-limiting glycolytic enzymes are not high relative to pectoralis muscle of short-burst type flyers. The pectoralis and supracoracoideus have a lower proportion of LDH M subunits and display greater pyruvate inhibition of LDH activity than these muscles of emperor and Adléie penguins. The maximum Krebs cycle flux may be lower than in birds capable of rapid sustained flight. The buffering capacities of the swimming muscles are lower than in emperor and Adélie penguins or in diving mammals. These results show that the muscles used to power swimming in the little penguin are basically aerobic with limited capacity for producing ATP during muscle anoxia. This suggests that these birds do not rely extensively upon short bursts of rapid swimming or indulge in prolonged deep diving to a point where oxygen stores available to the swimming muscles are exhausted.