Castellini M A, Murphy B J, Fedak M, Ronald K, Gofton N, Hochachka P W
J Appl Physiol (1985). 1985 Feb;58(2):392-9. doi: 10.1152/jappl.1985.58.2.392.
Metabolic replacement rates (Ra) for glucose and free fatty acids (FFA) were determined during rest, exercise, and diving conditions in the gray seal using bolus injections of radiotracers. In the exercise experiments the seal swam at a metabolic rate elevated twofold over resting Ra for glucose and FFA while resting were similar to values found in terrestrial mammals and other marine mammal species. During exercise periods glucose turnover increased slightly while FFA turnover changes were variable. However, the energetic demands of exercise could not be met by the increase in the replacement rates of glucose or FFA even if both were completely oxidized. Under diving conditions the tracer pool displayed radically different specific activity curves indicative of the changes in perfusion and metabolic rate associated with a strong dive response. Since the radiotracer curves during exercise and diving differed qualitatively and quantitatively, it is possible that similar studies on freely diving animals can be used to assess the role of the diving response during underwater swimming in nature.
利用放射性示踪剂的大剂量注射，测定了灰海豹在休息、运动和潜水状态下葡萄糖和游离脂肪酸（FFA）的代谢替换率（Ra）。在运动实验中，海豹游泳时的代谢率比休息时葡萄糖和FFA的Ra提高了两倍，而休息时的代谢率与陆生哺乳动物和其他海洋哺乳动物物种的值相似。在运动期间，葡萄糖周转率略有增加，而FFA周转率变化不定。然而，即使葡萄糖或FFA的替换率增加且二者都被完全氧化，运动的能量需求也无法得到满足。在潜水状态下，示踪剂池显示出截然不同的比活度曲线，表明与强烈潜水反应相关的灌注和代谢率变化。由于运动和潜水期间的放射性示踪剂曲线在质量和数量上都不同，因此对自由潜水动物进行类似研究有可能用于评估潜水反应在自然水下游泳中的作用。
