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Journal of Comparative Physiology B

, Volume 171, Issue 3, pp 237–245 | Cite as

Roles of lactate and catecholamines in the energetics of brief locomotion in an ectothermic vertebrate

  • Jeffrey M. Nedrow
  • David A. Scholnick
  • Todd T. Gleeson
Original Paper

Abstract.

We have investigated the magnitude and duration of excess post-exercise oxygen consumption (EPOC) in a lizard following a single bout of vigorous exercise of 5–60 s, common activity durations for many ectothermic vertebrates. Desert iguanas (Dipsosaurus dorsalis) were run for 5 s, 15 s, 30 s, or 60 s. Oxygen consumption (\(\dot VO_2\) ) increased from 0.16 ml O2 g1 h–1 at rest to 1.3–1.6 ml O2 g–1 h–1 during 5–60 s of running. EPOC duration increased with activity duration, ranging from 35–63 min. EPOC volume, the excess oxygen consumed post-exercise, doubled from 0.13 ml O2 g–1 following 5 s of activity to 0.25 ml O2 g–1 after 60 s. EPOC represented 91–98% of the total metabolic expense of the activity. EPOC durations were always shorter than the period required for lactate removal, illustrating that these two processes are not causally related. Alpha- and beta-adrenergic receptor blockade by phentolamine and propranolol had no effect on resting \(\dot VO_2\) but depressed excess post-exercise oxygen consumption volumes 25–40%. The extent of catechol stimulation post-exercise may be motivation or stimulus dependent. The data indicate that metabolic elevations post-exercise represent the majority of activity costs in lizards. The study suggests that EPOC of ectothermic vertebrates is sensitive to exercise duration and catecholamine release post-activity, even when activity periods are less than 60 s in duration.

Exercise Lactate Oxygen consumption Lizard, Dipsosaurus dorsalis Oxygen debt 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • Jeffrey M. Nedrow
    • 1
  • David A. Scholnick
    • 1
  • Todd T. Gleeson
    • 1
  1. 1.Department of Environmental, Population, and Organismic Biology, University of Colorado, Boulder, CO 80309-0334, USA

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