These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Roles of lactate and catecholamines in the energetics of brief locomotion in an ectothermic vertebrate.
    Author: Nedrow JM, Scholnick DA, Gleeson TT.
    Journal: J Comp Physiol B; 2001 Apr; 171(3):237-45. PubMed ID: 11352107.
    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 (VO2) increased from 0.16 ml O2 g(-1) 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 VO2 but depressed excess post-exercise oxygen consumption volumes 2540%. 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.
    [Abstract] [Full Text] [Related] [New Search]