| Seasonal, sexual, and individual variation in endurance and activity metabolism in lizards. | |
| | |
MedLine Citation:
|
PMID: 3826408 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Amphibolurus nuchalis were collected in central Australia during mid- (January) and late summer (March). Endurance time at 1 km/h on a motorized treadmill is greater in larger lizards, scaling as M0.65. Maximal O2 consumption (VO2max) scales as M0.96; standard metabolic rate (SMR) scales as M0.83. Factorial aerobic scope thus increases ontogenetically (9.4 at 1 g vs. 15 at 50 g). All organ masses scale allometrically; larger lizards have relatively smaller livers, but larger hearts and thigh muscles. Hematocrit and hemoglobin increase during early ontogeny, but are mass independent in adults. Maximal in vitro catalytic rates were determined for citrate synthase (CS) and pyruvate kinase (PK) in liver, heart, and thigh muscle and for lactate dehydrogenase (LDH) (lactate oxidation) in heart. All enzyme activities (expressed per g tissue) scale positively, except CS in heart. Females exhibit lower SMR and heart CS activity. March animals exhibit elevated endurance, VO2max, heart LDH, and thigh CS and PK activities. Individual variation in endurance correlates with individual differences in heart LDH and thigh CS and/or PK activities. Individual differences in VO2max are partly related to variation in hematocrit. |
| | |
Authors:
|
T Garland; P L Else |
Related Documents
:
|
700278 - Influence of phenformin and metformin on exercise induced lactataemia in patients with ... 17194228 - Variations in heart rate at blood lactate threshold due to exercise mode in elite cross... 12439078 - Method of lactate elevation does not affect the determination of the lactate minimum. 8056678 - Influence of treadmill exercise on pituitary-adrenal secretions, other blood constituen... 9252488 - An abundant supply of amino acids enhances the metabolic effect of exercise on muscle p... 833958 - The treatment of the uninhibited bladder with dicyclomine. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: The American journal of physiology Volume: 252 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1987 Mar |
Date Detail:
|
Created Date: 1987-04-16 Completed Date: 1987-04-16 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: R439-49 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Energy Metabolism* Female Hematocrit Hemoglobins / analysis Lizards / growth & development, physiology* Male Motor Activity Oxygen Consumption Physical Endurance* Seasons* Sex Characteristics* |
| Chemical | |
Reg. No./Substance:
|
0/Hemoglobins |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Atrioventricular interactions: a theoretical simulation study.
Next Document: Effects of endurance training and captivity on activity metabolism of lizards.