Linked Life Data

16344008

Source:http://linkedlifedata.com/resource/pubmed/id/16344008

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2006-4-17
pubmed:abstractText
The relative contribution of genetic and environmental influences to individual exercise capacity is difficult to determine. Accordingly, animal models in which these influences are carefully controlled are highly useful to understand the determinants of intrinsic exercise capacity. Studies of systemic O(2) transport during maximal treadmill exercise in two diverging lines of rats artificially selected for endurance capacity showed that, at generation 7, whole body maximal O(2) uptake ((.)V(O(2)(max)) was 12% higher in high capacity (HCR) than in low capacity runners (LCR) during normoxic exercise. The difference in (.)V(O(2)(max) between HCR and LCR was larger during hypoxic exercise. Analysis of the linked O(2) conductances of the O(2) transport system showed that the higher (.)V(O(2)(max) was not due to a higher ventilatory response, a more effective pulmonary gas exchange, or an increased rate of O(2) delivery to the tissue by blood. The main reason for the higher (.)V(O(2)(max) of HCR was an increased tissue O(2) extraction, due largely to a higher tissue diffusive O(2) conductance. The enhanced tissue O(2) diffusing capacity was paralleled by an increased capillary density of a representative locomotory skeletal muscle, the gastrocnemius, in HCR. Activities of skeletal muscle oxidative enzymes citrate synthase and beta-HAD were also higher in HCR than LCR. Thus, the functional characteristics observed during exercise are consistent with the structural and biochemical changes observed in skeletal muscle that imply an enhanced capacity for muscle O(2) uptake and utilization in HCR. The results indicate that the improved (.)V(O(2)(max) is solely due to enhanced muscle O(2) extraction and utilization. However, the question arises as to whether it is possible to maintain a continually expanding capacity for O(2) extraction at the tissue level with successive generations, without a parallel improvement in the capacity to deliver O(2) to the exercising muscles.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1569-9048
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
151
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
141-50
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Systemic oxygen transport in rats artificially selected for running endurance.
pubmed:affiliation
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160-7401, USA. ngonzale@kumc.edu <ngonzale@kumc.edu>
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural