Linked Life Data

11246043

Source:http://linkedlifedata.com/resource/pubmed/id/11246043

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-3-14
pubmed:abstractText
Many ectothermic vertebrates ingest very large meals at infrequent intervals. The digestive processes associated with these meals, often coupled with an extensive hypertrophy of the gastrointestinal organs, are energetically expensive and metabolic rate, therefore, increases substantially after feeding (specific dynamic action, SDA). Here, we review the cardio-respiratory consequences of SDA in amphibians and reptiles. For some snakes, the increased oxygen uptake during SDA is of similar magnitude to that of muscular exercise, and the two physiological states, therefore, exert similar and profound demands on oxygen transport by the cardiorespiratory systems. In several species, SDA is attended by increases in heart rate and overall systemic blood flows, but changes in blood flow distribution remain to be investigated. In snakes, the regulation of heart rate appears to involve a non-adrenergic-non-cholinergic mechanism, which may be a regulatory peptide released from the gastrointestinal system during digestion. Digestion is also associated with a net acid secretion to the stomach that causes an increase in plasma HCO3- concentration (the 'alkaline tide'). Experiments on chronically cannulated amphibians and reptiles, show that this metabolic alkalosis is countered by an increased P(CO2), so that the change in arterial pH is reduced. This respiratory compensation of arterial pH is accomplished through a reduction in ventilation relative to metabolism, but the estimated reductions in lung P(O2) are relatively small. The SDA response is also associated with haematological changes, but large interspecific differences exist. The studies on cardiorespiratory responses to digestion may allow for a further understanding of the physiological and structural constraints that limits the ability of reptiles and amphibians to sustain high metabolic rates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1095-6433
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
535-49
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
The respiratory consequences of feeding in amphibians and reptiles.
pubmed:affiliation
School of Biosciences, The University of Birmingham, Edgbaston, UK. tobiaswang@hotmail.com
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't