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Titolo:
The respiratory consequences of feeding in amphibians and reptiles
Autore:
Wang, T; Busk, H; Overgaard, J;
Indirizzi:
Aarhus Univ, Lab Zoophysiol, Inst Biol, Dept Zoophysiol, DK-8000 Aarhus C,Denmark Aarhus Univ Aarhus Denmark C , Dept Zoophysiol, DK-8000 Aarhus C,Denmark Univ Birmingham, Sch Biosci, Edgbaston, England Univ Birmingham Edgbaston England ngham, Sch Biosci, Edgbaston, England Univ So Denmark, Inst Biol, Odense, Denmark Univ So Denmark Odense Denmark v So Denmark, Inst Biol, Odense, Denmark
Titolo Testata:
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
fascicolo: 3, volume: 128, anno: 2001,
pagine: 535 - 549
SICI:
1095-6433(200103)128:3<535:TRCOFI>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
GASTROINTESTINAL BLOOD-FLOW; ALLIGATOR ALLIGATOR-MISSISSIPPIENSIS; POSTPRANDIAL ALKALINE TIDE; GASTRIC-ACID SECRETION; TOAD BUFO-MARINUS; COD GADUS-MORHUA; DYNAMIC ACTION; GAS-EXCHANGE; ESTUARINE CROCODILE; CROCODYLUS-POROSUS;
Keywords:
reptile; amphibian; feeding; SDA; digestion; blood gases; cardiovascular; ventilatory responses; acid-base balance; blood oxygen transport;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
101
Recensione:
Indirizzi per estratti:
Indirizzo: Wang, T Aarhus Univ, Lab Zoophysiol, Inst Biol, Dept Zoophysiol, Bldg 131,Univ Pk,DK-8000 Aarhus C, Denmark Aarhus Univ Bldg 131,Univ Pk Aarhus Denmark C 0 Aarhus C, Denmark
Citazione:
T. Wang et al., "The respiratory consequences of feeding in amphibians and reptiles", COMP BIOC A, 128(3), 2001, pp. 535-549

Abstract

Many ectothermic vertebrates ingest very large meals at infrequent intervals. The digestive processes associated with these meals, often coupled withan extensive hypertrophy of the gastrointestinal organs, are energeticallyexpensive and metabolic rate, therefore, increases substantially after feeding (specific dynamic action, SDA). Here, we review the cardio-respiratoryconsequences 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 slates, 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 HCO; concentration (the 'alkaline tide'). Experiments on chronicallycannulated 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 furtherunderstanding of the physiological and structural constraints that limits the ability of reptiles and amphibians to sustain high metabolic rates. (C)2001 Elsevier Science Inc. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/04/20 alle ore 22:18:50