Protein catabolism in suckling and fasting northern elephant seal pups ( Mirounga angustirostris )
| Autor: | Daniel Paul Costa, Dirceu Costa, Dorian Houser |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
medicine.medical_specialty
Tritiated water Nitrogen Seals Earless Physiology Biochemistry chemistry.chemical_compound Endocrinology Lactation Internal medicine medicine Elephant seal Animals Urea Ecology Evolution Behavior and Systematics biology Proteins Water Fasting biology.organism_classification Animals Suckling Mirounga angustirostris Protein catabolism Blood Milk medicine.anatomical_structure chemistry Body Composition Metabolic rate Lean body mass Female Animal Science and Zoology |
| Zdroj: | Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology. 171:635-642 |
| ISSN: | 1432-136X 0174-1578 |
| Popis: | Nursing elephant seal pups are hypothesized to be preadapted to the postweaning fast, yet no comparison of lipid or protein use for meeting metabolic costs has been made between these contrasting nutritional periods. To address this, protein catabolism was estimated in five elephant seal pups from measurements of urea turnover made twice during nursing and twice during the postweaning fast. Changes in body composition were measured in ten separate weaned pups via tritiated water dilution and matched to fasting urea turnover measurements in order to assess errors in protein catabolism derived from urea turnover rates. Estimates of lean mass loss based upon urea turnover and tritiated water dilution were in general agreement, supporting estimates of protein catabolism derived from urea turnover measurements. Protein catabolism was estimated to contribute less than 4% to the average metabolic rate of suckling and fasting pups implying strict protein conservation during both periods and supporting the shypothesis that suckling pups are pre-adapted to fasting. It is proposed that strict protein conservation across suckling and fasting compensates for relative reductions in maternal investment associated with the abbreviated lactation period of the elephant seal. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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