Skip to main content

Hibernating black bears have blood chemistry and plasma amino acid profiles that are indicative of long-term adaptive fasting

Buy Article:

$50.00 plus tax (Refund Policy)

Blood samples were drawn from six black bears (Ursus americanus Pallas, 1780) active in the summer and six others in early and late hibernation. Plasma urea:creatinine ratios and concentrations of amino acids, alanine aminotransferase, and aspartate aminotransferase dropped during the winter denning season, suggesting a decreased protein breakdown. Fifteen amino acids (3 branched chain and 12 glucogenic) were lower in the early winter than in the summer, but 6 of these amino acids rose back to summer levels by the late denning season. Hydroxyproline and glycine were also elevated during late winter, suggesting an increase in collagen breakdown. This profile suggests a dynamic process of adaptive fasting and protein conservation during the winter with a mobilization of non-myofibrilar collagen and perhaps smooth muscle protein reserves to augment a potential but slight increased breakdown of skeletal muscle during the late winter.

Nous avons effectué des prélèvements sanguins chez six ours noirs (Ursus americanus Pallas, 1780) actifs en été et chez six autres au début et à la fin de l'hibernation. Les rapports uréique : créatinine du plasma, ainsi que les concentrations d'acides aminés, d'alanine aminotransférase et d'aspartate aminotransférase, diminuent durant la période passée au terrier en hiver, ce qui indique une réduction du catabolisme des protéines. Quinze acides aminés (3 ramifiés et 12 glycogéniques) sont moins abondants au début de l'hiver qu'en été, mais 6 d'entre eux retournent aux concentrations d'été vers la fin de la période au terrier. Les concentrations d'hydroxyproline et de glycine sont aussi élevées à la fin de l'hiver, ce qui laisse croire à un catabolisme accéléré du collagène. Un tel profil indique un processus dynamique de jeûne adaptatif et de conservation des protéines durant l'hiver et une mobilisation du collagène non associé aux myofibrilles et peut-être aussi des réserves des protéines des muscles lisses, ce qui augmente un catabolisme potentiel accru, mais faible, du muscle squelettique à la fin de l'hiver.[Traduit par la Rédaction]
No References
No Citations
No Supplementary Data
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2005-09-01

More about this publication?
  • Published since 1929, this monthly journal reports on primary research contributed by respected international scientists in the broad field of zoology, including behaviour, biochemistry and physiology, developmental biology, ecology, genetics, morphology and ultrastructure, parasitology and pathology, and systematics and evolution. It also invites experts to submit review articles on topics of current interest.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more