Metabolic and hormonal changes during the molt of captive gray seals (Halichoerus grypus).
Am J Physiol
; 270(5 Pt 2): R1051-8, 1996 May.
Article
em En
| MEDLINE
| ID: mdl-8928905
ABSTRACT
Body mass, resting metabolic rates (RMRs), and serum thyroid hormones concentrations of six captive gray seals (Halichoerus grypus) were measured at regular intervals before, during, and after the annual molt. Changes in body mass suggested that the animals had increased energy expenditures during the last stage of the molt. These were associated with significantly elevated RMRs during the molt, the increase being more pronounced in juveniles ( < or = 53%) than in adults ( < or = 17%). The increase in RMR probably reflects the cost of generating a new pelt or to sustain a high skin temperature. Serum total and free thyroxine concentrations were elevated for all animals during the molt, but only juveniles had elevated serum triiodothyronine concentration. The increase in thyroid hormones occurred only during the last stage of the molt, suggesting that the role of thyroid hormones during the molt may be to sustain rapid hair growth in the last stage of molt or to maintain elevated heat production, rather than to initiate hair growth.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Muda
/
Focas Verdadeiras
/
Hormônios
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1996
Tipo de documento:
Article