Publicação: Autonomic control of heart rate exhibits diurnal shifts in a crocodilian
Carregando...
Data
Orientador
Coorientador
Pós-graduação
Curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Editor
Tipo
Artigo
Direito de acesso
Resumo
Over the diurnal cycle most reptiles show large changes in internal body temperature and heart rate (fH). The raising of fH, as the surface of a heliothermic reptile warms, increases cardiac output and facilitates in optimising the preferred daily body temperature (PDBT). In mammals, the fine tuning of cardiac output by the autonomic system can be observed through distinct oscillatory patterns in fH. This study examined Caiman latirostris (n = 6) to determine if similar oscillations in fH were present, and to assess if they exhibited a diurnal component associated with daily shifts in body temperature. A surgically implanted miniature datalogger recorded every heart beat and the dorsal surface temperature (Tds) of animals free-ranging in a semi-natural habitat. All C. latirostris exhibited rapid warming of T ds between 0700 and 1200. This was correlated with a rapid increase in fH, accompanied by erratic beat-to-beat oscillations in instantaneous fH. As Tds cooled, fH decreased and the short-term oscillations were abolished, resulting in a much slower rate of change in instantaneous fH. The two distinct fH rhythms may serve to optimise the PDBT over the diurnal cycle. © 2008 Koninklijke Brill NV, Leiden.
Descrição
Palavras-chave
Heart rate variability, Hysteresis, Power spectral analysis, Thermoregulation
Idioma
Inglês
Como citar
Amphibia Reptilia, v. 29, n. 4, p. 567-571, 2008.
