Homeothermy in neonatal chicks exposed to low environmental temperature with or without intracerebroventricular administration of corticotropin‐releasing factor

Abstract

To determine the mechanism of sensitivity to lowtemperature exposure (20°C for 3 h) and corticotropin-releasing factor (CRF) induced increased homeothermy, we investigated gene transcripts of putative thermogenic proteins and mitochondrial fatty acid (FA)-oxidation enzymes in neonatal chicks. The hypothalamic-pituitary-adrenal (HPA) axis in low-temperature-exposed neonatal chicks was activated by central administration of CRF. Neonatal chicks showed hypothermia on exposure to low-temperature, with no enhancement of HPA axis and gene transcripts of avian adenine nucleotide translocator, avian uncoupling protein, avian peroxisome-proliferator-activated receptor-c co-activator-1a, and mitochondrial FA transport and oxidation enzymes in vital organs. However, central administration of CRF activated the HPA axis under low environmental temperature and induced increased homeothermy that was associated with the enhancement of gene transcripts and activities of mitochondrial FA-oxidation enzymes in the liver and heart.

The role of temperature as a driver of metabolic flexibility in the Red-billed Leiothrix (Leiothrix lutea)

“…This finding is in agreement with previous studies in cold acclimated Dark-eyed Juncos (Junco hyemalis) (Swanson et al 2014), and seasonally acclimatized Chinese Bulbuls (Zheng et al 2010(Zheng et al , 2014a, Eurasian Tree Sparrows (Liu et al 2008;Zheng et al 2008bZheng et al , 2014b, and in rodents, including Plateau Pikas (Ochotona curzoniae) (Wang et al 2006a) and Root Voles (Microtus oeconomus) (Wang et al 2006b). However, other species show no significant temperature or seasonal variation in liver, muscular state-4 respiration, or COX activity (Mujahid and Furuse 2008;Teulier et al 2010), indicating that cold or winter-induced increases in cellular aerobic capacity are not uniform among small birds. Our results suggest that the leiothrix uses two, organ-specific, adaptive strategies to regulate its body temperature.…”

COMPARATIVE EVALUATION OF THE PECULIARITIES OF STRESS REACTIVITY OF THE RUSSIAN WHITE BREED CHICKEN WITH sw+ MUTATION AND AMROX IN HYPOTHERMIA CONDITIONS DURING EMBRYONAL AND EARLY POSTNATAL PERIODS OF ONTOGENESIS

“…У 1-суточных цыплят этого не происходит (26). В 1-суточном возрасте реакцией на пониженную температуру также становится усиление процессов липолиза, что сопровождается повышением содержания свободных жирных кислот в крови (27)(28)(29).…”