Daily rhythms of nonshivering thermogenesis in common spiny mice Acomys cahirinus under short and long photoperiods |
| |
Authors: | A Haim and N Zisapel |
| |
Institution: | a Department of Biology, University of Haifa at Oranim, Kiryat Tivon, 36006, Israel b Department of Neurobiochemistry, Tel Aviv University, Tel Aviv, 69978, Israel |
| |
Abstract: | Daily rhythms of nonshivering thermogenesis NST were studied in common spiny mice Acomys cahirinus, acclimated to different photoperiod regimes (16L:8D and 8L:16D) at a constant ambient temperature of 26°C. Noradrenaline NA (1.5 mg/kg subcutaneous) was injected at: 06:00, 12:00, 18:00 and 24:00 h (±15 min). NST was measured as the ratio between the maximal oxygen consumption (VO2) as response to NA — VO2NA and VO2 measured at 26°C — VO2 min. Rectal temperatures TbNA and Tb min respectively were recorded at the end of VO2 measurements. Significant variations in Tb min, TbNA, and NST were revealed, under the two different photoperiod regimes. Significant differences in VO2 min, NST, Tb min and TbNA were also recorded within each photoperiod acclimation group. These results suggest that daily and photoperiod depended variations in the brown adipose tissue activity, presumably emerge from amount of unoccupied receptors or changes in the receptors affinity to NA. |
| |
Keywords: | Nonshivering thermogenesis Noradrenaline Daily rhythms Body temperature Oxygen consumption Photoperiod manipulations Rodents Spiny mice Arid environment Metabolic rates Brown adipose tissue Nocturnal activity |
本文献已被 ScienceDirect 等数据库收录! |
|