title: Thermoregulatory and metabolic responses to hypoxia in the oviparous lizard, Phrynocephalus przewalskii.
abstract: The effects of hypoxia on behavioral thermoregulation, rate of heating and cooling, hysteresis of heart rate, and standard metabolic rate (SMR) were investigated in Phrynocephalus przewalskii, a small size toad headed lizard. Preferred temperature (T(b)) descended when lizards were exposed to severe hypoxia (8% O(2) and 6% O(2)) for 22 h, and lizards were able to maintain preferred T(b) after one week at 12% and 8% O(2) respectively. The period of heating increased after being treated with hypoxia (12% and 8% O(2)) for one week. Hysteresis of heart rate appeared at any given body temperature and oxygen level except at 39 °C and 40 °C at 8% O(2). SMR significantly increased after one-week acclimatization to 12% and 8% O(2) when ambient temperature (T(a)) was 25 °C, however, it did not change at 35 °C. Thus, we suggest that P. przewalskii has special thermoregulatory and metabolic mechanisms to acclimatize to the hypoxic environment.
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, 222 Tianshui South Road, Lanzhou, 730000, PR China.
authors.forename: Jianzheng
authors.initials: J
authors.lastname: He
authors.forename: Minghui
authors.initials: M
authors.lastname: Xiu
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Tang
authors.forename: Ningbo
authors.initials: N
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xin
authors.forename: Weixin
authors.initials: W
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D000860:Hypoxia / Q000503:physiopathology*; D008116:Lizards / Q000502:physiology*; D008297:Male; D015999:Multivariate Analysis; D052285:Ovoviviparity; D013696:Temperature; D013997:Time Factors