Metabolic characteristics and response to high altitude in Phrynocephalus erythrurus (Lacertilia: Agamidae), a lizard dwell at altitudes higher than any other living lizards in the world.
Metabolic response to high altitude remains poorly explored in reptiles. In the present study, the metabolic characteristics of Phrynocephaluserythrurus (Lacertilia: Agamidae), which inhabits high altitudes (4500 m) and Phrynocephalusprzewalskii (Lacertilia: Agamidae), which inhabits low altitudes, were analysed to explore the metabolic regulatory strategies for lizards living at high-altitude environments. The results indicated that the mitochondrial respiratory rates of P. erythrurus were significantly lower than those of P. przewalskii, and that proton leak accounts for 74~79% of state 4 and 7~8% of state3 in P. erythrurus vs. 43~48% of state 4 and 24~26% of state3 in P. przewalskii. Lactate dehydrogenase (LDH) activity in P. erythrurus was lower than in P. przewalskii, indicating that at high altitude the former does not, relatively, have a greater reliance on anaerobic metabolism. A higher activity related to β-hydroxyacyl coenzyme A dehydrogenase (HOAD) and the HOAD/citrate synthase (CS) ratio suggested there was a possible higher utilization of fat in P. erythrurus. The lower expression of PGC-1α and PPAR-γ in P. erythrurus suggested their expression was not influenced by cold and low PO2 at high altitude. These distinct characteristics of P. erythrurus are considered to be necessary strategies in metabolic regulation for living at high altitude and may effectively compensate for the negative influence of cold and low PO2.
Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China.
Xiaolong
X
Tang
Ying
Y
Xin
Huihui
H
Wang
Weixin
W
Li
Yang
Y
Zhang
Shiwei
S
Liang
Jianzheng
J
He
Ningbo
N
Wang
Ming
M
Ma
Qiang
Q
Chen
D000064:Acclimatization / Q000235:genetics / Q000502:physiology*; D000531:Altitude; D000818:Animals; D001278:Atractyloside / Q000031:analogs & derivatives / Q000494:pharmacology; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D006153:Guanosine Diphosphate / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008116:Lizards / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D047495:PPAR gamma / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics
D047495:PPAR gamma; D014157:Transcription Factors; C111264:peroxisome-proliferator-activated receptor-gamma coactivator-1; D006153:Guanosine Diphosphate; D001278:Atractyloside; D007770:L-Lactate Dehydrogenase; D002950:Citrate (si)-Synthase; C003853:carboxyatractyloside