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

PLoS One. 2013 Aug 7;8(8):e71976. doi: 10.1371/journal.pone.0071976. eCollection 2013.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acclimatization / genetics
  • Acclimatization / physiology*
  • Altitude*
  • Animals
  • Atractyloside / analogs & derivatives
  • Atractyloside / pharmacology
  • Citrate (si)-Synthase / metabolism
  • Energy Metabolism / genetics
  • Energy Metabolism / physiology*
  • Gene Expression
  • Guanosine Diphosphate / pharmacology
  • L-Lactate Dehydrogenase / metabolism
  • Liver / metabolism
  • Lizards / genetics
  • Lizards / metabolism
  • Lizards / physiology*
  • Male
  • Mitochondria, Liver / metabolism
  • Mitochondria, Muscle / metabolism
  • Muscle, Skeletal / metabolism
  • Oxygen Consumption / drug effects
  • Oxygen Consumption / physiology
  • PPAR gamma / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Species Specificity
  • Transcription Factors / genetics

Substances

  • PPAR gamma
  • Transcription Factors
  • peroxisome-proliferator-activated receptor-gamma coactivator-1
  • Guanosine Diphosphate
  • Atractyloside
  • L-Lactate Dehydrogenase
  • Citrate (si)-Synthase
  • carboxyatractyloside

Grants and funding

Research funding was supported by the National Natural Science Foundation of China (No. 31272313 to Q. Chen). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.