Document Detail


Comparative shell buffering properties correlate with anoxia tolerance in freshwater turtles.
MedLine Citation:
PMID:  17008457     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Freshwater turtles as a group are more resistant to anoxia than other vertebrates, but some species, such as painted turtles, for reasons not fully understood, can remain anoxic at winter temperatures far longer than others. Because buffering of lactic acid by the shell of the painted turtle is crucial to its long-term anoxic survival, we have tested the hypothesis that previously described differences in anoxia tolerance of five species of North American freshwater turtles may be explained at least in part by differences in their shell composition and buffering capacity. All species tested have large mineralized shells. Shell comparisons included 1) total shell CO2 concentration, 2) volume of titrated acid required to hold incubating shell powder at pH 7.0 for 3 h (an indication of buffer release from shell), and 3) lactate concentration of shell samples incubated to equilibrium in a standard lactate solution. For each measurement, the more anoxia-tolerant species (painted turtle, Chrysemys picta; snapping turtle, Chelydra serpentina) had higher values than the less anoxia-tolerant species (musk turtle, Sternotherus odoratus; map turtle, Graptemys geographica; red-eared slider, Trachemys scripta). We suggest that greater concentrations of accessible CO2 (as carbonate or bicarbonate) in the more tolerant species enable these species, when acidotic, to release more buffer into the extracellular fluid and to take up more lactic acid into their shells. We conclude that the interspecific differences in shell composition and buffering can contribute to, but cannot explain fully, the variations observed in anoxia tolerance among freshwater turtles.
Authors:
Donald C Jackson; Sarah E Taylor; Vivian S Asare; Dania Villarnovo; Jonathan M Gall; Scott A Reese
Related Documents :
15575247 - Alcoholic ketoacidosis associated with multiple complications: report of 3 cases.
8989967 - Absorbable adams-deweese caval clip: an experimental study.
7328587 - Synthesis and evaluation of ureido- and vinylureidopenicillins as inhibitors of intraru...
811087 - Production of gibberellin-like substances by bacteria and fungi isolated from the roots...
5119777 - N-carbamoyl-2-(p-hydroxyphenyl)glycine from leaves of broad bean (vicia faba l.).
7506667 - Evaluation of the mechanisms underlying the kainate-induced impairment of [3h]dopamine ...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2006-09-28
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  292     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2007 Feb 
Date Detail:
Created Date:  2007-02-02     Completed Date:  2007-03-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R1008-15     Citation Subset:  IM    
Affiliation:
Department of Molecular Pharmacology, Physiology, and Biotechnology, Box G, Brown University, Providence, RI 02912, USA. donald_jackson@brown.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / physiopathology*
Buffers
Carbon Dioxide / blood,  metabolism
Fresh Water
Hydrogen-Ion Concentration
Lactic Acid / metabolism
Minerals / metabolism
Species Specificity
Turtles / physiology*
Chemical
Reg. No./Substance:
0/Buffers; 0/Minerals; 124-38-9/Carbon Dioxide; 50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Myocardial preconditioning against ischemia-reperfusion injury is abolished in Zucker obese rats wit...
Next Document:  Denervation does not change the ratio of collagen I and collagen III mRNA in the extracellular matri...