Literaturdatenbank
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Storey, K. B., Layne, J. R., Cutwa, M. M., Churchill, T. A., & Storey, J. M. (1993). Freezing survival and metabolism of box turtles, terrapene carolina. Copeia, 1993(3), 628–634.
Added by: Sarina Wunderlich (23 Aug 2008 14:57:16 UTC) |
| Resource type: Journal Article BibTeX citation key: Storey1993 View all bibliographic details  |
Categories: General Keywords: Emydidae, Habitat = habitat, Nordamerika = North America, Physiologie = physiology, Schildkröten = turtles + tortoises, Terrapene, Terrapene carolina Creators: Churchill, Cutwa, Layne, Storey, Storey Collection: Copeia |
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| Abstract |
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Adult eastern box turtles Terrapene carolina carolina from Ohio readily recovered after 44 h of freezing exposure at -2 C. During thawing at 25 C, motor responses resumed in a sequence of increasing complexity with a reflex twitch in response to poking seen after 1.2 +- 0.5 h, coordinated retraction of the limbs after 2.0 +- 0.18 h, and voluntary locomotion after 2.7 +- 0.4 h. Turtles dissected immediately after freezing exposure had ice in body cavities and surrounding skeletal muscles in limbs. Analysis of putative cryoprotectants in serum and seven organs showed that all organs accumulated glucose during freezing. Net glucose accumulations of 6-20 mu-mol/g wet weight represented 4-22-fold increases; the highest glucose levels were in liver, heart, and serum. Liver glycogenolysis was identified as the source of the glucose; this was supported by both metabolite (a 62.5-fold increase in the precursor glucose-6-phosphate) and enzyme (the percentage of glycogen phosphorylase in the active a form rose from 21.3-57.5%) responses to freezing. Freezing exposure also caused an increase in lactate levels in serum and four organs, but glycerol ( lt 2 mu-mol/g), sorbitol ( lt 0.3 mu-mol/g), and free amino acid levels in organs were unchanged. Both the low levels of putative cryoprotectants and measurements of serum osmolality, 244 +- 4.3 and 315 +- 15.4 mOsmol/l for control and freezing exposed turtles, indicated that box turtles can endure freezing without an accumulation of large pools of low molecular weight cryoprotectant.
Added by: Sarina Wunderlich |