Annual variation in glycerol mobilization and effect of freeze rigor on post-thaw locomotion in the freeze-tolerant frog Hyla versicolor.
This study documents post-thaw recovery of jump distance and cryoprotectant mobilization in the freeze-tolerant frog Hyla versicolor over two successive years. Cold acclimated frogs had plasma glycerol levels near 1.0 mM in 2004 but it was nearly 70x higher during 2005. Freezing of frogs induced nearly identical levels of plasma glycerol (ca. 177 mM) during 2004 and 2005. Plasma glucose was only mobilized upon somatic freezing, with averages ranging between 21 and 36 mM. Control jump distance showed no difference between the two years of the study. The post-thaw jump response was identical during the first 2 years despite large differences in glycerol mobilization between these 2 years. Recovery proceeded much faster in 2005 when frogs mobilized glycerol prior to freeze exposure. Frogs were more impaired in their locomotion performance during the initial stages of recovery period when they were frozen at a lower temperature (-3 vs. -1.5 degrees C) but they eventually recovered. Moderate lengthening of the freeze duration (3 vs. 7 days) with the 2004 collection group did not affect recovery of jump distance when frogs were frozen at -1.5 degrees C. Hence, postfreeze impairment of locomotion is dependent of the intensity of the freeze temperature but it is a reversible process that is mitigated when glycerol is more freely distributed to body tissues.
Layne
Jack R
JR
Department of Biology, Slippery Rock University, Slippery Rock, PA 16057, USA. jack.layne@sru.edu
Stapleton
Michael G
MG
D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D001001:Anura / Q000378:metabolism / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D003451:Cryoprotective Agents / Q000378:metabolism*; D005615:Freezing; D005990:Glycerol / Q000097:blood / Q000378:metabolism*; D007087:Illinois; D008124:Locomotion / Q000502:physiology*; D008297:Male; D013997:Time Factors
D001786:Blood Glucose; D003451:Cryoprotective Agents; D005990:Glycerol
Am J Physiol. 1987 Aug;253(2 Pt 2):R292-7
3618830
J Exp Zool. 1989 Feb;249(2):133-7
2723602
Physiol Biochem Zool. 2003 May-Jun;76(3):331-8
12905119
Science. 1982 Feb 5;215(4533):697-8
7058335
Biol Bull. 1949 Apr;96(2):140-61
18120626
Comp Biochem Physiol A Comp Physiol. 1986;83(4):613-7
2870854
Physiol Zool. 1997 Mar-Apr;70(2):158-66
9231388
Nature. 1997 Sep 25;389(6649):343-4
9311774
Am J Physiol Regul Integr Comp Physiol. 2007 Jan;292(1):R544-55
16973932
Am J Physiol. 1991 Jul;261(1 Pt 2):R134-7
1858939
J Exp Zool. 1999 Feb 15;283(3):221-5
9933936
J Comp Physiol B. 1994;164(4):316-20
7962786
J Exp Biol. 1995;198(Pt 12):2569-73
9320497
J Exp Zool. 1992 Apr 1;261(4):373-8
1569408
J Exp Biol. 2005 Nov;208(Pt 21):4079-89
16244167
Am J Physiol. 1991 Dec;261(6 Pt 2):R1549-53
1750578
J Physiol. 1971 May;215(1):95-102
5579685
J Exp Zool. 1998 Feb 1;280(2):197-201
9433805
J Exp Zool. 2001 Jun 15;290(1):1-5
11429758
J Exp Biol. 2003 Aug;206(Pt 16):2859-67
12847129