Response of Anatolian mountain frogs (Rana macrocnemis and Rana holtzi) to freezing, anoxia, and dehydration: Glucose as a cryoprotectant

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Tarih

2021

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Academic Press Inc Elsevier Science

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

Cryoprotectants play an essential role in the survival of some amphibians in response to different stress conditions such as freezing, anoxia, and dehydration. Glucose is one of the cryoprotectants important for freeze-tolerant frogs. The aim of the present study was to investigate the survival strategies of Anatolian mountain frogs (Rana macrocnemis and Rana holtzi), which are terrestrial hibernators, by examining the changes in glucose and water content in some tissues at subzero temperatures. In the current study, animals were exposed to freezing (-2.5 degrees C), anoxia, and dehydration treatments. During these treatments, all frogs survived. The glucose levels in the plasma, liver, and skeletal muscle and the water content of the tissues were measured during the freezing, anoxia, and dehydration. Changes in body weight were also recorded in both species. During the freezing, a 3.3-fold increase was seen in the blood glucose level of R. macrocnemis (1.35 +/- 0.25 to 4.45 +/- 0.51 mu mol mL(-1)), whereas the blood glucose level of R. holtzi exhibited a 4.5-fold increase (1.90 +/- 0.25 to 8.67 + 2.22 mu mol mL(-1)). In the liver, a 6.7-fold increase was seen in the glucose level of R. macrocnemis (5.66 +/- 0.15 to 38.27 +/- 8.53 mu mol g(-1)) and the increase in R. holtzi was approximately 6.0-fold (2.25 +/- 0.46 to 13.36 +/- 1.32 mu mol g(-1)) during freezing. The liver glucose levels of both species also increased significantly in response to the anoxia and dehydration. In both species, the glucose levels of the skeletal muscle were found to be higher in dehydration than with freezing and anoxia. In conclusion, our results suggest that glucose may be identified as an important cryoprotectant that plays an important role in the survival of Anatolian mountain frogs during extreme conditions.

Açıklama

Anahtar Kelimeler

Cryobiology, Rana macrocnemis, Rana holtzi, Freeze tolerance, Glucose levels

Kaynak

Cryobiology

WoS Q Değeri

Q3

Scopus Q Değeri

Q1

Cilt

98

Sayı

Künye