Freeze tolerance in the frog, Rana sylvatica
Experientia , Volume 40 - Issue 11 p. 1261- 1262
Wood frogs survive extracellular freezing at moderate subzero temperatures (-4°C) for at least 11 days. Freezing survival is aided by the accumulation of high concentrations of glucose as a cryoprotectant in blood and tissues. Glucose production was accompanied by a rapid decline in liver, but not muscle, glycogen levels suggesting that liver is the organ controlling cryoprotectant synthesis.