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“The accumulation of high levels of low-molecular-weight solutes (polyhydric alcohols, saccharides [e.g., the sugar glucose]) provides cryoprotection to freeze-tolerant animals by minimizing, via colligative [binding] effects, the percentage of body water converted to extracellular ice and the extent of cell volume reduction…[F]reeze-tolerant frogs respond to ice formation in peripheral tissues by synthesizing large amounts of glucose in the liver and rapidly distributing the sugar throughout the body…Proton magnetic resonance imaging of freezing and thawing in whole frogs showed a new adaptive effect of the very high glucose levels in core organs; during thawing, organs such as liver and heart melted first, allowing recovery of their vital functions to begin while the rest of the frog thawed.” (Storey 1997:319)

“Seminal studies of freeze tolerance in woodland frogs have documented their efficacious system for copiously mobilizing glucose or glycerol in direct response to corporal freezing (Schmid, 1982; Storey and Storey, 1988). Cryoprotectant is chiefly derived from glycogen that accumulates in liver, representing up to 20% of organ mass, during late summer and autumn. Triggered by ice nucleation, its synthesis and export to other tissues proceeds rapidly, with concentrations in blood and core organs ultimately reaching 100–250 mmol l⁻¹. Such levels are readily tolerated by these frogs, but would be deleterious in endotherms. Upon thawing, cryoprotectant is returned to the liver and reconverted to glycogen; reabsorption of glucose in the urinary bladder assists this process and limits the excretory loss of this valuable solute (Costanzo et al., 1997a).” (Costanzo and Lee 2013:1965)