Postfreeze O2Consumption in the Wood Frog (Rana sylvatica)

Abstract

Abstract Freeze-tolerant frogs experience marked changes in their cellular chemistry as a result of internal freezing, forcing them to incur metabolic costs that are likely remedied upon thawing. This study measured levels of O2 consumption in Rana sylvatica after freezing for one and seven days at −1.5 C and thawing at 5 C. Oxygen consumption was measured 4, 8, and 28 h after the onset of thawing. Following a one-day freeze, frogs had a 30% lower O2 consumption value after 4 h into the recovery than their prefreeze rate. After the seven-day freeze, the O2 consumption of frogs was nearly as low (−25%) at 4 h, but the reading at 8 h was more than 40% above the control level. Frogs had O2 consumptions equivalent to the control at 28 h following both treatments. Low rates of O2 consumption early in postfreeze recovery corresponds to depressed systemic functions in frogs, and the level of O2 consumption at 8 h following the seven-day freeze was possibly linked to disturbance of the cellular environment.