Insights into kidney function during recovery from anoxia in the painted turtle (1099.2)

Western painted turtles (Chrysemys picta bellii) are well-known for being able to survive anoxia for 120 days at 3°C and tolerate plasma lactate concentrations approaching 200 mM. Given that the turtle becomes hyperglycemic and accumulates lactate during anoxia, the potential to exceed the renal transport maxima for these metabolites exists. Here we assessed the role of the kidney during six hours of anoxia at 20°C and 39 hours of recovery from anoxia. Turtles received both subclavian artery and cloacal catheters for continual monitoring of plasma and urine metabolites. Our hypothesis that kidney function would decline in tandem with arterial PO2 was supported, as urinary flow rate decreased significantly by more than 90%. During the first half of recovery, there was significant appearance of lactate and glucose in the urine; the renal transport maxima for these metabolites were likely exceeded. The excretion of lactate during recovery, though energetically wasteful, may help to relieve the lactic acidosi...