HYPOTHERMIA AXD KIDNF.Y— AXDJUS 



215 



Sodium excretion was recorded with injected tracer sodium (Na-') by can- 

 nulating the bladder and making continuous kymograph tracings of tlie radioac- 

 tivity of tile (luttlowing urine. The lowest temperature reached in these experiments 

 w'as 0° C. Sinn'lar experiments were ])erfornied on a hibernating mammal, the 

 ground squirrel ( Cittelus cittelus). 



The excretion (»f urine continues in the rat until bodv temperatures below 18° C. 

 are reached. ^Moreover, at temjjeraturc's <>f alxnU 20-23° C. an increased urinary 

 output has been often recorded ( Andjus and Moiel, 1952). Similar results were 

 obtained in ground sciuirrels (artificially cooled in the same manner), except that 

 the temperatiu'e limit for diuresis mav reach as low as 7° C. of bodv temperature 

 (fig. 1 ). The maximal intensity of osmotic diuresis as influenced by the level of 

 hvpothernn'a in rats and ground scjuirrels is shown in figure 2. 





2.2 



2. OI- 

 LS 

 1.6 

 1.4 

 1.2 

 1.0 



0.8 



0.6 



0.4 



0.2 



Lrl 



36 



29-31 21-23 16-18 

 DEG C 



8-1 



Fig. 2.— Maximal intensity of osmotic diuresis after an intravenous injection of 2 ml. of a 

 50 per cent glucose solution into rats (white bars) and ground squirrels (black bars). 



