ISOLATED PERFUSED LIVER— BRAUER 

 I.O 



241 





0.5 - 



Fig. 5. 



O 0.5 I.O 



RELATIVE BILE FLOW RATE 



(8390= 1.00 ) 



-Relation between bile flow and BSP extraction efficiency (as fraction of ESP in blood 

 removed by liver in one passage) at temperatures below 39° C. 



Summary. 1. The effects of hypothermia upon the functioning of the isolated 

 perfused rat Hver have been studied. 



2. Hemodynamic changes due to coohng of this preparation appear to be con- 

 fined substantially to consequences of the increased blood viscosity. 



3. Chromic phosphate colloid uptake by the liver is slowed by cooling. Tiie rela- 

 tions appear to fit the Arrhenius equations with an activation energy of 15,400 cal. 



4. Cooling results in lowering of perfusate glucose levels relative to those at 

 38° C. There is evidence of a minimum around 32° C. 



5. Bile flow is slowed in the hypothermic liver. Between 38° C. and 17° C. the 

 values can be described by the Arrhenius equation with an activation energy of 

 33,900 cal. At 30-32°, and at 17° C. this fall of bile flow is generally reversible, 

 while at 25° C. a significant fraction of non-recovering preparations were seen. 

 Some detailed changes in bile flow recovery, choleresis, and bile composition have 

 been presented. Decreased dependence of bile flow upon blood flow at slow per- 

 fusion rates has been demonstrated in the hypothermic liver. 



6. The effect of hypothermia upon uptake and excretion of sodium sulfobromo- 

 phthalein disulfonate (BSP) by the liver has been discussed. Changes consist in 

 some slowing of initial dye extraction, premature evidence of saturation of the up- 

 take mechanism, normal bile BSP concentrations but delayed excretion of the dye 

 due to retardation of bile flow. 



7. These results have been discussed from the point of view of their bearing 

 upon the clinical applications of hypothermia and upon the physiology of the 

 hypothermic homeotherm. 



