EFFECT OF ADRENALINE ON PLASMA AND TISSUE CONSTITUENTS 



619 



the chance of returning is a rather small one in view of the large phosphate 

 pool of tissue cells. An escape of the ^^P into the cells will thus reduce 

 the probability of its return from the interspaces into the vascular bed and 

 hence will ultimately accelerate the rate of exodus of ^sp from the plasma. 

 That injected ^^K leaves the plasma at a much more rapid rate than 

 injected 24Na, observed in the earliest experiment of this type (Hahn, etal. 

 1941), and interpreted as due to the large potassium pool orilie tissue 



2400- 



'e2200- 

 E 

 ^2000 H 



c 



o 1600- 



o 1600 - 



E 



° 1400 



a. 



^1200 

 1000- 



u- 



I. 800- 

 ■^ 600 

 "^ 400 

 200 H 



Conrrol rabbit 



— O Adrenoline injected 



n 1 1 1 r 



3 4 5 6 7 



Time in minutes 



Fig. 4. Effect of injection of adrenaline on the rate of extrusion 

 of 22Na from the circulation of the rabbit 



cells in contrast to their restricted sodium pool. Should adrenaline ac- 

 celerate the rate of interchange between the phosphate of the interspaces 

 and that of the tissue cells, this may explain its effect on the rate of 

 exodus of 32P from the vascular bed. Doses of adrenaline as applied by 

 us are known to increase the oxygen consumption (Carr, 1934; Lund- 

 holm, 1949). 



In the case of sodium the interchange between interspaces and tissue 

 cells having a restricted importance only, as the incorporation of Na-* 

 into the skeleton and cartilage, which harbours most of the not extra- 

 cellular sodium, takes some time, adrenaline should not much accelerate 

 the exodus of ^^Na in experiments taking about 1 hour only. 



It is of interest to note that while from the sodium content of the ear 

 cartilage of the rabbit follows an apparent extracellular volume of that 

 organ amounting to 96.67o of its weight, we found 10 min following 

 the injection of radiosodium into the circulation of the rabbit a ^a^a 

 content of the ear cartilage which corresponds to an extracellular space 



