186 CORTEX 



threatens to disturb the normal osmotic pressure of the organ- 

 ism, one might expect the ingested potassium to be retained 

 to compensate for the loss of other electrolytes. Should the 

 amount of potassium ingested not suffice, this ion might also 

 diffuse from the muscles and other tissues into the blood in 

 order to maintain an osmotic balance. Whether or not the 

 loss of potassium from the muscles is responsible for the muscu- 

 lar asthenia and weakness observed in adrenal insufficiency is 

 problematical. It is also possible, of course, that a loss of the 

 normal impermeability of the muscle cells results in the diffu- 

 sion of potassium into the blood. The evidence available, at 

 present, which purports to show that the permeability of the 

 muscles is abnormal in adrenal insufficiency is, however, not 

 valid. The fact that the potassium content of the blood rises 

 during the late stages of insufficiency when little or no food is 

 being ingested would indicate that it, in part, originates from 

 the tissues. In any case, it is plausible to assume that the same 

 tubular injury which makes it impossible for the kidney to re- 

 absorb sodium and chloride efficiently also fails to prevent the 

 diffusion of potassium from the tubules back into the blood. 

 The presence of an abnormal concentration of potassium in 

 the blood will, as we have seen, help to maintain the normal 

 osmotic pressure of the blood. 



The ratio of the sodium to the potassium content of the 

 blood plasma drops to about half of its normal value in adrenal 

 insufficiency. Similarly the ratio of potassium to calcium is 

 increased about one-third. The maintenance of a proper ratio 

 between the above-mentioned electrolytes is of fundamental 

 importance to the organism for any disturbance in these ratios 

 alters appreciably the physicochemical properties of proto- 

 plasmic systems. The alteration of these ratios in adrenal 

 insufficiency is probably secondary to the loss of sodium and 

 chloride through the kidney and a consequence of the main- 

 tenance of an approximately normal osmotic pressure. The 

 resulting disturbed ratios will undoubtedly act deleteriously 



