BLOOD CHEMISTRY 187 



on many organs and may be responsible for their dysfunction 

 in adrenal insufficiency. For example, the cardiac arrhythmias 

 often observed in terminal stages of adrenal insufficiency may 

 be attributed to the high potassium content of the blood and 

 the low potassium-calcium ratio. 



ANIONS 



Of the blood anions, the concentration of chloride is most 

 markedly affected as might be anticipated from the changes 

 occurring in the sodium concentration already described. 

 However, the loss of blood chloride is not quantitatively so 

 great as that of the sodium loss (cf. Figure 11). The relative 

 preponderance of the loss of sodium over that of the chloride 

 results in a decrease in the bicarbonate concentration of the 

 blood and a disturbance in the normal acid-base equilibrium. 

 The inorganic phosphate and sulphate are also increased but 

 this increase is usually not prominent except in the later stages 

 of insufficiency. 



The kidney normally maintains the hydrogen ion concen- 

 tration of the blood at a constant value. When its function is 

 disturbed in adrenal insufficiency, this control is inadequate 

 and we find a marked disturbance of the acid-base equilibrium 

 of the blood. This disturbance is marked by a fall in the pH 

 of the blood (cf. Figure 11) accompanied by a decrease in the 

 bicarbonate content and carbon-dioxide combining power of 

 the blood. There is thus an acidosis in adrenal insufficiency 

 which is probably responsible in part for the hyperpnoea 

 observed in the late stages of insufficiency. 



THE MECHANISM OF THE OBSERVED CHANGES IN THE BLOOD 

 CHEMISTRY 



The osmotic pressure of the blood and tissues of mammals 

 is maintained with a high degree of constancy thus affording 

 the organism a "milieu interieure" of constant colligative com- 

 position. The osmotic pressure readily adjusts itself, by rapid 



