216 



METABOLIC HORMONES 



Fig. 5-16. Volume of urine and the micro-equivalents of sodium 

 ions excreted by normal (control) and adrenalectomized (expt) male 

 rats, Rattus, over a 4 hr period after administration of water by 

 stomach pump (roughly 11 ml was given to each rat, according to 

 its size, 1 hr before the record started and again at hour to inhibit 

 ADH secretion). Food was removed 24 hr beforehand. Note the 

 poor water excretion by the adrenalectomized animals (lack of 

 DIURETIC hormone) but their very high output of sodium (lack of 

 ALDOSTERONE, cf. Fig. 5-15). The simultaneous output of potassium, 

 though not shown, was little altered (from Chester Jones, 1957). 



balance can be restored by injection of ACH, particularly aldo- 

 sterone, though corticosterone is also effective (Chester Jones, 

 1957<2). Although hydrocortisone can be present in 30 times the 

 concentration of aldosterone in the blood, the latter is 300 times 

 as potent in controlling the Na+ balance and possibly that of 

 Cl~. It also has an action on the Na"'"/K+ ratio of salts excreted 

 by the sweat and salivary glands (Simpson and Tait, 1955). 



Table 26 shows that the effect of adrenalectomy on the plasma 

 potassium, K+, in rats is opposite to that on sodium. This is in 

 part due to the effect of ion exchange in the distal tubule (Fig. 

 S-\Sa). Sodium loss and potassium retention seem to be major 

 factors in causing the death of adrenalectomized animals, though 

 the former is the more important, since life can be maintained, 

 despite high blood potassium, as long as a high level of sodium 

 chloride is given in the diet. 



