METABOLISM AND THE PARS GLANDULARIS 



How the substance afFecting fat-metabolism is related to 

 the substances affecting the metabolism of carbohydrates 

 (either by increasing the liberation of epinephrine or by some 

 more direct mechanism) is not known; however, it seems 

 probable that the effects are closely related. Rietti (1934) 

 produced the most striking change in the excretion of ketone 

 bodies in pancreatectomized dogs; after both thyroidectomy 

 and pancreatectomy his extract still caused an increase in the 

 hyperglycemia but no increase in the ketonuria. On the other 

 hand, the substance obtained by Funk from the urine was 

 equally effective in normal or thyroidectomized rats. Extracts 

 may cause a fall in the concentration of hepatic glycogen with- 

 out any change (Deuel), or with an increase (Steppuhn), or 

 with a diminution (Schultze, 8-12 per cent change) in the 

 concentration of liver-fat. As Deuel pointed out, the fat-me- 

 tabolism hormone seems to oppose rather than to aid the me- 

 tabolism of fat perhaps by interfering with the metabolism of 

 carbohydrates. He found that, under appropriate conditions, 

 the ketonuria produced by the injection of anterior-lobe ex- 

 tract into rats could be prevented by the administration of 

 glucose.^-' 



THE EFFECTS OF EXTRACTS OF THE PARS 



GLANDULARIS ON THE METABOLISM OF 



PROTEINS^'' 



The effects of hypophysectomy on the metabolism of pro- 

 teins has been considered already (chap. ii). Hypophysecto- 

 mized animals, such as the dog, may excrete less nitrogen 



" Epinephrin, e.g., causes a ketosis probably by interfering with the combustion 

 of carbohydrate. 



^^ Funk's extract (obtained from urine) produced, after a single injection, a 

 greater ketonuria in rats on a low-fat diet than in those on a high-fat diet. Gaebler 

 (1935) observed an increase in the rate of fat-oxidation in thyroparathyroidecto- 

 mized dogs which had received two injections of anterior-lobe extract provided that 

 the diet contained an appropriate amount — but not too much — carbohydrate. 



^■* Including creatine-creatinine metabolism. 

 [297] 



