Jane A. Russell ^21 



the two hormones. The basis of this statement I should like to discuss in 

 some detail. 



First, a major stumbling block in the interpretation of the adrenal-pituitary 

 relationship as a strictly trophic one, mainly centered on gluconeogenesis, has 

 been the different effects of the two glands on nitrogen metabolism. It is true 

 that a diminution in protein breakdowai is one of the effects of adrcnalectomv 

 and that cortical extracts greatly increase nitrogen excretion at the same time 

 that they increase glycogen production. These effects, however, are not at all 

 similar to those related to the anterior pituitary. Lee^ and others have shown 

 clearly that in hypophysectomized animals, a short time after operation, there 

 is a greater loss of nitrogen and a smaller loss of fat than in normal rats on the 

 same food intake. That is, the protein stores seem drawn upon more readily 

 rather than less readily in hypophysectomized animals. The relationship of 

 the length of time after operation at which stich observations are made, to 

 the nitrogen excretion rates found, has not always been recognized. Evidently, 

 at a time sufficiently long after liypophysectomy, adrenal cortical atrophy may 

 reduce the rate of nitrogen excretion to normal or subnormal values, such as 

 have also been reported in hypophysectomized animals. 



In comparing APE and cortical hormones, in their effects on nitrogen 

 metabolism, a like difference is encountered. That is, APE in normal or hy- 

 pophysectomized animals always has an anabolic rather than a catabolic effect, 

 decreasing nitrogen excretion and the free nitrogen of the body, and increas- 

 ing protein deposition. Even in adrenalectomized rats, APE diminishes nitro- 

 gen excretion, as Harrison and Long^'' showed. The effects of APE on nitrogen 

 excretion are also evident in phlorizinized dogs, where gluconeogenesis is 

 proceeding at a high rate and where one wotdd expect nitrogen excretion to 

 be increased rather than decreased, if tlie APE acted similarly to cortical hor- 

 mone.*' Thus, the adrenal cortical and pituitary hormones seem to have differ- 

 ent and opposite effects on nitrogen metabolism as such. Only under certain 

 special conditions, as after pancreatectomy, is there in hypophysectomized 

 animals a marked diminution in nitrogen excretion whicli can be attributed 

 to a decline in gluconeogenesis as a residt of the adrenal insufficiency. 



Another difference has been observed between the effects of adrenal and 

 pituitary extracts which may or may not still be evident when further ^vork 

 has been done: APE, easily and in almost every instance attempted, can be 

 shown to increase liver fat deposition and ketone production in normal ani- 

 mals, btu cortical hormones have not been observed to have tliese effects even 

 when massive doses were given. In these circumstances, it wotdd be extraordi- 

 nary if the action of APE in these respects were pmely a result of adrenocoriico- 

 trophic activity. 



Turning again to carbohydrate metabolism, differences also betw^een the 

 effects of liypophysectomy and adrenalectomy become apparent on close in- 

 spection of the data available. The loss of muscle glycogen in fasting is much 



