102 



The Endocrine Organs 



they consider this was due to causes incidental to the operation (shock, 

 haemorrhage, infection). Those that survived showed none of the symptoms 

 above described as characteristic of apituitarism. But in view of the 

 results of clinical observations on the effects of destructive disease of the 

 pituitary, it must be regarded as doubtful whether the removal of the gland 

 has been as complete in these cases as in those described by Paulesco and 

 Cushing, the operative method employed by whom seems less open to objec- 

 tion than that in which the gland is reached through the basi-sphenoid. 



Effects of Partial Removal and Injury 



The results of lesions which involve only partial removal are even 



more interesting than those in 

 which the extirpation is complete 

 and the symptoms more acute. 

 The most striking effects are ob- 

 tained in young animals. Re- 

 tardation of growth after hypo- 

 physectomy has been described 

 by various authors, and that this 

 is a characteristic of diminished 

 amount of pituitary substance 

 and concomitant diminished 

 secretion of autacoids by the 

 gland has been established by the 

 experiments of Cushing and of 

 Biedl. The work of Aschner, 

 which has already been alluded 

 to, also obviously has an im- 

 portant bearing upon this point, 

 although Aschner himself be- 

 lieves that in most of his operations the removal was complete and that 

 the condition was one of apituitarism. The retardation in development 

 shows itself in a general diminution in size, in the ossification process, 

 which is imperfect, and in the sexual organs, which long retain their 

 infantile condition. Mental dullness has also been generally noted. 



In spite of retardation in development, there is a marked tendency to 

 fat formation, so that the actual weight of the operated animal may exceed 

 that of the control. Even in adult animals a tendency to obesity is a 

 characteristic feature after partial hypophysectomy. Accompanying this 

 tendency, and possibly acting as a causative agent, is a high tolerance for 

 sugars, the limit of alimentary glycosuria being markedly raised. This 

 is the contrary effect to that produced by injection of posterior lobe 

 extract, and is doubtless the result of deficiency of posterior lobe secre- 

 tion, which in Cushing's opinion "is essential to effective carbohydrate 

 metabolism." 



Fig. 70. — Twelve-nionths-old hypophysectomised 

 dog (left) and control of same litter (right). 

 (Aschner.) The operation was performed at 

 eight weeks. 



