REGULATION OF GROWTH 



weight of both fetuses and mother by administering certain 

 growth-promoting extracts to pregnant rats. Creep (1936) 

 studied the replacement value of pituitary grafts inserted into 

 the sella of rats of both sexes immediately after hypophysec- 

 tomy, which was performed when the animals were four 

 weeks old. He obtained partial replacement in about three- 

 fourths of the animals (5 males and 32 females), in that 

 growth occurred but did not proceed beyond one-half to two- 

 thirds the normal adult level. The performance of the sexual 

 glands was often essentially normal and will be discussed in 

 chapter iii. 



Especially among clinicians there has always been con- 

 siderable interest in the changes in bones and joints attrib- 

 uted to alterations in the secretory activity of the anterior 

 pituitary. Recently Coryn (1936) has reviewed from a clin- 

 ician's viewpoint the etiological relationship between dis- 

 eases of bones and joints and changes in the endocrine glands. 

 He concluded that pituitary hyperfunction — e.g., oxyphil 

 adenoma of acromegaly — accelerates cellular proliferation and 

 only in this way affects endochondral osteogenesis. He de- 

 nied that any secretion of the normal or abnormal anterior 

 pituitary alters hyaline cartilage or causes hypertrophy of 

 cartilage cells or calcification of osseous tissue. Also, he be- 

 lieved that ankylosing or deforming arthritides do not result 

 from a disturbance of pituitary function, contrary to experi- 

 mental and clinical observations of others. Silberberg (1936), 

 as well as Silberberg and Silberberg (1936-37), recently have 

 studied the changes in the bones and joints of guinea pigs re- 

 ceiving daily injections of an acid extract of the anterior 

 pituitary of the ox for 1-20 weeks. The authors concluded 

 that it is thus possible to produce changes in the joints and in 

 the chondro-osseous junctions of the ribs resembHng acro- 

 megalic arthropathia and acromegalic rosary. Also, they 

 found that callus-formation was delayed by the administra- 

 tion of the extract. All these changes were equally or more 

 pronounced in thyroidectomized guinea pigs. The reader is 



[37] 



