THE PITUITARY BODY 



Zondek (1937) concluded that the secretion of growth-pro- 

 moting hormone does not influence the growth of a sarcoma 

 due to benzpyrene; for the tumor grew no better in normal 

 rats than in rats dwarfed because of the injection of large 

 doses of oestradiol benzoate. 



Druckrey (1936) believed that pituitary gonadotropic hor- 

 mone inhibits tumor-growth in the rat. As malignant neo- 

 plasms he used the Flexner-Jobhng carcinoma and the Jensen 

 sarcoma. Shortly after castration, tumor-growth appeared 

 to be unusually rapid. Later, however (4-6 months after 

 castration), when the gonadectomized animal's pituitary 

 contains and secretes the maximum amount of gonadotropic 

 hormone, inhibition and even failure of tumor-growth ap- 

 peared. Largely from this finding Druckrey reached the con- 

 clusion stated above. 



Both recent and older observations permit the drawing of 

 only Hmited conclusions as to the control of the growth of 

 neoplasms by the anterior pituitary. If there is a complete 

 pituitary deficiency, the initiation of neoplastic growth is 

 more difficult; if the deficiency is produced after neoplastic 

 growth is under way, further growth may take place at a 

 slower rate. Certainly the pituitary appears not to be an im- 

 portant regulator of cellular proliferation in tumors. The 

 conclusion of Engel — that pineal extract inhibits the growth 

 of a carcinoma by acting on the pituitary — as well as the in- 

 ference of Druckrey — that the growth of a sarcoma or car- 

 cinoma is inhibited by the secretion of gonadotropic hor- 

 mone — hardly deserve acceptance without data from more 

 complete experiments. 



The assay of growth-promoting extracts. — Several matters of 

 technic must be mentioned in connection with the assay of 

 growth-promoting extract. Evans, Pencharz, and Simpson 

 (1935) pointed out that crude rather than purified extracts 

 seem to have more certain efi^ects and may be active if given 

 to animals no longer responding to a purified extract. Also, 

 Mortimer (1937) found "resistance" appeared later toward 



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