212 



HYPOPHYSIS AND GONADOTROPHIC HORMONES 



otrophin resulting from alterations of thy- 

 roid or gonadal function produced by high 

 levels of costicosteroids. The fact that these 

 cells are not hyalinized in myxedema or 

 after castration shows that this is not so. 

 In the present state of knowledge it seems 

 probable that Crooke's cells are actively 

 secreting intermedin, the effects of which 

 are antagonized by corticosteroids. Only 

 occasionally is the Gushing syndrome as- 

 sociated with hyperpigmentation (Ed- 

 munds, McKeown and Coleman, 1958). It 

 can be affirmed that Crooke's cell changes 

 have nothing to do with an increased secre- 

 tion of corticotrophin because they are pro- 

 duced by conditions which cause suppres- 

 sion of corticotrophin secretion. 



h. changes in the purple /3-cells in 

 Addison's disease 



Reports on the human pars distalis in 

 Addison's disease indicate a diminution in 

 the number of basophil cells or at least a 

 scarcity of well granulated basophils 

 (Kraus, 1923, 1926, 1927; Berblinger, 1932; 

 Crooke and Russell, 1935). It is the purple 

 /?-cells which disappear, apparently passing 

 into an inactive state in which they lose 

 their granules. Blue basophils remain ap- 

 parently in a normal state and it is these 

 cells which have been referred to as Crooke- 

 Russell cells. This interpretation is in con- 

 formity with the staining reactions of 

 Crooke-Russell cells reported by Russell 

 (1956) and by Wilson and Ezrin (1954). 

 Presumably both blue /3- and 8-cells are 

 present ; the material at my disposal has not 

 been suitable for differential staining of 

 these cell types. 



In view of the inactivity of the purple 

 /?-cells in Addison's disease, the hyperpig- 

 mentation in this condition must be as- 

 cribed to the intrinsic melanocyte stimu- 

 lating activity of the corticotrophin which 

 is being secreted in excessive amounts. Per- 

 haps it is the effects of this side reaction of 

 corticotrophin which cause suppression of 

 int(n'mcdin secretion in this condition. 



I. THE PHARYNGEAL HYPOPHYSIS 



The pharyngeal hypophysis is a collection 

 of cells found in the submucosa of the pos- 

 terior pharyngeal wall and is a remnant of 



the epithelial stalk of the hypophysis which 

 connects the buccal ectoderm to Rathke's 

 pouch at an early stage of embryonic de- 

 velopment. The pharyngeal hypophysis is 

 found only in man and seems to be con- 

 stantly present (Romeis, 1940) . It is a mass 

 of cells 3 to 4 mm. in length. The cells are 

 mainly small with scanty cytoplasm, but 

 larger chromophobes and occasional acido- 

 phils are present. Basophil cells are ex- 

 tremely rare. 



It has been suggested that the pharyngeal 

 hypophysis can take over some of the func- 

 tion of the sellar hypophysis when the latter 

 is destroyed by disease processes (Tonnis, 

 Miiller, Ostwald and Brilmayer, 1954; 

 Miiller, 1958). This cannot be regarded as 

 established for the residual function may 

 be traceable to pars distalis cells that have 

 escaped destruction. 



The pharyngeal hypophysis is sometimes 

 the site of adenoma formation (Miiller, 

 1958). Erdheim (1926) described a case of 

 acromegaly in which was found an un- 

 altered sellar hypophysis and an acidophil 

 adenoma derived from the pharyngeal hy- 

 pophysis. 



XIV. Electron Microscopy of the 

 Adenohypophysis 



Many cytologic structures are so small 

 that the details of their structure cannot be 

 made out by means of the light microscope, 

 the resolving power of which is limited to 

 about 300 nifi. The limit of resolution of the 

 electron microscope is about 1/1000 that 

 of the light microscope. Because of the low 

 electron density of organic materials and the 

 consequent lack of contrast in thin sections 

 of tissues, the available resolution of the 

 electron microscope for cytologic detail is 

 limited to about 1/50 of that of the light 

 microscope, i.e., about 6 ni/x. This is a 

 big advance, comparable to that produced 

 by the change from the simple hand lens to 

 the compound microscope. 



The most fertile application of electron 

 microscopy in the field of cytology has been 

 the examination of ultrathin sections of 

 tissues fixed in solutions containing osmic 

 acid. Osmic acid has been for many years 

 considered the best fixative for the pres- 

 ervation of fine structure in material exam- 



