192 



HYPOPHYSIS AND GONADOTROPHIC HORMONES 



ules were confined to cell^ that were ovoid or 

 spherical. The most conspicuous staining was 

 in cells in the periphery of the pars anterior, 

 especially on the inferior surface and at the 

 anterior margin. In hypophyses which con- 

 tained neither thyrotrophin nor gonado- 

 trophin basophil cells could not be demon- 

 strated by either the glycoprotein reaction or 

 aniline blue. 



These results showed that the different 

 hormones were stored in the granules of dif- 

 ferent cells and that the hormone content 

 was proportional to the granule content. 

 Any staining method which demonstrated 

 the granules would give the same result and, 

 had the Dempsey and Wislocki (1945) sug- 

 gestion that aniline blue stained the hor- 

 mones been followed up, results similar to 

 those obtained by the PAS reaction would 

 have been obtained. The PAS reaction pro- 

 vided a more specific staining for basophil 

 granules; its more important role, however, 

 was the psychologic stimulus it gave to in- 

 vestigations relating staining to hormone 

 content because there was a chemical reason 

 for supposing that this reaction would dem- 

 onstrate the content of thyrotrophin and 

 gonadotrophins. 



Purves and Griesbacli < 1951a) gave the 

 name "thyrotrophs" to the cells whose gran- 

 ules contain thyrotrophin and the name 

 "gonadotrophs" to the cells whose granules 

 contain gonadotrophins. 



Halmi (1951a, b) applied Gomori's 

 (1950) aldehyde-fuchsin to the staining of 

 the i)ars anterior and obtained the dis- 

 tinction between yS-cells and 8-cells that had 

 previously been obtained by Romeis (1940). 

 It was soon established that the ^-cells 

 of the rat pars anterior are thyrotrophs 

 (Purves and (h-iesbach, 1951b; Halmi, 

 1952a). 



Restaining iJroccdincs demonstrate that 

 tbe same cytoi)lasmic granules are revealed 

 by aldehyde-fuchsin, ])hosphotungstic acid- 

 aniline l)lue, and the histochemical reaction 

 for glycoprotein. The specific staining of the 

 thyrotrophs is therefore a specific staining 

 of thyrotrophin-containing granules. In rats 

 wliich have been treated with thyroxine the 

 granulation is reduced to such a low level 

 that the thyrotrophs cannot be demon- 

 strated by any of the staining i)roce(hn'cs 

 (Purves and Griesbach, 1951c; Halmi, 



19511), 1952b). In rats which have been thy- 

 roidectomized there is a rapid discharge of 

 thyrotrophin which reduces the granule con- 

 tent in the cells to a low level. There is 

 simultaneously a marked increase in the 

 number of functioning thyrotrophs and an 

 increase in the size of the individual cells. 

 The total hormone content of the gland is 

 affected in opposite directions by these two 

 effects, and may not be greatly different 

 from normal despite a low concentration of 

 the hormone in the cell cytoplasm. Under 

 these conditions staining by aldehyde- 

 fuchsin is not obtained although the cyto- 

 plasm and the hyaline substance are still 

 stainable by other methods. The thyro- 

 trophs, therefore, after thyroidectomy are 

 easily confused with 8-cells although they 

 are still cleary differentiated from 8-cells 

 by their characteristic shape (Purves and 

 Griesbach, 1951b). 



The specific staining of thyrotrophin-con- 

 taining granules by aldehyde-fuchsin con- 

 stitutes a notable advance in the study of 

 the functional aspects of pituitary mor- 

 phology. The differentiation of thyrotrophs 

 from other cells by Halmi's (1951a) method 

 clarifies not only the study of thyrotrophic 

 function, but also that of gonadotrophic 

 functions in the rat pituitary because the 

 two types of basophils concerned with the 

 secretion of the gonadotrophic hormones ap- 

 pear as 8-cells which can be studied with- 

 out confusion with thyrotrophs. 



It was soon apparent (Purves and Gries- 

 bach, 1952; Si{)erstein, Nichols, Griesbach 

 and Chaikoft', 1954) that the gonadotrophs 

 in the rat pars anterior are of two types. 

 The peripheral gonadotrophs near the sur- 

 face of the anterior lobe and especially con- 

 centrated on the inferior surface and at the 

 anterior border show a consistently different 

 a])pearance from the i)aler rounded cells 

 whicli are scattered throughout the interior 

 and arc the only basophils adjacent to the 

 l)ai's intci'niedia (Fig. 3.9). 



This suggests the hypothesis that one 

 form secretes FSH and the other LH. The 

 central gonadotrophs are the more active- 

 looking cells after castration and during 

 pregnancy. There was therefore a conflict 

 l)etween the at one time current view that 

 after castration the secretion is predomi- 

 nantly follicle-stimulating and the ])roba- 



