HYPOPHYSEAL MORPHOLOGY 



193 



bility that the hormone secretion during 

 pregnancy is predominantly luteinizing. 

 Af cer a year of investigation it was realized 

 that the solution lay in getting rid of one of 

 the hormones. 



Treatment of the adult female rat with 

 testosterone propionate had been shown to 

 increase the gonadotrophin content of the 

 hypophysis and to produce a gland which 

 contains FSH without any admixture of LH 

 (Laqueur and Fluhmann, 1942; Greep and 

 Chester Jones, 1950). 



Purves and Griesbach ( 1954) found that 

 in female rats treated with 250 fxg. of testos- 

 terone daily for 1 week there was a large 

 increase in the numbers of gonadotrophs of 

 both types which could be stained by the 

 glycoprotein reaction. After 3 weeks treat- 

 ment, the pale central gonadotrophs were 

 found diminished in size and showed signs 

 of diminishing activity. After 4 weeks treat- 

 ment, the central gonadotrophs had prac- 

 tically disappeared whereas large numbers 

 of the peripheral type with a strong cyto- 

 plasmic glycoprotein storage remained. 

 These peripheral gonadotrophs did not seem 

 to be actively secreting because the cells 

 themselves were small. 



These observations seem to indicate with 

 certainty that the peripheral type of gona- 

 dotroph is exclusively the site of formation 

 and storage of FSH, whereas the central 

 type is probably concerned with the forma- 

 tion and storage of LH. 



It has not yet been possible to obtain rat 

 hypophyses containing LH without FSH. In 

 glands containing large amounts of LH 

 there are always large numbers of richly 

 granulated central gonadotrophs and there 

 is no reason to think that the granules of 

 these cells contain any other hormone. 



The cells that secrete and store within 

 their granules FSH are called FSH cells; 

 the cells that secrete and store within their 

 granules LH are called LH cells. 



As yet, no consistent staining difference 

 between the FSH granules and the LH gran- 

 ules has been obtained. The Wilson and 

 Ezrin (1954) technique differentiates be- 

 tween thyrotrophs and gonadotrophs, the 

 former being PAS-red whereas the latter 

 tend to be PAS-purple. The granules of the 

 thyrotrophs have little affinity for acid dyes 

 and do not take up either the orange G or 



methyl blue applied as counterstains to sec- 

 tions which have first been stained by the 

 PAS reaction. Their color is therefore a ma- 

 genta red. Cells with a strong affinity for 

 acid dyes take up orange G and hold it 

 firmly. Strongly acidophilic basophils (am- 

 phophils) of this kind are found among the 

 /3-cells of the human pars distalis; they ap- 

 pear brick-red after the Wilson and Ezrin 

 staining method, the color resulting from the 

 addition of orange G to the PAS color. These 

 cells are also called PAS-red by Wilson and 

 Ezrin. The difference in the two shades of 

 red is visible in Figures 1 and 2 of Wilson 

 and Ezrin's (1954) paper. In basophil cells 

 with an intermediate degree of acidophilia 

 the orange G which is taken up first is dis- 

 placed more or less rapidly by methyl blue 

 in the next step of the procedure. These cells 

 therefore appear purple. The gonadotrophs 

 of the rat have an intermediate degree of 

 acidophilia and may be stained PAS-purple, 

 but the colors obtained are not independent 

 of the amount of granulation present. In this 

 technique there is a tendency for strongly 

 granulated cells to retain the orange G 

 longer and to appear PAS-red whereas in 

 lightly granulated cells the orange G is more 

 rapidly replaced by methyl blue and the 

 cells appear PAS-purple. The color differ- 

 entiations obtained by Rennels (1957) and 

 by Hildebrand, Rennels and Finerty (1957) 

 resulted from this effect. In the normal rat 

 the FSH cells are more densely granulated 

 than the LH cells and can be stained PAS- 

 red while the LH cells are stained PAS-pur- 

 ple, but when densely granulated LH cells 

 appear in long term castrates they too are 

 PAS-red. Ten days after castration when 

 both FSH cells and LH cells are only 

 lightly granulated both stain PAS-purple. I 

 have not found any color differentiation be- 

 tween FSH cells and LH cells containing a 

 similar amount of granulation. The conclu- 

 sions of Hildebrand, Rennels and Finerty 

 concerning the distribution of FSH cells and 

 LH cells are therefore not likely to be cor- 

 rect. 



Despite the absence of specific staining, 

 the granules of FSH cells and LH cells can 

 be shown to be different by solubility tests. 

 I have made a considerable number of tests 

 of this kind. The best results have been 

 ol)tained by perfusion of long term castrate 



