HYPOPHYSEAL MORPHOLOGY 



203 



rats after estrogen administration, large 

 numbers of mitoses are observed in the 

 chromophobes and granulated acidophils, 

 an effect which is probably due to the ac- 

 tion of the injected estrogen on these cells. 

 The number of mitotic figures induced by 

 this single injection of estrogen in the ado- 

 lescent female rat is much greater than 

 that observed after similar doses in adult 

 animals and indicates that a proliferation of 

 cells of the acidophil class occurs in the fe- 

 male rat hypophysis at the time of matura- 

 tion. Baker and Everett ( 1947) found by ac- 

 curate measurements of mitotic index that 

 stimulation of mitoses in acidophil cells 

 after estrogen administration is greater in 

 innnature female rats than in the mature 

 animal. 



E. THE ACTIVE BREEDING PHASE 

 IN THE FEMALE 



The relation between hypophysis and 

 gonad during the breeding phase is quite 

 different from that before maturation. In the 

 rat, with its short estrous cycle, there is a re- 

 current discharge of gonadotrophins at each 

 ovulation and this maintains the gondaotro- 

 phic hormone content at a low level. In ac- 

 cordance with this the gonadotrophs whether 

 studied by the glycoprotein staining reac- 

 tion or by the Mallory staining reaction are 

 inconspicuous because of the low content 

 of specific granulation. There is during the 

 diestrum an accumulation of specific granu- 

 lation (Catchpole, 1949; Purves and Gries- 

 bach, 1951a). Before the thyrotrophs and 

 gonadotrophs were distinguished, there were 

 observations showing a cyclic change in 

 basophil cells during the estrous cycle. 

 Those by Wolfe and Cleveland (1933a) and 

 Wolfe (1935) revealed a variation of baso- 

 phil cells in their rats which is in exact 

 agreement with the variations of the spe- 

 cific gonadotrophs (Table 3.2). 



The basophil cells observed by Wolfe, 

 which are described as being large, oval, 

 finely granulated, and containing a negative 

 image of the Golgi body in most of the 

 cells, correspond in all details with the LH 

 cells (central gonadotrophs) observed by 

 Purves and Griesbach (1952). 



Cyclic changes in the hypophysis of the 

 dog were described by Wolfe, Cleveland and 



Campbell (1933) who distinguished in tlie 

 pars anterior 4 types of cells, 3 of which 

 contained specific granules. Goldberg and 

 Chaikoff ( 1952a » distinguished 6 cell types 

 of which 4 had specific granules. Type I of 

 Wolfe, Cleveland and Campbell corresponds 

 to the a-cell; their type II, which is selec- 

 tively stained by azocarmine (Hartmann, 

 Fain and Wolfe, 1946) corresponds to the 

 e-cell of Goldberg and Chaikoff. Type III 

 corresponds in the main to the 8-cell, but 

 includes small numbers of cells with a pe- 

 ripheral accumulation of granules which are 

 probably /3-cells. The 8-cells (type III) in- 

 creased in numbers up to 10 per cent at the 

 proestrum and w^ere then well filled with 

 fine purplish stained granules. At the time 

 of estrus the number of 8-cells was at a 

 maximum (12.6 per cent) but at the same 

 time they showed extensive degranulation. 

 The number of 8-cells recognized during the 

 lutein phase of the estrous cycle and during 

 pseudopregnancy was low (2 to 4 per cent), 

 and during the anestrum it was 5 per cent. 

 The variation in number of 8-cells and of 

 the granules in these cells corresponds to 

 what would be expected from a cell type 

 producing FSH, if it is right to assume that 

 this hormone is not secreted during pseudo- 

 pregnancy. Wolfe, Cleveland and Campbell 

 also observed changes in e-cells (type II) 

 which, from a level of 5.8 per cent during 

 the anestrum, rose to 7 per cent at estrus 

 and fell during the later lutein phase of the 

 cycle to 2.5 per cent. At this time they also 

 showed considerable degranulation. Present 

 interpretation of these changes would asso- 

 ciate the changes in the €-cells with the 

 secretion of lactogenic hormone. 



Cyclic changes in cells of acidophil and 



TABLE 3.2 

 (After J. M. Wolfe, Anat. Rec, 61, 321-330, 1935.) 



