178 



HYPOPHYSIS AND GOXADOTROPHIC HOPtMOXES 



method in the rostral zone of the pars dis- 

 talis of the fowl to be basophils because 

 their granules are intensely stained by the 

 PAS reaction. Of different significance are 

 the definite but relatively weak colorations 

 observed in the carminophil cells of the 

 dog (Purves and Griesbach, 1957a), and 

 frog (Ortman, 1956a). The amount of color 

 formed must be considered in relation to 

 the amount of protein present. In the fully 

 granulated acidophil cell there is a large 

 amount of protein. With close packing of 

 the granules, as much as 50 per cent of the 

 cytoplasmic space can be occupied by solid 

 protein granules. The amount of specific 

 protein in basophil cells is usually very 

 much less. Any nonspecific staining of pro- 

 teins, such as by a weak iodine solution, or 

 by the methods used for staining paper 

 electrophoresis strips, will show the high 

 protein content in the fully granulated 

 acidophil. Calculations based on the color 

 produced by PAS in the mixed proteins of 

 blood plasma (approximately 7 per cent 

 solution of protein containing 1 per cent of 

 sugar by weight) make it evident that ciuite 

 a strong color would be produced in acido- 

 phil cells if there were but one reacting 

 group per molecule of protein. It is only 

 when the color is intense in relation to the 

 amount of protein reacting that the pres- 

 ence of many reacting groups and, there- 

 fore, probably the presence of polysaccha- 

 ride, may be inferred. The color produced in 

 the granules of carminophil cells is not of 

 this intensity. 



In order to resolve the doubt concerning 

 the significance of moderate PAS colora- 

 tions in heavily granulated cells, Purves 

 and Griesbach (1956) used a jireliminary 

 buffer extraction before fixation and found 

 that the carminophil granules in the dog 

 were insoluble, and were still stainable by 

 PAS after extraction at pH 7.5, a treatment 

 that dissolved all the basophil granules. 

 They, therefore, defined basophil granules 

 as granules containing soluble glycopro- 

 teins. This definition enables one to bypass 

 the question 'Ts the PAS reaction in car- 

 minophil granules sufficiently strong to in- 

 dicate the presence of glycoprotein?", the 

 answer to which is a matter of opinion, and 

 to substitute for it a practical solubility test 

 which is easy to carrv out and intevDi'ct. 



When a sensitive PAS sec[uence is used^ 

 acidophil cells generally show a weak color 

 which is easily masked by counterstaining 

 (Fig. 3.7). The cytoplasm of chromophobes 

 shows a similar weak coloration; against 

 this background the acidophils may appear 

 to be unstained. The granules of the car- 

 minophil cells of the sheep, dog, frog, wal- 

 laby (Ortman and Griesbach, 1958) , and 

 cat (Herlant and Racadot, 1957), give re- 

 actions distinctly stronger than this. The 

 observation of Pearse (1951) that the car- 

 minophil cells of the rabbit do not contain 

 glycoprotein does not exclude the possibility 

 of a weak reaction in this species, because 

 he used the Hotchkiss (1948) modification 

 of the PAS sequence, which suppresses weak 

 reactions and is allegedly more specific for 

 glycoproteins. 



Herlant and Racadot inferred that the 

 carminophil cell in the cat was a basophil, 

 but because the color produced by the PAS 

 reaction is weak compared to that in typical 

 basophils, I would regard this as a case to 

 be submitted to the solubility test before a 

 definite decision is made. 



G. SECRETORY FUNCTIONS OF 

 ACIDOPHIL CELL TYPES 



In view of the evidence presented earlier, 

 which indicates that acidophil cells secrete 

 somatotrophin and prolactin, it can be ex- 

 ])ected that in species in which two types 

 of acidophil can be distinguished, one type 

 will secrete somatotrophin, the other pro- 

 lactin. The reactivities of the cell types in 

 mammals, in which two types are distin- 

 guishable, show that this is indeed the case 

 and the point is discussed at some length in 

 the section on acidophil cells and somato- 

 trophin secretion which follows. 



In general one of the two specific cell 

 types is reactive in relation to the repro- 

 ductive cycle and shows marked fluctua- 

 tions in activity, which can be correlated 

 with the secretion of prolactin at times when 

 its luteotrophic, mammotrophic, or lacto- 

 genic action is apparent. The second type 

 is relatively stable in relation to the repro- 

 ductive cycle, and is assumed to secrete so- 

 matotrophin. Evidence in support of this as- 

 sumption is available in some species. 



Manimals in wliich the cai-iniiiophil cells 



