182 



HYPOPHYSIS AND GOXADOTROPHIC HORMONES 



smaller animals causes a loss of the gran- 

 ules from basophil cells. Such hypophyses 

 are best fixed in situ. 



Basophil granules show a high capacity, 

 but only a weak binding power, for basic 

 dyes (Peterson and Weiss, 1955) . This baso- 

 philia does not serve for the characteriza- 

 tion of basophil granules because of the 

 prevalence of cytoplasmic basophilia and 

 the staining of acidoi)hil granules by basic 

 dyes. 



There has in the past been some confusion 

 between the basophilia of basophil granules 

 and that of ribonucleic acid. Dempsey and 

 Wislocki (1945) pointed out that the stain- 

 ing of basophils with aniline blue was not 

 concerned with cytoplasmic ribonucleic 

 acid, and suggested that the aniline blue 

 stained an acidophil substance which repre- 

 sented the true secretory granules of the 

 cells. The nature of the specific granules in 

 basophil cells was clarified by the researches 

 of Herlant (1942), who observed a violet 

 metachromatic staining of the basophil 

 granules in the human pituitary by neutral 

 solutions of toluidine blue. This metachro- 

 masia is observed only in undehydrated sec- 

 tions and demonstrates a specific type of 

 basophilia quite distinct from that due to 

 cytoplasmic ribonucleic acid. This type of 

 basophilia, which is common to many sites 

 containing polysaccharide material, was 

 considered by Herlant to indicate that the 

 specific granules of the basophil cells were 

 composed of glycoprotein. After a short 

 treatment with alcohol to cytolyze the cells, 

 the glycoprotein material was found to be 

 extractable by water, and the resultant ex- 

 tract was rich in FSH. Herlant demon- 

 strated the glycoprotein nature of the baso- 

 phil granules by the Bauer method for 

 polysaccharide, and the observations were 

 subsequently confirmed by the more satis- 

 factory McManus (1946) method for gly- 

 coprotein (Herlant, 1949). Other observa- 

 tions confirming the glycoprotein nature of 

 basophil gramdes have been reported by 

 Catchpole (1947, 1949), Pearse (1948), and 

 Purves and Gricsbach (1951a I. 



The Herlant metachromasia is observed 

 ill the basophil granules and indeed in all 

 P.\S stainable structures in rat, dog, and 

 litiinan hypophyses. This metachromasia 

 docs not serve to characterize basoi)liil gran- 



ules, inasmuch as the carminophil cells of 

 the dog and of the wallaby are also meta- 

 chromatically stained by toluidine blue. 



Basophil granules vary considerably in 

 size in different species. In the rat they are 

 seen in electron micrographs as spherical 

 bodies of a maximal size of 150 mix. The in- 

 dividual granules are not seen by the light 

 microscope, and the flocculent "granules" 

 seen in stained sections are the result of the 

 uneven distribution of the granules and 

 their aggregation during fixation and de- 

 hydration. In the human hypophysis the 

 basophil granules are much larger, and are 

 singly visible in lightly granulated cells in 

 stained sections. They vary greatly in size 

 and the largest among them are as large as, 

 or larger than, acidophil granules. 



In fresh tissue the basophil granules do 

 not show the high refractility of the solid 

 acidophil granules, and are therefore pre- 

 sumed to be vesicular, consisting of a mem- 

 brane enclosing a solution of glycoprotein. 



The staining procedures most generally 

 used in the study of the cytology of the 

 adenohyphophysis are various trichrome 

 procedures using mixtures of acid dyes. As 

 has been said before, by these methods baso- 

 phil granules may be stained orange, red, 

 purple, or blue. By such methods it is, of 

 course, not in general possible to distin- 

 guish acidophil granules from basophil gran- 

 ules. This was not realized until recently 

 because of a premature assumption that 

 only two types of chromoj^hil cells are pres- 

 ent in the pars anterior of mammals, and 

 because of a widespread erroneous belief 

 that all blue dyes are basic dyes. In the 

 literature, the term "basophilic" is con- 

 stantly applied to structures stained blue 

 by aniline blue in variations of the tri- 

 chrome staining procedures and is, there- 

 fore, used as a synonym for blue rather than 

 as an indication of staining affinity. 



It may be stated here, as regards tlie mul- 

 tiplicity of basophil cell tyi)es included in 

 the basophil cell class, that the pars inter- 

 media cells are basophils, and that there 

 are in addition three specific types of baso- 

 phil cells distinguishable in the pars anterior 

 of certain favorable mammalian species. 

 The immediately succeeding sections are 

 concerned with the basophil granules and 

 the basophil cell types of the pars anterior. 



