HYPOPHYSEAL MORPHOLOGY 



175 



stained by the Baker acid hematein test for 

 phospholipid. In sections the same test pro- 

 duces a dark coloration of acidophil cells 

 which is attributable to, in the main, stain- 

 ing of the granules (Rennels, 1953). There 

 is some conflict of opinion as to whether 

 this staining indicates the presence of phos- 

 pholipid or is the result of some property 

 of the granule protein. Herlant (1952a) and 

 Elftman (1956) consider the reaction not to 

 indicate phospholipid, but the evidence on 

 which this conclusion is based is contradic- 

 tory to the observations of Racadot (1954) 

 and Ortman (1956) . The value of the hema- 

 tein staining as a specific stain for acidophil 

 granules is diminished by the positive stain- 

 ing of mitochondria and of phospholipid and 

 other materials in basophil cells. 



C. SULFHYDRYL AND DISULFmE CONTENT 



OF AcmopHiL c;ranules 



Ladman and Barrnett ( 1954) described 

 the staining of acidophil cells in the rat by 

 the Barrnett-Seligman technique which is 

 l)resumed to be specific for sulfhydryl and 

 disulfide groups. This staining in acidophil 

 cells is obtained only after fixation in Zen- 

 ker's fluid. After fixation in acid alcohol and 

 a number of other fixatives the cells do not 

 stain. This observation could be interpreted 

 to indicate the presence in acidophil gran- 

 ules of a sulfur-rich protein soluble in acid 

 alcohol and preserved only by fixation in 

 Zenker's fluid. Because of the possibility of 

 formation of mercury compounds by the ac- 

 tion of the fixative, and because such com- 

 pounds might also react with the reagent 

 used to demonstrate sulfhydryl groups, 

 these results should be interpreted with cau- 

 tion. An increased staining after Zenker 

 fixation, in comparison with acid alcohol 

 fixation, is common to many animal tissues 

 (Barrnett, 1953; Barrnett and Seligman, 

 1954). It has not been shown that treatment 

 with Zenker's fluid after previous fixation 

 in acid alcohol does not induce this type of 

 staining. Adams and Swettenham (1958) 

 showed that staining of the acidophil 

 granules in the human pars distalis by the 

 Barrnett-Seligman reaction was not due to 

 cystine, because it was not blocked by 

 oxidation of the sulfide linkages to sulfonic 

 acid groups by performic acid. It should 

 also be noted that the acidophil granules did 



not react positively to other histochemical 

 tests for cystine. 



D. HORMONE CONTENT OF ACIDOPHIL CELLS 



An indication of the probable nature of 

 the hormonal secretions of cells of the acido- 

 phil class is obtainable from the assay of 

 portions of the acidophil and basophil zones 

 of the pars anterior. Experiments of this 

 sort were first made by Smith and Smith 

 (1923a, 1)), who found that the central 

 basophil zone of the bovine pituitary stimu- 

 lated metamorphosis in hypophysectomized 

 tadpoles with accompanying stimulation of 

 the thyroid gland; the outer acidophil-rich 

 portions caused an unusual stimulation of 

 growth without causing either metamorpho- 

 sis or activation of the thyroid. These re- 

 sults indicate the probability that growth 

 hormone is present in high concentration in 

 parts of the gland which are rich in acido- 

 phil cells. Azimov and Altman (1938) and 

 Friedman and Hall ( 1941 ) found a differ- 

 ential concentration of prolactin in the pe- 

 ripheral acidophilic zones of the bovine 

 hypophysis. 



The problem of the distribution of the 

 corticotroi)hin in the predominantly acido- 

 jihilic and basophilic zones was apparently 

 decided by the consistent results obtained 

 by Smelser ( 1944) and Giroud and Martinet 

 ( 1948) , who found that the adrenal weight- 

 increasing action was predominantly situ- 

 ated in the basophil zone. Later discoveries 

 concerning the unreliability of the adrenal 

 weight increase as a measure of adreno- 

 corticotrophic activity made these results of 

 less significance than was formerly believed. 

 Some observations suggested that the adre- 

 nocorticotrophic hormone may, in fact, be 

 present in high concentration in the acido- 

 phil zone. Chiti and Zinolli (1952) found 

 that both the acidophilic and basophilic 

 zones of the pig hypophysis have an action 

 on the guinea pig adrenal cortex, and that 

 there is a difference in the response to the 

 two zones. The response to the basophilic 

 zone was more marked in the fasciculata of 

 the adrenal cortex, whereas the tissue of the 

 acidophilic zone caused an enlargement of 

 the reticularis. Desclaux, Soulairac and Cha- 

 neac (1953) using beef pituitaries found that 

 implants of the basophil zone placed in con- 

 tact with the adrenal of the rat did not mod- 



