934 



SPERM, OVA, AND PREGNANCY 



continued production of chorionic gonado- 

 trophin. 



The gonadotrophic hormones of both 

 pituitary and placenta are known to be gly- 

 coproteins (Bettelheim-Jevons, 1958). Pu- 

 rified gonadotrophins of pituitary and pla- 

 centa contain hexose and hexosamine. 

 Catchpole (1949 J reported that he found a 

 glycoprotein constituent of the basophil cells 

 of the hypophysis of the rat, demonstrable 

 by means of the PAS stain. On the basis of 

 the increase of this reaction after castration, 

 as well as from other physiologic correlates, 

 he concluded that a part of the material 

 represents the follicle-stimulating hormone. 

 Pearse (1949) likewise observed a positive 

 PAS reaction in the pituitary basophils 

 which he ascribed similarly to the gonado- 

 trophic hormone. Moreover, he described a 

 particular type of vesiculated chromophobe 

 which he suggested might represent a phase 

 in the secretory cycle of the basophils. 

 Purves and Griesbach (1951a, b) estab- 

 lished that there are two categories of gly- 

 coprotein-containing basophils in the rat pi- 

 tuitary, the gonadotrophs and thyrotrophs. 

 (See also discussion in chapter by Purves.) 

 These two groups of basophils can be dis- 

 tinguished on the basis of shape, geograph- 

 ical distribution, nature of granulation, and 

 responses to changes in hormonal environ- 

 ment. Pearse (1949) noticed PAS-positive 

 material in the form of granular masses, 

 globules, and vesicles in "the trophoblast 

 layer of the placenta and in the Langhans 

 cells of chorionepithelioma." Inasmuch as 

 the granular part of this material could be 

 removed bv diastase, it seemed to consist of 



glycogen. However, the globules and vesi- 

 cles which were saliva fast he regarded as 

 being probably of "mucoprotein nature" and 

 as representing chorionic gonadotrophin. 



Wislocki, Dempsey and Fawcett (1948) 

 mentioned briefly that after fixation in 

 Rossman's fluid and removal of glycogen 

 they were unable to demonstrate any reac- 

 tion in the cytotrophoblast by the PAS 

 method. However, on further trials with 

 other fixatives, including Zenker's acetic acid 

 mixture and Orth's fluid, delicate granules 

 were rendered visible (Wislocki, 1950) in 

 the cytoplasm of some fraction of the periph- 

 eral trophoblasts throughout gestation (Figs. 

 15.49 and 15.55). These fine, but often in- 

 distinct, particles are more like those de- 

 scribed in the pituitary basophils by Catch- 

 pole (1949) than the globules and vesicles 

 mentioned by Pearse (1949) which were not 

 seen in these preparations. Although the re- 

 actions observed in the peripheral cytotro- 

 phoblast may bear a relationship to the 

 presence of chorionic gonadotrophin, it 

 should not be overlooked that the syncytial 

 trophoblast also exhibits a delicately stip- 

 pled, variable reaction and that its outer 

 surface and brush border are quite strongly 

 stained (Figs. 15.29 and 15.54). Further- 

 more, it should be borne in mind that a 

 variety of carbohydrate-containing sub- 

 stances, including various mucopolysaccha- 

 rides, glocoproteins glycolipids, and gly- 

 coliproproteins react with the PAS reagents 

 and that such reactive substances are widely 

 distributed in cells and tissues. As a result 

 of this, the possible identification of cho- 

 rionic gonadotrophin by this single reaction 



Plate 15.XVI 



Fig. 15.70. The placenta of a guinea pig (fetal crown to rump length, 75 mm.), illustrating 

 the distribution of alkaline phosphatase. The reaction is extremely intense in the placental 

 cotyledons (fine-meshed s>'ncytium) and diminishes abruptly in the coarse, interlobular syn- 

 cytium. The villous portion of the yolk sac (at top of figure above the placenta) is also rich 

 in alkaline phosphatase. The subplacenta beneath the placental labyrinth is negative, but 

 the junctional and decidual zones are quite reactive. Gomori's method, using gh^cerophos- 

 phate as substrate at pH 9.4. X SVi. (Wislocki, Deane and Dempsey, 1946.) 



Fig. 15.71. The placental labyrinth of a mouse, on the 15th day of gestation illustrating 

 the intense alkaline phosphatase reaction in the trophoblastic syncytium. Gomori's method, 

 using glycerophosphate as substrate at pH 9.4. X 170. (Wislocki, Deane and Dempsey, 1946.) 



Fig. 15.72. The chorio-allantoic placenta and yolk sac of a rat on the 21st day of gestation, 

 illustrating the periodic acid-Schiff reaction of the epithelium of the villous portion of the 

 yolk sac and of Reichert's membrane. Orth's fixative. Treatment with saliva. X 175. (Wis- 

 locki and Padykula, 1953.) 



Fig. 15.73. A detail of the guinea pig's placenta shown in Figure 15.70, illustrating the in- 

 tense alkaline phosphatase reaction in the trophoblastic syncytium enclosing the maternal 

 vascular channels. X 830. (Wislocki, Deane and Dempsey, 1946.) 



