928 



SPERM, OVA, AND PREGNANCY 



later. This enzymatic activity is high in the 

 syncytial trophoblast of the cat, rodents 

 (Figs. 15.71 and 15.73), shrews, and bats. 

 Alkaline phosphatase occurs in the visceral 

 endoderm of the splanchnopleuric yolk sac 

 of rodents (Fig. 15.70) (Hard, 1946; Wis- 

 locki, Deane and Dempsey, 1946; Pritch- 

 ard, 1947; Padykula, 1958a), shrews (Wis- 

 locki and Wimsatt, 1947), and bats 

 (Wimsatt, 1949). Thus, this enzyme is lo- 

 cated at two major placental aljsorptive 

 surfaces. 



In the pig's placenta, alkaline phospha- 

 tase activity is high in the columnar epi- 

 thelial cells of the chorionic fossae (Fig. 



15.67) and in the stroma and blood vessel 

 walls of the maternal endometrium (Fig. 



15.68) (Wislocki and Dempsey, 1946b; 

 Dempsey and Wislocki, 1947) . However, it 

 is completely absent from the chorionic 

 areolae and extremely low in the epithelium 

 of the chorionic rugae. In the coiv and sheep, 

 binucleate trophoblastic giant cells are ricli 

 in alkaline phosphatase (Wimsatt, 1951). 

 In the Virginia deer at midgestation, this 

 enzyme was found in the binucleate giant 

 cells, stroma and walls of the blood vessels 

 of the maternal septa, epithelium clothing 

 these septa, and at the surface of the tro- 

 phoblast covering the chorionic \\\\\. In the 



cat, alkaline phosphatase occurs also in ma- 

 terial surrounding the capillaries and de- 

 cidual giant cells (Fig. 15.60). In the para- 

 placental "brown" border of the cat, there 

 is abundant alkaline phosphatase activity 

 in the uterine glands and surface epithe- 

 lium, in the uterine secretion, and in the 

 outer parts of the columnar epithelial cells 

 of the membranous chorion (Fig. 15.63). 



Acid phosphatase occurs in the human 

 syncytium and also in the labyrinthine tro- 

 phoblast of the i^at where it increases in 

 activity in the last week of gestation (Pady- 

 kula, 1958). In the rat placenta, this en- 

 zyme appears in the cytotrophoblast of the 

 spongy zone and in the giant cells on the 

 17th day and increases steadily until term. 

 In the cat, acid phosphatase occurs in the 

 trophoblast of the placental lamellae, in the 

 uterine glands, in the uterine surface epi- 

 thelium, and to some degree in the epithe- 

 lium of the membranous chorion (Wislocki, 

 1953). In the pig, acid phosphatase activity 

 is high in the uterine glands (Fig. 15.69), 

 in the uterine milk occurring in the lumens 

 of the chorionic areolae, and in the distal 

 ends of the epithelial cells lining the area- 

 lae (Wislocki and Dempsey, 1946b; Demp- 

 sey and Wislocki, 1947) . The activity of the 

 uterine surface epithelium is moderate. In 



Plate 15.XIV 



Fig. 15.59. Frozen section of the placental labyrinth of a cat, viewed under a polarizing 

 microscope, to illustrate the strong birefringence encountered in the cellular trophoblast of 

 the placental lamellae (fetal crown to rump length, 110 mm.). The birefringence is associated 

 with numerous sudanophilic lipid droplets which exhibit greenish fluorescence and give a 

 positive Ashbel-Seligman reaction for carbonyl groups. Compare with Figure 15.20 which 

 illustrates the carbonyl reaction. X 280. (Wislocki and Dempsey, 1946a.) 



Fig. 15.60. A placental lamella of a cat, illustrating the presence of alkaline phosphatase 

 in the interstitial matrix around the maternal blood vessels and decidual giant cells and ex- 

 tending into the syncytial trophoblast (embryo length, 13 mm.). Gomori's method, using 

 glycerophosphate as substrate at pH 9.4. X 800. (Wislocki and Dempsey. 1946a.) 



Fig. 15.61. Placental lamellae of a cat (fetal crown to rump length, 45 mm.), illustrating 

 the periodic acid-Schiff (PAS) reaction which is localized in the interstitial matrix surround- 

 ing the maternal blood vessels and decidual giant cells and intervening between them and the 

 trophoblast. Compare with the similar localization of alkaline phosphatase in Figure 15.60 

 and also with Figure 15.56. Zenker's acetic acid fixative. Treatment with saliva. X 260. 



Fig. 15.62. The paraplacental endometrium ("brown" border) of a pregnant cat (fetal 

 crown to rump length, 45 mm.), illustrating the intense PAS reaction in the secretion of the 

 uterine glands which is poured into the uterine lumen. A reaction is present also in the cyto- 

 plasm of the distal ends of the uterine epithelium. The paraplacental chorionic membrane 

 (opposite the uterine epithelium at the extreme upper border of the photograph) consists of 

 columnar cells the supranuclear cytoplasm of which contains PAS-stained droplets. Zenker's 

 acetic acid fixative. Treated with saliva. X 260. 



Fig. 15.63. The paraplacental "brown" border of a pregnant cat (fetal crown to ru.mp 

 length, 45 mm.), illustrating the intense alkaline phosphatase reaction in the endometrium 

 (right) and lesser reaction in the chorion (left). Gomori's method, using glycerophosphate 

 as substrate at pH 9.4. X 120. 



