[Immunohistochemical studies of the localization of prolactin in human term decidua]

Human amniotic fluid possesses a considerably higher concentration of PRL. And it is generally accepted that decidual cells are the source of amniotic PRL and, decidual PRL transfers into amniotic fluid across the fetal membranes. Because few studies on the fine morphological structure of decidual tissue have been reported, with the aid of electron microscopy, we noted the number of secretory granules in the partial decidual cells which were obtained at spontaneous term vaginal delivery. 1 Using immunohistochemical procedures and the PAP complex method, immunized anti-PRL revealed PRL reactivity on the numerous granules or globules. 2 Incubation for acid phosphatase (AcP-ase) activity was done after the tissues were fixed. The medium used was Gomori lead medium, with glycerophosphate as substrate. Lysosomes are present in decidual cells. In lysosomes, numerous residual bodies with reaction product are evident as electro-opaque black bodies. 3 In staining of tissues for the study of lipid granules, Sudan III solution (Sudan Schwarz B dissolved in 70% alcohol) was used. Decidual cells contain fewer and bigger cytosolic lipid spheres.