Figure 6

LHR immunoreactivity in chorionic villi and placental membranes. A) LHR+ mononucleated trophoblast (arrowheads) and villous vascular sinusoids (v) in normal term placentae. Note unstained syncytium (white asterisks) or sporadic LHR+ granules (black asterisk). B) Detail from (A) (turned 90°) shows cytotrophoblast cells merging with syncytium (full arrowheads vs. white arrowhead), followed by diminution of LHR immunoreactivity (red arrowhead). C) Villous sinusoids. D) Immature (developing) villus in normal placenta. E) Abnormal placenta (note enhanced dilatation of all sinusoids – compare with A). Panels (F–H) show staining for LHR (DAB-Ni substrate) in various placental types (see text) vs. control (I). J) Occasionally detected multilayered amniotic epithelium shows a transition from granular cytoplasmic (full arrowhead) to perinuclear (yellow arrowhead) and nuclear LHR immunoreactivity (red arrowhead). Note unstained surface cells (white arrowhead). K) Extravillous trophoblast cells (basal plate) with strong perinuclear staining (full arrowheads) variable LHR immunoreactivity in decidual cells (white arrowheads). L) Parallel section shows Thy-1+ decidual cells (white arrowhead) and unstained trophoblast cells (full arrowhead). M) Dual color immunohistochemistry: extravillous trophoblast expressing LHR (full arrowhead), decidual cells expressing both markers (white arrowhead) and decidual macrophages expressing CD68 only (red arrowhead). Hematoxylin counterstain except panels F–I and panel M (dual color immunohistochemistry). Bar in C, for B and C; bar in H, for F–I. For other panels see bar in A.