Immunohistochemical demonstration of prostaglandins in various tissues of the rat.

To demonstrate the tissue localization of prostaglandin (PG) E2, PGF2 alpha and 6-keto-PGF1 alpha (a stable metabolite of PGI2) various tissues, including decalcified periodontal tissue of 7-week-old male Wistar strain rats, were immunohistochemically examined using a streptavidin-biotin complex method. Besides tissue macrophages and endothelial cells in various tissues, hepatocytes, renal tubular cells, and parietal and chief cells in the gastric mucosa showed a positive reaction for the various PGs examined. PGs were demonstrated in the cytoplasm or in association with the cell membrane. We generally observed no difference between the localization patterns of PGE2-, PGF2 alpha-, and 6-keto-PGF1 alpha-positive cells in these tissues. However, in the periodontal ligament and alveolar bone, 6-keto-PGF1 alpha was localized in the cytoplasm of osteocytes, osteoblasts, cementocytes, and cementoblasts, while no reaction for PGE2 or PGF2 alpha was revealed in these cells. We demonstrated the immunohistochemical localization of PGs in various rat tissues including decalcified periodontal tissue and discuss the important roles of PGs in the modulation of their normal functions in these tissues.