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Peripherally derived steroids affect steroid production in the brain via the blood–brain barrier. However, steroid concentrations are lower in the cerebrospinal fluid than those in the blood, indicating restricted influx of steroids because of their metabolization by choroid plexus (CP) epithelial cells. Here, we analyzed the gene expression of steroidogenic enzymes [cholesterol side-chain cleavage enzyme (P450scc), 17α-hydroxylase/C17-C20 lyase (P450c17), 3β-hydroxysteroid dehydrogenase (3β -HSD), 17β-hydroxysteroid dehydrogenase type 1 (17β -HSD1), aromatase (Cyp19a1), and 5α-reductase type 1 (5α -R1)]. These genes were expressed to a lesser extent in the CP than in the testis and to a similar extent in the cerebral cortex. However, P450scc levels were higher in the CP than in the cerebral cortex, whereas Cyp19a1 levels showed the opposite trend. We also evaluated the effects of orchiectomy and testosterone on the expression of these genes. P450c17 and 5α -R1 levels were unaffected by orchiectomy, whereas P450scc and 3β -HSD levels were increased and decreased, respectively. Cyp19a1 expression increased upon testosterone treatment, whereas that of 17β -HSD decreased upon orchiectomy or administration of testosterone. Immunohistochemistry analysis revealed that 17β -HSD was expressed in the cytoplasm of CP epithelial cells. These results indicate that CP epithelial cells synthesize and convert the certain types of steroids to contribute to the homeostasis of steroids in the brain.

The rat placenta is the primary source of androgens during the second half of pregnancy. Androgens are converted to estrogens in the ovaries and contribute to the maintenance of normal pregnancy. We immunocytochemically characterized the cellular and subcellular localization of cytochrome P450 of 17α-hydroxylase/C 17,20-lyase (P450c17), an enzyme responsible for androgen synthesis, in the rat placenta. We also observed the fine structure of the placenta by electron microscopy. The rat placenta had a different structure from the primate, and contained four zones :labyrinth, basal zone, decidua basalis, and metrial gland. The labyrinth had three trophoblastic layers and fetal endothelium, and P450c17 immunoreactivity was homogeneously localized in the three trophoblastic layers but not in the fetal endothelium. In the basal zone, various types of trophoblasts were observed, and the immunoreaction was localized in small basophilic cells and giant cells. The intensity of staining was heterogeneous among these cells. The decidua basalis showed no immunostaining. Subcellular localization of the enzyme was in the cytoplasm, but not in the nucleus or mitochondria. The present study demonstrated a steroidogenic potency in both the labyrinth and the basal zone, although it was shown only in the basal zone in previous studies.

A complete human skeleton was excavated from a burial mound built in the 6 th Century(Kofun period of Japan) at the top of Kanzo-yama hill of Itano-cho, Tokushima. Most of the cranio-facial bones, neck and upper thoracic bones appeared reddishly painted with mercuric cosmetics(mercuric sulfide). Bones were mostly laid ventral-up in the anatomical arrangement ; the cranium was dolico-cephalic(73.0 in cranial index), the midface low(54.7 in Kollmann index), and the nose middle(47.1 in nasal index). This is one of the most well-preserved excavations of human remains of the Kofun period of Toku- shima, an adult male estimated to be 162 cm in height.

A single hole penetrating tangentially through the middle of the dental root was found in a right central incisor of the mandible. The tooth was excavated from the bottom layer of the late Johmon and early Yayoi periods under the shell mound of Mitani ruin, Tokushima city. The hole is roundly polished to make a cone-like shape on both the mesial and distal sides without crack. There is neither pathological injury nor trace of living response on microscopy and X-ray test. It is strongly suggested that the hole was simply made on the tooth after extraction from the human mandible.