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論文 |
論文
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Nakata, Hiroki ; Wakayama, Tomohiko ; Takai, Yoshimi ; Iseki, Shoichi
概要:
The aim of this study was to establish a quantitative standard for the cellular composition in seminiferous tubules at e
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ach stage of spermatogenesis in the mouse testis, and thereby evaluate abnormalities in the infertile mouse testis. We applied a combination of lectin histochemistry for acrosomes and immunohistochemistry for various specific cell markers, both of which were visualized with fluorescence, on paraffin sections of the testis. We first examined seminiferous tubules from normal mice and counted the number of each cell type at each stage of spermatogenesis. We then examined seminiferous tubules from genetically modified mice deficient (-/-) for one of the cell adhesion molecules, nectin-2 or nectin-3, and compared the number of each cell type at each stage of spermatogenesis with the corresponding value in normal mice. In both nectin-2-/- and nectin-3-/- mice, which are infertile despite the apparently normal morphology of the seminiferous epithelia, we measured a progressive loss in the later-step spermatids, with significantly lower numbers of step 11–16 spermatids in nectin-3-/- mice and step 15–16 spermatids in nectin-2-/- mice as compared with that in normal control mice. The present study demonstrated that a quantitative analysis of cellular compositions at different stages in seminiferous tubules was useful for evaluating abnormalities in spermatogenesis.
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論文
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井関, 尚一 ; Iseki, Shoichi
概要:
血管内皮増殖因子(VEGF)は、内皮細胞の受容体に働いて血管増生および血管透過性亢進をおこす分泌蛋白である。ラットVEGFの合成ペプチドへの抗体(IBL社)を用いた光顕および電顕的免疫組織化学により成熟ラットの全身器官を検索したところ、一部
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の内分泌細胞に強い免疫反応が得られた。隣接切片の抗ホルモン免疫染色との比較により、これらは下垂体のTSH細胞の一部、甲状腺の傍瀘胞細胞、膵臓のB細胞、および副腎髄質のN細胞であると判明した。免疫反応は合成ペプチドによる吸収試験で消失したので、VEGFに特異的であることが示された。電顕的には免疫反応はすべての陽性細胞で内分泌顆粒に局在した。従来VEGFの遺伝子発現は肝臓、腎臓などの血管豊富な器官で報告されているが、本研究は一部の内分泌細胞がVEGFを分泌することにより周囲の微小血管の透過性を制御する可能性を示唆した(論文1).さらに同じ抗体による免疫組織化学において、ラットの喉頭から気管上部にかけての上皮、小腸の粘膜固有層、および大腸、特に盲腸の上皮にVEGF免疫陽性細胞が散在していた。電顕的には陽性細胞は肥満細胞の特徴を持ち、粘膜型肥満細胞(globule leukocyteとも呼ばれる)と同定された。免疫反応は細胞質顆粒に局在した.隣接切片の抗ヒスタミン免疫染色と比較すると、VEGF陽性細胞のヒスタミン免疫活性は非常に弱かった.一方,気道の粘膜固有層や消化管の粘膜下組織に存在するヒスタミン強陽性の結合組織型肥満細胞ではVEGF免疫活性は非常に弱かった。本研究は気道や消化管の粘膜型肥満細胞がVEGFを分泌することにより周囲の微小血管の透過性を制御する可能性を示唆した。またVEGFが粘膜型肥満細胞を結合組織型細胞から区別する特異的マーカーになり得ることがわかった(論文2).<br />Vascular endothelial growth factor (VIEGE) is a potent angiogenic mitogen and also increases vascular permeability. Immunohistochemical localization of VEGF in the entire body of healthy adult rats was investigated at light and electron microscopic levels using a specific antibody. Intense to moderate immunoreactivities for VEGF were detected in certain endocrine cell types, namely, the parafollicular cell of thyroid gland, B cell of endocrine pancreas, N cell of adrenal medulla and a minority of the TSH cell of anterior pituitary gland. At the ultrastructural level, VEGF immunoreactivity was localized exclusively in the secretory granules of all immunopositive endocrine ells. These results provided immunohistochemical evidence for the occurrence of VIEGF in subsets of endocrine cells of normal adult rats, suggesting that these secretory cells regulate local vascular permeability through a paracrine action of VEGF (Reference 1).The results also showed solitary cells with strong VEGF im munoreactivity scattered in the epithelium of the respiratory tract as well as in the lamina propria and epithelium of the small and large intestines. By ultrastructural features of their large cytoplasmic granules, these VEGF-positive cells were identified as globule leukocytes (GL), also called mucosal mast cells (MMC). The immunoreactivity was localized exclusively in the cytoplasmic granules of GIIMMC.When examined in serial sections, GL/MMC in the respiratory and digestive tracts showed only weak reactivity to anti-histamine antibody. In contrast, connective tissue mast cells (CTMC), which were located in the submucosa of digestive tract and in the connective tissue of respitratory tract and a variety of other organs, were intensely immunopositive for histamine, whereas they showed no reactivity for VBGF.The specific appearance of VEGF immunoreactivity in GL/MMC suggested that this cell type is involved in the paracrine regulation of the permeability of nearl5y microvessels, and that VEGE can be used as a histochemical marker to distinguish GL/MMC from CTMC(Reference2).<br />研究課題/領域番号:09670006, 研究期間(年度):1997-1998<br />研究機関: 金沢大学医学部<br />出典：「内分泌系における血管内皮増殖因子(VEGF)の発現と局在」研究成果報告書 課題番号09670006 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）) 本文データは著者版報告書より作成
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