English
TitleCELL KINETICS OF THE ADRENAL GLAND, THE GONADS AND THE THYMUS IN PERINATAL RAT A Whole Body Autoradiogram by The Use of Dry Mount Autoradiography
SubtitleOriginal articles
AuthorsToshiaki NAKAI*
Authors(kana)
Organization*Department of Clinical Pathology and Metabolism, DOKKYO University School of Medicine
JournalThe Japanese Journal of nuclear medicine
Volume14
Number6
Page857-862
Year/Month1977/12
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Synopsis] : Distribution of 3H-thymidine in the perinatal rat, with special reference to cell dynamics of the gonads, the thymus and the adrenal cortex, was investigated with the use of our modified dry mounting autoradiographic techniques, which enabled us to observe the distribution of radioactivity in a whole body section of a rat. The thymus displayed intense labeling in a fetal rat in which the growth rate was rapid. It is, therefore, reasonable that there are considerable number of thymic cells engaged in cell division. The outerzone of the adrenal cortex and the testis displayed a moderate degree of synthetic activities. There were few labelled cells in the innerzone of the adrenal cortex. The observations seem to indicate the inward displacement of cells (cells derived from the outerzone move into the innerzone) , supporting the centripetal cell displacement theory. The ovary showed a lower degree of synthetic activity than the testis. The difference of labelling index between the ovary and the testis may be partly due to the difference of hormonal activities, - the testis begins to function before birth, while the ovary is hormonally quiescent in fetal life. Since 3H-thymidine has been reported to be incorporated specifically into newly synthesized DNA prior to the cell division, a combination of the use of 3H-labeled thymidine and the autoradiographic techniques has been extensively attempted to investigate the DNA-synthesis in cells and tissues for more than two decades. 3H-thymidine is probably the most widely-used tracer in modern cell biology, stimulating numerous studies regarding the kinetics of cellular proliferation in a variety of tissues. Most of the autoradiographic studies hitherto reported have been carried out using early postnatal or young animals, but little observation has been made on cell growth dynamics in perinatal life. Development of the whole-body autoradiography has enabled us to observe the distribution of radioactivity in a whole-body section of a rat. The present study was undertaken to investigate cell growth dynamics of various tissues, particularly those of the gonads, the adrenal gland and the thymus in the perinatal rat, with the aid of our modified dry-mounting autoradiographic techniques.
PracticeClinical medicine
Keywords
Japanese
Title出生前後ラットにおける副腎皮質・性腺・胸腺のCell Kineticsについて - ドライマウントオートラジオグラフィーを用いての全身オートラジオグラム -
Subtitle原著
Authors中井利昭
Authors(kana)
Organization独協医科大学臨床病理・代謝科
Journal核医学
Volume14
Number6
Page857-862
Year/Month1977/12
Article原著
Publisher日本核医学会
Abstract副腎皮質, 性腺等の内分沁腺のcell kineticsについては, 成熟または幼若期の報告はいくつかみられるが, perinatal期, とくに胎生期についての報告は今までみられない. 今回われわれの改良, 考案したdry mount autoradiographyを用いてのwhole body autoradiogramにより, perinatal期のラットの内分泌腺のcell kineticsを検索し, 機能的な発育との関連についていささかの知見を得たのでここに報告する. 3H-thymidineを22日齢胎仔および生後1日, 3日齢の新生仔ラットに注射し, 30分後その体内分布を凍結乾燥切片によるwhole body autoradiogramにより検討した. 各臓器の3H-thymidineのlabeling状態を比べてみると, 胸腺は最も細胞分裂が盛んであった. 生後の胸腺については生直後labeling indexは高いが胸腺の退化がおこる60日齢頃に一致してlabeling indexの減少がおこるという報告があるが, われわれの結果も生前においてはlabeling indexが高く, その旺盛な発育を示唆するものである. 副腎皮質の外層は中等度の分裂像を示したが, 副腎皮質の内層にはほとんど分裂像が認められなかった. このことは生後ラットの副腎皮質についてのinward displacement theory - すなわち皮質外層細胞が内層へと移動する - をperinatal期においてもsupportする所見である. 性腺については精巣の方が卵巣に比べより盛んな分裂像を示した. 組織学的所見によると, 胎生期精巣は分化が進んでseminiferous tubulesもみられるが, 卵巣は未だ未分化でfollicleもみられないというが, 精巣と卵巣のcell kineticsの違いはこの分化の違いに一因していよう. 以上われわれの改良, 考案したdry mount法を用い, 胎仔ラットに3H-thymidineを投与したautoradiogramを作成した結果, 各臓器の細胞の分裂像のみならず, その臓器の機能との関連をも明らかにした.
Practice臨床医学：一般
Keywords

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