• Applied Microscopy
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• v.29 no.4
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• pp.511-522
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• 1999

The Leydig cell found within the interstitium of the testis is important in the spermatogenesis. The differentiation of Leydig cell, even though relatively well known in animals, is not fully elucidated yet in human. In the present study, human fetal testes ($14\sim27$ weeks) obtained from artificially induced abortions legally without gross malformations were studied using light and transmission electron microscopy to make clear the differentiation process of Leydig cells in humans. Leydig cells could be classified as 4 types: fusiform, light, dark, and degenerating cells. The most immature cell was the fusiform cells found frequently at 14 weeks, which seemed to differentiate successively into light and dark cells. Light cells were most frequently found at 17 weeks and dark cells at 24 weeks. Light cells were found to have mitochondria and smooth endoplasmic reticuli (sER) most prominently than any other cell types. The lumen of sER became to be expanded with age. Some electron-dense inclusions were observed in the mitochondrial matrix of the dark cells. Lipid droplets found more in light cells than dark cells were most prominent at 16 weeks and gradually decreased after 20 weeks. Glycogen particles were rich in dark cells. Degenerating cells were most frequently found at 27 weeks. From the results, it is suggested that Leydig cells in human fetal testes undergo similar differentiation process af in animals.

• Development and Reproduction
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• v.14 no.4
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• pp.297-306
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• 2010

Tributyltin (TBT), an endocrine disrupting chemical, has been reported to decrease testicular function by causing apoptosis in the testis, but this mechanism is not fully understood. Thus, in this study we examined whether TBT induces adipogenesis of the Leydig cells to find out the correlation between adipogenesis and apoptosis in the testis. Three week old SD male rats were orally administrated with sesame oil, 1 mg/kg of TBT, or 10 mg/kg of TBT daily for 1 week and weighed after administration. The testes obtained on day 8 were weighed and stained with BODIPY and TUNEL kit. Using total RNA extracted from the isolated Leydig cells, adipogenesis and apoptosis-related genes were analyzed by real-time PCR. The testicular weights of the rats treated with 10 mg/kg TBT were significantly decreased compared to those in the control rats treated with sesame oil. As a result of BODIPY staining, the number of Leydig cells stained with BODIPY was increased in the rats treated with 10 mg/kg TBT compared with the control rats. Similar to BODIPY staining results, the TUNEL assay showed that the apoptosis of Leydig cells was increased in TBT treated rats. The results of the gene expression analysis in the Leydig cells showed that the expression of adipogenesis-related genes (PPAR${\gamma}$, aP2, Perilipin, CD36) and apoptosis-related genes (TNFRSF1A, TNFSF10) was increased after TBT administration. The present study demonstrates that TBT induces the expression of adipogenesis-related and apoptosis-related genes in the Leydig cells leading to adipogenesis and apoptosis in the testes. These results suggest that the dysfunction of Leydig cells by TBT exposure may cause a loss in testicular function.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.193-205
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• 1994

In order to understand fine structural and histochemical changes in the cyst cell and he interstitial cell in the testis of the spottybelly greenling Hexagrammos agrammus associated with the reproductive cycle from January to December, 1992, there cells were studied by electron microscopy and light microscopy. The cyst cells in the mature testis show a weak affinity to haematoxylin. while they become larger in size. At this time, these cells appear to be more functional than those on the growing stage because several mitochondria, endoplasmic reticulum, glycogen particles and a few lipid droplets appear in the cytoplasm of the cyst cell. It appears, therefore, that the cyst cell of this species has vital functions for nutrition, secretion and steroidogenesis. Well-developed interstitial cells contain large rod-shape or spherical mitochondria with tubular cristae and the large quantities of smooth endoplasmic recticulum and electron-dense materials in the vesicle at the mature and spawning stage. The interstitial cells of this species show characteristics of steroid interstitial cells having a vesicular nucleus, mitochondria with tubular cristae, and smooth endoplasmic reticulum. However, these interstitial cells of teleost give negative histochemical reactions for Sudan black B.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.311-318
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• 2006

Ultrastructure of germ cells, the cyst epithelial cells and interstitial cells during spermatogenesis of the stone flounder, Kareius bicoloratus (Pleuronectidae) sampled on the west coast of Korea were investigated by electron microscopic observations. In the primary spermatocyte, the synaptonemal complexes appear in the zygotene stage of the prophase during maturation division. In the growing testis, especially, the interstitial cells (Leydig cells) appear near the primary, secondary spermatocytes and spermatids. Well-developed interstitial cells (steroid hormone secreting cells) which are located in the interlobular space in growing testis have three morphological characteristics of a vesicular nucleus, mitochondria with tubular cristae and smooth endoplasmic reticulum. During spermatogenesis, the primary and secondary spermatocytes attach to the cyst epithelial cell (Sertoli cell) having an elongated ovoid or triangular nucleus and several mitochondria in the cytoplasm. In the growing testis, lipid droplets, the mitochondrial rosettes and glycogen particles appear in the cytoplasm of the cyst epithelial cells near the secondary spermatocytes and spermatids. Particularly, the mitochondria, endoplasmic reticulum, little lipid droplets and the large amount of glycogen particles are present in the cytoplasm of the cyst epithelial cell in the late growing testis. In the late stage of spermiogenesis, the proximal centriole is joined to the nuclear envelope, the distal centriole forms the basal body of the flagellum and gives rise to the axial filament of the flagellum. No acrosome of the sperm is formed as seen in other teleost fish. The head of the spermatozoon is approximately $3{\mu}m$ in length and its tail is about $30{\mu}m$ in length. The axoneme of the tail flagellum of the spermatozoon consists of nine outer doublet microtubules at the periphery and two centrial singlet microtubules at the center. The spermatozoon of this species has two axonemal lateral fins. Especially, the cyst epithelial cells which located near groups of gametes in the various stages, show three functions: nutrition, phagocytosis and steroidogenesis. Especially, the nuclei of cyst epithelial cells in the recovery stage of the testicular developmental stages appear to be irregular in shape after spermiation. Of three functions of the cyst epithelial cell, several characteristics of phagocytosis are showed in the cytoplasm of the cyst epithelial cells in the recovery stage of the testicular developmental stages. At this stage, therefore, it is assumed that the cyst epithelial cells are involved in degeneration and resorption of undischarged germ cells after spermiation.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.181-188
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• 2006

Changes in the fine structure of testicular Leydig cell from hatching to adulthood were studied in Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The objective of this study were to elucidate Leydig cell ultrastructure during testicular development. Testes of chickens were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ sections stained with methylene blue-azure II, qualitative and quantitative(stereological) morphological studies were performed. The ultrastructural changes of the Leydig cell were investigated by ultrathin section with the transmission electron microscope. The stages of the Leydig cell development described focus on mitochondria, endoplasmic reticulum, and lipid droplets which are involved in androgens as fullows. 1) Approaching puberty. The closely packed Leydig cells and sparse intercellular space. The nucleus occupied a large portion of the Leydig cell volume. The population of Leydig cells contained two types of cells that differed in the appearance of their nuclei which were either highly electron-opaque or relatively electron-lucid. The cytoplasm was characterized by large amounts of lipid droplets, relatively few spherical mitochondria, and sparse smooth endoplasmic reticulum. 2) Puberty to adult. The Leydig cells which display features compatible with significant androgen synthesis: large volume of cytoplasm containing extended smooth endoplasmic reticulum, abundant mitochondria, and reduction of lipid droplets.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.469-470
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• 2004

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.417-423
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• 1997

돼지 생식기 호흡기 증후군 바이러스의 nucleocapsid와 반응을 하는 SDOW17 단크론항체를 이용하여 중성 포르말린에 고정시킨 자연감염된 포유자돈의 폐장에서 면역조직화학법을 이용하여 돼지 생식기 호흡기 증후군 바이러스 항원을 확인하였다. 서울대학교 수의과대학 병리학교실에 의뢰된 포유자돈들 중에서 병리조직학적으로 폐장에서 간질성 폐렴이 관찰된 포유자돈 7두를 임의로 선택하여 본 실험을 실시하였다. 간질성 폐렴의 병변으로 많은 수의 대식세포 침윤을 동반한 폐포벽 두께의 증가와 제II형 폐포세포의 비후가 관찰되었다. 검사한 7두 포유자돈중에서 6두에서 돼지 생식기 호흡기 증후군 바이러스에 대한 항체를 enzyme-linked immunosorbent assay에 의해 확인하였다. SDOW17 단크론항체를 이용한 면역조직화학염색과 간질성 폐렴의 대식세포에서 돼지 생식기 호흡기 증후군 바이러스의 항원을 검출하였고, 항원은 (주로)대식세포의 세포질에서만 진한 갈색의 양성반응이 관찰되었다. 이상 검사결과 돼지 생식기 호흡기 증후군 바이러스는 폐장의 간질과 폐포강에 분포되어 있는 대식세포에서 주로 증식하는 것으로 판명되었다. 본 실험에서 사용한 면역조직화학법은 돼지 생식기 호흡기 증후군 바이러스 감염여부를 바이러스 분리 또는 혈청검사 없이 진단하는데 사용할 수 있는 유용한 진단방법으로 판명되었다.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.515-524
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• 1997

헤민과 메나디온 제한에 의한 Porphyromonas gingivalis(P. gingivalis) W50의 병독력의 변화를 검색하고자, 실험관내 병독력을 NIH 3T3 세포의 세포활성 변화로 관찰하였고, 생체내 병독력은 배양상청액을 ICR mouse 피하조직에 주사한 후의 염증반응을 관찰하였다. 헤민 존재 하에 배양한 P. gingivalis W50 배양상청액에 의한 mouse 3T3 세포의 세포활성은 헤민과 메나디온 없이 배양한 세포의 활성보다 낮았다. 헤민과 메나디온을 첨가하지 않고 배양한 세균의 생체내 병독력은 중등도의 염증세포 침윤과 울혈에 의한 출혈, 미약한 세포간질의 부종과 근육 파괴를 보였다. 메나디온 존재 하에서 배양한 세균은 미약한 염증세포의 침윤, 울혈에 의한 출혈 및 근육의 파괴가 관찰되었다. 헤민 존재하에서 중등도의 울혈에 의한 출혈, 미약한 세포간질의 부종, 염증세포의 침윤 및 근육파괴가 관찰되었다. 헤민과 메나디온 존재 하에서 배양한 세균은 심한 염증세포의 침윤과 중등도의 세포간질의 부종 및 울혈에 의한 출혈을 보였다. 이상의 연구 결과 P. gingivalis W50 배양 상층액의 병독력은 헤민에 의하여 영향을 받는 것으로 생각된다.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.505-512
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• 2005

Excitotoxicity and epileptogenesis have often been associated with glutamate receptor activation. Accumulating evidences indicates that topiramate (TPM), an antiepileptic drug with multiple mechanisms of action has neuroprotective activity. We explored the neuroprotective effect of TPM on the status epilepticus (SE)-induced hippocampal neuronal death. After development of SE by kainite injection (15 mg/Kg), rats were treated with TPM (10mg/kg) for 1 week. The neuronal death was detected by Apop tag in situ detection kit, and the expression levels of glutamate receptors were semi-quantitatively analyzed by immunoblot. Kainate-induced SE caused a significant neuronal death and cell loss in CAI and CA3 regions of hippocampus at 1 week. However, treatment of TPM for 1 week after SE markedly reduced hippocampal neuronal death. The expression of N-methyl-D-aspartate (NMDA) receptor subunit 1, was increased by SE, but was not affected by 1 week treatment of TPM. The expressions of NMDA receptor subunit 2a and 2b were not changed by either SE or TPM. As for ${\alpha}-amino-3-hydroxy-5-methyl-4-isoxazole-propionate$ (AMPA) glutamate receptors (GluR), kainate-induced SE markedly up-regulated GluR1 expression but down-regulated GluR2 expression, leading to increased formation of $Ca^{2+}$ permeable GluR2- lacking AMPA receptors. TPM administration for 1 week attenuated SE-induced expression of both the up-regulation of GluR1 and down-regulation of GluR2, reversing the ratio of GluR1/GluR2 to the control value. In conclusion, TPM protects neuronal cell death against glutamate induced excitotoxicity in kainate-induced SE model, supporting the potential of TPM as a neuroprotective agent.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.125-133
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• 2005

Morphometric changes in testicular Sertoli and Leydig cells from hatching to adulthood were studied using Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The objective of this study was to understand the developmental phase of the Sertoli and Leydig cells with age. Testis of chickens was fixed by whole body perfusion using a fixative containing $2.5\%$ glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 Um sections stained with methylene blue-azure II, qualitative and quantitative (stereological) morphological studies were performed. The average volume of a testis of 1 week old Korean native chickens was determined as $0.148\;cm^3$ and the parameter increased linearly from 1 week to 21 weeks days $(28.86\;cm^3)$, and did not change from 21 weeks to 64 weeks. The volume density of the seminiferous tubules increased with age from $32.6\%$ at week 1 to $92.89\%$ at week 64. The volume density of the interstitium represents $67.4\%$ of the testicular parenchyma at week 1. This proportion progressively diminished during development to reach a value of $7.11\%$ at week 64. The volume density of the Leydig cells decreased almost linearly from 1 week $(4.9\%)$ to 14 weeks $(1.7\%)$ and remained unchanged thereafter. In contrast, the Sertoli cells occupied a volume density of $3.4\%$ at week 1, increased progressively up to 18 weeks of age $(10.79\%)$ and remained unchanged thereafter. The absolute volume of the Leydig and Sertoli cells per testis increased significantly from week 1 to week 21 but did not change significantly from week 24 to week 64. The number of Leydig cells per testis increased almost linearly from 1 week to 21 weeks, remained high and unchanged with advancing age. The number of Sertoli cells per testis increased gradually with age from 1 week to 14 weeks and remained unchanged thereafter.