• Applied Microscopy
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• 제32권4호
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• pp.303-310
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• 2002

우리나라 동해안에 가장 많이 서식하는 조개류인 대복의 정소구조와 정자형성과정을 광학현미경과 투과전자현미경으로 조사한 결과는 다음과 같다. 대복의 정소는 소성결합조직으로 구성된 다수의 정자형성 소낭을 가진다. 동일한 정자형성 소낭 내에서는 여러 단계의 생식세포들이 관찰되었다. 정원세포들은 정자형성 소낭벽에 부착되어 있으며, 커다란 핵과 뚜렷한 인을 가진다. 정모세포에서는 연접사복합체와 골기체의 발달을 확인할 수 있었다. 정세포의 핵은 전자밀도가 높은 과립상의 염색질로 구성되며, 정자변태과정 동안에 핵의 응축 및 첨체와 편모의 형성을 관찰할 수 있었다. 정소 내에서 완숙 정자들은 다발을 형성하고 있으며, 두부, 중편, 미부로 구성되어 있었다. 두부의 길이는 약 $8.5{\mu}m$로, 첨체부와 핵 부위로 구분된다. 첨체는 길이 약 $1.1{\mu}m$의 총알형태였다. 두부와 첨체 사이에서는 미세섬유로 구성된 첨체기둥이 확인되었다. 중편에는 4개의 미토콘드리아를 가지며, 꼬리의 횡단면은 "9+2"의 구조를 나타냈다.

• Animal cells and systems
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• 제1권1호
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• pp.99-105
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• 1997

Using three species of Korean frogs (Rana dybowskii, R. rugosa and R. nigromaculata), the annual spermatogenic pattern, the seasonal changes in the steroidogenic competence, and responsiveness of testis to gonadotropins in terms of testosterone secretion in vitro were examined. The spermatogenic pattern of R. dybowskii was classified as a discontinuous type since spermatogenesis stops completely after spawning in late winter (February) until mid-summer (July). In contrast, the pattern of R. nigromaculata and R. rugosa was classified as a potent continuous type since sperm was always present in the seminiferous tubules all year round. In all three species, the levels of testicular testosterone and that of testosterone secreted by testis following in vitro culture were very low in late summer (August), but increased thereafter until winter (hibernation period). Interestingly, responsiveness of testis in vitro to gonadotropins in terms of testosterone secretion increased markedly in November (early hibernation period). Specifically, bullfrog LH was more effective than FSH in stimulating the secretion of testosterone by frog testis in vitro during hibernation period. This fact suggests that testosterone secretion by testis during hibernation is at least regulated by the pituitary gonadotropin rather than environmental factors. Taken together, the data presented here suggest that testicular cycles of three species of Korean frogs are closely linked to their females breeding cycles, and are eventually controlled by various environmental cues.

• 대한수의학회지
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• 제59권2호
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• pp.59-67
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• 2019

We investigated whether ${\beta}$-carotene (${\beta}-CA$) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of ${\beta}-CA$ or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at $43^{\circ}C$ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and $HIF-1{\alpha}$ mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, $NF-{\kappa}B$, and $TGF-{\beta}1$ mRNAs), and androgen biosynthesis (serological testosterone concentration and $3{\beta}$-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by ${\beta}-CA$ treatment, but only slightly improved by EA treatment. These findings indicate that ${\beta}-CA$, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

• 한국발생생물학회지:발생과생식
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• 제20권1호
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• pp.11-22
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• 2016

The ultrastructures of germ cells and the functions of Leydig cells and Sertoli cells during spermatogenesis in male Kareius bicoloratus (Pleuronectidae) were investigated by electron microscope observation. Each of the well-developed Leydig cells during active maturation division and before spermiation contained an ovoid vesicular nucleus, a number of smooth endoplasmic reticula, well-developed tubular or vesicular mitochondrial cristae, and several lipid droplets in the cytoplasm. It is assumed that Leydig cells are typical steroidogenic cells showing cytological characteristics associated with male steroidogenesis. No cyclic structural changes in the Leydig cells were observed through the year. However, although no clear evidence of steroidogenesis or of any transfer of nutrients from the Sertoli cells to spermatogenic cells was observed, cyclic structural changes in the Sertoli cells were observed over the year. During the period of undischarged germ cell degeneration after spermiation, the Sertoli cells evidenced a lysosomal system associated with phagocytic function in the seminiferous lobules. In this study, the Sertoli cells function in phagocytosis and the resorption of products originating from degenerating spermatids and spermatozoa after spermiation. The spermatozoon lacks an acrosome, as have been shown in all teleost fish spermatozoa. The flagellum or sperm tail of this species evidences the typical 9+2 array of microtubules.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.187-190
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• 1993

A study was conducted to compare and determine the incidence of ultrastructural alterations in the testes of Philippine carabaos and crossbred buffaloes. Thirteen Philippine carabao bulls and twenty five crossbred male buffaloes were used in this study. Testicular biopsy was used to get tissue samples which were prepared for histologic evaluation using the electron microscopy method. There was no significant difference in Sertoli cell alterations between Philippine carabaos and crossbred buffaloes. However, more crossbred buffaloes (40%) had both Sertoli cell and spermatogenic cell alterations which were significantly higher compared to the 7.7% occurrence in Philippine carabaos. Sertoli cells of crossbred buffaloes exhibited intracavitary structures and exaggerated infoldings of the nuclear envelope (36%), nuclear bleb (16%), and intracytoplasmic vacuolations (16%). Philippine carabaos exhibited few ultrastructural alterations which were mainly intracytoplasmic vacuolations in Sertoli cells (15%).

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제48차 춘계 학술대회
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• pp.111-111
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• 2005

• 대한방사선기술학회지:방사선기술과학
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• 제13권2호
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• pp.51-51
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• 1990

This study was undertaken to observe the effects of $^{60}Co\;{\gamma}-irradiation$ on the cell of spermatogenic epithelium in the testis of the chicken. 16-week-old chicken were provided as an experimental group and compared with control group. The experimental group was divided into a single irradiation (800, 1000, 1200 rads) and into three partial irradiation group (800/3, 1000/3, 1200/3 rads). The morphological changes of epithelial cell of the testis were observed by means of hematoxyline and eosin stain. Microstructure of spermatocyte and sperm was observed by means of semithin section of electron microscopic specimen. The results obstained are summerized as follows. 1. Spermatogonia and sertoli cells were found to be isolated from the basal membrane of seminiferous tubules as dose of $^{60}Co\;{\gamma}-irradiation$ was increased. 2. Spermatocytes of pachytene stage were seperated from the cytotplasmic process of sertoil cell in case of 1000 rads of $^{60}Co\;{\gamma}-irradiation$. 3. Normal arrangement of the cell of spermatogenic epithelium was found in control group and only the partial irradiation group of 800 rads. Vaculation in the seminiferous was pronounced in case of a single irradiation group of 800 rads, but the irradiation group of 1000 rads and 1200 rads were found to be damaged severely in both a single and a partial dose.

• Fisheries and Aquatic Sciences
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• 제10권3호
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• pp.143-149
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• 2007

This study describes spermatogenesis and sperm ultrastructure of the granular ark, Tegillarca granosa using light and electron microscopy. In the active spermatogenic season, the testis comprises many spermatogenic follicles that contain germ cells in different developmental stages. Primary spermatocytes in the pachytene stage are characterized by synaptonemal complexes. The early spermatids are characterized by the appearance of several Golgi bodies, increased karyoplasmic electron density, and tubular mitochondria. The mass of proacrosomal granules consists of numerous heterogeneous granules with high electron density that are about 20 nm in diameter. From the midstage of spermiogenesis, the well-developed mitochondria in the cytoplasm aggregate posterior to the nucleus and surround the proximal and distal centrioles. The proacrosomal granules condense and form a single acrosome with a thin envelope. During late spermiogenesis, the acrosome begins to elongate becoming conical. The sperm is approximately $35.0{\mu}m$ long and consists of a head, midpiece, and tail. The head comprises a round nucleus and a conical acrosome. A micro fibrous axial rod is observed between the nucleus and acrosome. The midpiece has a calyx-like structure with five mitochondria, and the tail, which has the typical "9+2" microtubular system, originates from the distal centriole.

• 대한임상검사과학회지
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• 제41권3호
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• pp.111-122
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• 2009

Cadmium (Cd) is known to exert gonadotoxic and spermiotoxic effects. The present study was performed to investigate the morphological effects and metallothionein (MT) expression by zinc pretreatment in the course of time of cadmium-induced testicular injury in rat. Fifty male Spraque-Dawley rats weighing 160~180 g were divided into two groups : saline-pretreated cadmium group and zinc-pretreated cadmium group. Rats of two groups received subcutaneous injection of saline and 100 mg/kg $ZnSO_4$ at 0, 2, 5 and 8 hrs intervals respectively. Cadmium chloride (4.5 mg/kg $CdCl_2$) was administrated intraperitoneally at 2 hrs after zinc injection and rats were killed 0, 12, 24, 48 and 72 hrs later. Testicular tissue damages, interstitial (Leydig) cells status and MT expression were determined using hematoxylin-eosin stained sections and a computerized image analysis system on sections immunostained with a mouse anti-metallothionein respectively. Zinc pretreatment was significantly reduced testicular damages in five pathological categories after cadmium administation. The number of surviving interstitial cells was significantly higher in the zinc-pretreated group than in the saline-preatreated group at 48 and 72 hrs after cadmium administration. Non-damaged testis showed the positivity of MT staining in spermatogenic cells, Sertoli cells and endothelium of blood vessel, but not in the Leydig cells. The positivity of MT staining in saline-pretreated group was significantly reduced at 24 hrs after cadmium administration, whereas zinc-pretreated group showed strong MT positive staining similar to the 0 hr by 42 hrs after cadmium administration. In damaged testis, MT positive staining was also observed in the Leydig cells of both groups. These results suggest that a major preventive effect of zinc against cadmium-induced testicular toxicity may be due to its ability to reduce the cytotoxicity of cadmium in spermatogenic cells and Leydig cells by inhibiting the susceptibility of the testis to cadmium but not MT production by cadmium.

• 대한임상검사과학회지
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• 제42권3호
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• pp.136-148
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• 2010

Cadmium (Cd) is known to exert gonadotoxic and spermiotoxic effects. The present study was performed to investigate the morphological effects and metallothionein (MT) expression by zinc pretreatment in the course of time of cadmium-induced testicular injury in rat. Fifty male Spraque-Dawley rats weighing 160-180 g were divided into two groups: saline-pretreated cadmium group and zinc-pretreated cadmium group. Rats of two groups received subcutaneous injection of saline and 100 mg/kg $ZnSO_4$ at 0, 2, 5 and 8 hrs intervals respectively. Cadmium chloride (4.5 mg/kg $CdCl_2$) was administrated intraperitoneally at 2 hr after zinc injection and rats were killed 0, 12, 24, 48 and 72 hrs later. Testicular tissue damages, Interstitial (Leydig) cells status and MT expression were determined using hematoxylin-eosin stained sections and a computerized image analysis system on sections immunostained with a mouse anti-metallothionein respectively. Zinc pretreatment was significantly reduced testicular damages in five pathological categories after cadmium administation. The number of surviving interstitial cells was significantly higher in the zinc-pretreated group than in the saline-preatreated group at 48 and 72 hrs after cadmium administration. Non-damaged testis showed the positivity of MT staining in spermatogenic cells, Sertoli cells and endothelium of blood vessel, but not in the Leydig cells. The potitivity of MT staining in saline-pretreated group was significantly reduced at 24 hrs after cadmium administration, whereas zinc-pretreated group showed strong MT positive staining similar to the 0 hr by 42 hrs after cadmium administration. In damaged testis, MT positive staining was also observed in the Leydig cells of both groups. These results suggest a major preventive effect of zinc against cadmium-induced testiculat toxicity may be due to its ability to reduce the cytotoxicity of cadmium in spermatogenic cells and Leydig cells by inhibiting the susceptibility of the testis to cadmium but not MT production by cadmium.