• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.571-584
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• 2004

It is known widely that granulosa cell apoptosis leads follicular atresia and macrophages exert their effects directly and/or indirectly from the initiation to the completion of follicular atresia by phagocytosis of apoptotic bodies and secretion of various cytokines. However, the site of initiation, propagation routes and the elimination methods of apoptotic bodies, and the time and methods of penetration of macrophages into the follicles are not known completely. Using pig(Yorkshire-breed) ovary, immunohistochemical studies with TUNEL for apoptotic bodies and pig macrophage monoclonal antibody 4E9 for macrophages, and light and transmission electron microscopic observations were performed. In the pig, follicular atresia began with the granulosa cell apoptosis, and the apoptosis of theca intema cells occured at the same time. The apoptosis of granulosa cells initiated randomly within the granulosa cell layer and propagated rapidly into the whole layer. Ultrastructura1ly, apoptotic granulosa cells showed characteristic pyknotic and deformed nucleus and intracytoplasmic vesicles. Apoptotic bodies were eliminated by intact granulosa cells and macrophages. Intact granulosa cells ingested apoptotic bodies transiently, soon after they fell into the apoptosis. Finally, apoptotic bodies and degenerated oocyte were phagocytosed by macrophages. Macrophages entered the ovarian follicle at the time of initiation of granulosa cell apoptosis, and migrated with the progression of apoptosis. By elimination of theca cells, macrophages contributed the completion of follicular atresia These results will provide valuable informations on the study of the interrelation between macrophage and ovarian follicular atresia.

• Journal of Radiation Protection and Research
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• v.24 no.1
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• pp.17-22
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• 1999

This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on mouse ovarian follicles. Immature mice (ICR, 3 week-old) were irradiated with a dose of $LD_{80(30)}$ at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. With the morphological basis of the histological staining with hematoxylin-eosin, immunohistochemical preparation using in situ 3'-end labeling was evaluated. Flowcytometric evaluation of DNA extracted from the whole ovary was performed. The percentage of $A_0$ (subpopulation of cells with degraded DNA and with lower DNA fluorescence than $G_0/G_1$ cells), apoptotic, cells in the cell cycle was significantly higher in the irradiated group than in the control group. The number of in situ 3'-end labeled follicles increased at 6 hours post irradiation. All the analyses represented that the ionizing radiation-induced follicular atresia was taken place via an apoptotic degeneration. Such a degeneration underwent very fast and acutely. Therefore, it is concluded that the radiation-induced follicular degeneration is, like the spontaneous atresia, mediated by an acute apoptosis of follicular granulosa cells. Flowcytometric evaluation of cell cycles can make the role for quantifying the atretic follicles and understanding the mechanism of the radiation-induced cell death.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.1
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• pp.69-79
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• 1989

Steroid hormone profiles during luteal phase of clomiphene citrate(CC)/human menopausal gonadotropin(hMG)/human chorionic gonadotropin(hCG)-stimulated in vitro fertilization (IVF) cycles and of follicle-stimulating hormone(FSH)/hMG/hCG-stimulated IVF cycles were compared. In seventy three cycles stimulated with CC/hMG/hCG regimen, follicles were aspirated during exploratory laparotomy and yielded 7 pregnancies, and in 83 cycles stimulated with FSH/hMG/hCG regimen, follicles were aspirated by laparoscope and made 13 pregnancies. Serum estradiol($E_2$) and progesterone($P_4$) levels were determined on days 2, 5, 7, and 9 after follicle aspiration. The FSH/hMG/hCG regimen was more effective than the CC/hMG/hCG regimen in folliculogenesis, ie, ovarian stimulation, follicular phase $E_2$ peak levels, oocyte maturation, and the number of retrieved oocytes. There was no significant difference between luteal serum $P_4/E_2$ ratio of the two regimens, suggesting that secretory endometrial build-up ability for implantation may not differ each other. Several significant correlations were observed between follicular phase seum $E_2$ peak levels and luteal phase serum $E_2$ and $P_4$ levels in the FSH/hMG/hCG-stimulated cycles but any correlation was not significant in the CC/hMG/hCG-stimulated cycles, suggesting that somewhat more follicles may eventually fall in atresia even after attaining dominant stage in the CC/hMG/hCG-stimulated cycles than the FSH/hMG/hCG-stimulated cycles.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.1
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• pp.35-35
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• 2006

Objective: The purposes of the present study were to investigate the effect of ${\gamma}$-radiation on the expression of inhibin-${\alpha}$ proteins and genes for inhibin ${\alpha}$, ${\beta}A$, and ${\beta}B$ in the ovary. Methods: Immature mice were whole-body ${\gamma}$-irradiated with 25% of a lethal dose. At time 0, 3, 6, 12, and 24 hours after the irradiation, the ovaries were collected and used for immunohistochemistry for inhibin-${\alpha}$, and RT_PCR for inhibin-${\alpha}$, ${\beta}A$, and ${\beta}B$. Results: The expression of the immunoreactive inhibins-${\alpha}$ was maintained at 12 hours post-irradiation and reduced thereafter. The expression of inhibin-${\alpha}$ mRNA was significantly increased with the time after the irradiation. However there were no significant changes in the expression of ${\beta}A$ and ${\beta}B$ mRNAs. Conclusion: It might be thought that inhibin acts as one of the regulatory factors in the ${\gamma}$-radiation-induced follicular atresia in mice

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.385-393
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• 1997

다세포 생물에서 몸의 효율적 생존을 위한 각 기관의 homeostasis는 세포 증식과 사망에 의해 조절된다. 따라서, apoptosis라 명명된 세포사망은 정교한 기전에 의한 능동적이고 자발적인 사망기전으로써 몸의 정상적 유지를 위한 필수적인 현상이다. 발생기 세포나 신경세포 또는 흉선세포 분화 동안 과다한 세포의 제거가 apoptosis의 대표적인 예이며, 각종 호르몬에 의해 그 기능이 조절되는 난소세포에서도 apoptosis가 활발히 일어난다. Rat난소에는 태어날 때 수십 만개의 난포를 지니고 있는데, 이 중 단지 1%만이 배란에 사용되어질 뿐이고 나머지는 모두 사망하게 된다. 이러한 난포사망은 난소의 적절한 세포 수를 유지하기 위한 필수적 과정이며, 인위적으로 apoptosis를 억제하는 유전자인 bcl-2를 과다 발현시키면 난소암이 발생하는 연구결과가 이를 입증해주고 있다. 이처럼 중요한 난포 사망기전은 apoptosis라는 개념이 정립되면서 최근 들어 점차 그 연구가 활발해지고 있다. Apoptosis의 특징 중 뚜렷한 점은 DNA가 일정한 간격으로(180∼200 bp)잘려지는 DNA fragmentation현상으로, 이를 이용하여 DNA3'-end 부위에 방사선동위원소를 label한 후 이를 전기영동으로 분리하면 apoptosis를 손쉽게 측정할 수 있다. 난소의 기능은 시상하부호르몬인 LH와 FSH 뿐만 아니라 난소에서 분비되는 각종 난소국부호르몬들에 의해 조절된다. 특정한 발육단계의 난포는 특정한 호르몬에 의해 그 기능을 조절 받는데, 이러한 난소기능 조절기작은 매우 복잡한 경로를 지니고 있다. 이러한 복잡한 기작으로 인해 초기 연구에서첨 생체 내에서 밝히려는 연구 시도는 어려움에 부딪치게 되었다. 생체내 실험은 난소가 다양한 발육단계의 난포를 동시에 지니고 있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.

• Development and Reproduction
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• v.8 no.1
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• pp.27-33
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• 2004

To investigate the mechanism of germ cell death in postnatal stage of mouse, the involvement of apoptotic executioners, caspase-3 and caspase-activated DNase(CAD), and apoptotic initiators, Bax Fas and Fas ligand, in the germ cell death has been studied. Immune-labels of active caspase-3 and CAD were located in TUNEL-positive, apoptotic, oocytes as well as normal oocytes of primary or secondary follicles. CAD immune-labels were also detected in the nucleus of TUNEL-positive oocytes. Most of oocytes showing positive immune-labeling of active caspase-3 or CAD had vacuoles in their cytoplasm, which is the morphological characteristic of oocyte during folliclar atresia. Bax immune-stains were detected in the atretic oocytes which showed the vacuole in their cytoplasm. Positive immune-labels for Fas ligand was localized in TUNEL-positive or atretic oocytes. Presence of immunoreactivity of active caspase-3 and CAD in TUNEL-positive germ cells implicate that active raspase-3 and CAD might play a role in germ cell apoptosis during early development of mouse ovarian follicle. Immunohistochemical localization of Bax and Fas ligand in TUNEL-positive oocytes suggests that these might be the most plausible modulator of oocyte apoptosis.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.281-289
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• 1989

The present study was disigned to determine the concentration of bioavailable steroid hormones in the atretic follicular fluid (FF). The concentradons of progesterone (P), testosterone (T), estradiol (E), androstenedione (A), and 5-$\alpha$ dihydrotestosterone (DIlT) were determined by the established methods of luminescent immunoassay (LIA) or radioimmunoassay (RIA). Concentrations of T, A and Diff in human FF from smail (< 6 mm). medium (8-15 mm), and large (> 15 mm) atretic follicles were significandy higher than those of normal ones (p < 0.01). However, the levels of T, A and DHT in smail atretic foflicle were significandy lower than those found in normal one. The concentrations of P in atretic FF from porcine small (< 3 mm), medium (4-6 mm), and large (> 7 mm) follicles were not different from that of normal ones. However, the concentration of E in atretic forncles of each group was significantly lower than that of normal group (p < 0.001 in each group). On the other hand, the percentages of bioavailable T (BI) in human FF were significandy (p <0.001) higher than those in normal groups. The BT in normal or atretic FF was more than 90 % of total T. The present result demonstrates that the bioavailable androgen, but not E levels in atretic follicles is higher than that of normal one, and that the atretic mechanism might be dependent on the ovarian forncle size in the developmental stage and on the animal model system. Moreover, the present study suggests that the steroids found in the FF are the bioavailable forms and the concentration of BT in FF could be used as one of the valuable criteria classifying the ovarian atretic follicle.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.9-16
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• 2021

Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.395-406
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• 2000

The present study was conducted to examine the developmental capacity of mouse oocytes within prenatal follicles cultured various concentrations of FSH and LH and the expression of cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and cytochrome P450 17 $\alpha$ -hydroxylase (P450)$_{17{\alpha}}$ mRNA, as luteinization and atretic marker, in these culture conditions. In addition, we investigated the concentrations of progesterone and testosterone in culture medium. The developmental potential up to blastocyst of the oocytes grown in vitro was higher in the FSH alone (30.2%) and 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated (28.0%) groups than in the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group (22.0%). And the mean numbers of cell per blastocyst was higher in the FSH alone (50.9$\pm$26.1) and 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated (51.0$\pm$21.1) groups when compared to the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group (45.2$\pm$15.1). The expressions of P450scc and P450$_{17{\alpha}}$ mRNA in the oocyte -cumulus complexes were increased with increasing of LH concentration, and also the secretions of progesterone and testosterone were increased. Especially, in the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group, the expression of P450scc and P450$_{17{\alpha}}$ were significantly increased, and the secretion of progesterone and testosterone were significantly increased. Therefore, these data show that gonadotrophins are essential for the in vitro culture of preantral follicles, but that increasing of LH concentration is reduced the developmental capacity of oocytes. The cause of these findings may be due to increasing of progesterone and testosterone secretion by the enhance of P450scc and P450$_{17{\alpha}}$ mRNA expressions, as markers of luteinization and atresia. Conclusively, this study suggest that supplementation of 100 $m\ell$U/$m\ell$ FSH or 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH may be optimal condition for the culture of mouse pre antral follicles.