• Development and Reproduction
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• v.1 no.2
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• pp.157-164
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• 1997

To study the regulation of porcine follicular cell apostosis by gonadotropin, steroid, and nitric oxide, we analyzed DNA fragmentation, the hallmark of apoptosis, and nitrite production of porcine granulosa cells. Dissected indiidual follicles from ovary were separated in size (small, 2-3 mm; medium, 5-6 mm; large, 7-8 mm) and isolated granulosa cells were classified morpholocally as atretic or nonatretic. Nitrite concentration was measured by mixing follicular fluids with an equal volume of Griess reagent. Follicular nitric oxide (NO) concentration of healthy follicles was higher than that of atretic follicles. Apoptotic DNA fragmentation was suppressed in non-apoptotic granulosa cells. Follicular apoptosis was induced by androgen but prevented by gonadotropin in vitro. Apoptosis was confined to the granulosa cells. But it was not clear whether apoptosis of granulosa cells were isolated, incubated with or without gonadotropin, androgen and sodium nitroprusside (SNP), respectively at $37^{\circ}C$ for 24 hrs. Cultured granulosa cells were used to extract genomic DNA and culture media was asssayed for nitrite concentration. Nitrite production of culture media was increased, while apoptotic DNA fragmentation was suppressed in PMSG, hCG, testosterone+SNP and SNP treated groups. Nitrite concentration in culture media was decreased, but apoptotic DNA fragmentation was induced in testosterone treated group. These data suggest that NO production and apoptosis may be involved of granulosa cell apoptosis induced by testosterone.

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.15-18
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• 1983

As a preliminary experiment to establish the process of embryo transfer in rabbit, present sutdies were carried out with 75 mature Japanese of ovary to pregnant mare's serum gonadotropin(PMSG) and human chorionic gonadotropin(hCG) and collection rate of embryos at various times after hCG injection. Female rabbits were superovulated using 50∼100IU hCG or 75∼100IU PMSG and 50∼751IU hCG injected 83hrs apart. The results obtained were as follows: 1. The average number of growth follicles obtained from all of rabbits treated with hCG or PMSG-hCG was 28.1. PMSG-hCG treatment group (30.9) was clearly increased more than hCG treatment group (16.7). 2. In ovulation score, PMSG-hCG treatment group (21.0) was increased more than hCG treatment group (7.9), showing the same trends in the growth of follicles. 3. The ovulation rate per follicles developed was higher in the rabbits treated with 100 IU PMSG and 75 IU hCG (18.9%) than that from the other groups. 4. The oviduct score (72.9%) was inclined to higher than that from uteri (57.1%) in score of embryo collection.

• Advances in Traditional Medicine
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• v.4 no.2
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• pp.77-81
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• 2004

Petroleum ether, benzene and alcohol extracts of seeds of C. juncea administered orally at the dose level of 25mg/100g body weight to adult female mice for 30 days, resulted in irregular estrous cycle with prolonged estrus and metaestrus and reduced diestrus and proestrus during the experimental period. Histological studies of the ovary indicate increases in the number of atretic follicles but decreases in the number of developing follicles, Graafian follicles and corpora lutea. The total cholesterol content of the ovary is increased, whereas ascorbic acid content is decreased. The weight of the uterus and its micrometric measurement in all experimental mice are increased significantly. The alcoholic extracts showed estrogenic activity in immature mice by early opening of the vagina, premature cornification of the vaginal epithilium and increases in uterine weight. However, alcohol extract of seeds of C. juncea was more effective in causing these changes compared to other extracts. After subjecting to preliminary phytochemical screenings alcohol extract showed positive; test for alkaloids, steroids, glycosides, flavones, phenols and tannins.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.95-95
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• 2003

Endocrine factors, such as steroid hormones and growth factors, regulate egg productivity including the number of egg production, egg weight, sexual maturity, and the number of small yellow follicles. Especially, insulin-like growth factor-I (IGF-I) is involved in the regulation of ovulation rate and ovarian follicular development in chickens, and the relationship between IGF-I genotype and egg weight was reported. However, the effect of grwoth factors on egg productivity in Korean Native Ogol Chicken (KNOC) has not been studied. Therefore this study was conducted to identify the relationship among endocrine factors, IGF-I genotypes, and egg productivity. IGF-I genotypes (AA, AB, BB) were represented to 12.6%, 34%, and 53.4%, respectively. AB genotype stimulates the secretion of estradiol and progesterone in serum (30 and 40 week), regulates growth and proliferation of follicles at 60 weeks, and is positively associated with the number of small yellow follicles. Therefore, these results suggest that there are possibility to IGF-I genotypes for a genetic marker in egg productivity of KNOC.

• 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.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.175-182
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• 1990

Progesterone production and oocyte maturation in ovarian follicles of Rana nigromaculata and Rana rugosa were investigated. Addition of frog pituitary homogenate (FPH) to the in utiro cultured follicles of R. nigromaculata stimulated a marked increase in the accumulation and secretion of progesterone (P$_4$) by the follicles and induced their oocyte maturation (germinal vesicle breakdown, GVBD) in a dose dependent manner. The FPH (0.1 pituitary equivalent/2 ml)-inducted P4 peak appeared in 3-6 hours and followed by the oocyte GVBD in 9-12 hours after the hormone stimulation. lncreae of intrafollicular cAMP levels with forskolin (an adenylatecyclase stimulator) and 3-isobutyl-1-methylxanthine (IBMX, a phosphodiesterase inhibitor) mimic the FPH action in the stimulation of P$_4$ production but not in the induction of oocyte maturation. The in uitro cultured follicies of R. rugosa behaved very differently from other amphibian follicles. Addition of FPH-(0. 1 pit. equivl2 ml) to the culture medium neither stimulated P$_4$ production by the follicles nor induced the oocyte GVBD. However, treatment of the follicles with forskolin and IBMX drastically stimulated both the intrafollicular accumulation (800 pg/follicle) and secretion (1700 pg/follicle) of P$_4$ by the follicles during culture period. Thus, the data suggest that the follicles are ready to respond to cAMP increase but not to the FPH stimulation in terms of P$_4$ production.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.54-57
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• 2016

Controlled ovarian hyperstimulation is one of the major steps of in vitro fertilization. The inaccessibility or non-visualization of developing follicles on transvaginal sonography (the preferred imaging method) may be misjudged as a poor response, resulting in cycle cancellation. It is necessary to scrupulously appraise proxy indicators for ovarian response, such as estradiol levels, endometrial thickness, and other individual clinical characteristics. This can prompt meticulous transabdominal ultrasound follicular monitoring and oocyte retrieval with the goal of averting cycle cancellation and improving treatment outcomes.

• Reproductive and Developmental Biology
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• v.28 no.3
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• pp.147-153
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• 2004

The oocyte and its surrounding granulosa cells co-exist in a closed compartment called a follicle, although they receive many signals from other parts of the body. It is well established that the intercellular communications between the oocyte and granulosa cells are required for normal oocyte development and ovulation during folliculogenesis. Gap junctions are intercellular channels allowing the direct transmission of ions and small molecules between coupled cells. Several lines of studies have shown that multiple connexins (Cx, subunits of gap junction) are expressed in mammalian ovarian follicles. Among them, two major connexins Cx37 and Cx43 are expressed in different manner. While the gap junction channels formed by Cx37 are localized between the oocyte and encompassing granulosa cells, the intercellular channels by Cx43 are located between granulosa cells. In this review, I will summarize the general properties of gap junction channels and discuss their possible formation (or compatibility) of intercellular channels formed by the oocyte and granulosa cells.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.183-188
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• 2021

In vitro maturation (IVM) of oocytes is the procedure where the immature oocytes are cultivated in a laboratory until they are mature. Since IVM oocytes generally have low developmental competence as compared to those matured in vivo, development of an optimal IVM culture system by fine-tuning culture conditions is crucial to maintain high quality. In-depth knowledge and a deep understanding of the in vivo physiology of oocyte maturation are pre-requisites to accomplish this. Within ovarian follicles, various signaling pathways that drive oocyte development and maturation regulate interaction between oocytes and surrounding somatic cells. This review discusses the sonic hedgehog (SHH) signaling pathway, which has been demonstrated to be intimately involved in folliculogenesis and oocyte maturation. Advances in elucidating the role of the SHH signaling pathway in oocyte maturation will aid attempts to improve the current inferior in vitro oocyte maturation system.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.3
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• pp.231-238
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• 2008

Objective: Significant portion of premature ovarian failure patients ovulate intermittently and even can achieve pregnancy. The clinical features and reproductive potentials of Korean women with premature ovarian failure have never been elucidated. The purpose of this study is to assess ovarian follicular growth and ovulatory potential. Methods: Complete medical records of fifteen women with idiopathic premature ovarian failure were reviewed retrospectively. Subjects with more than 6 ultrasonographic scans and 36 months of follow-up period were included. Once the ovarian follicle was found by ultrasonography, the follicular growth was serially monitored. The result of ovulation induction of 6 cycles in 4 patients were also evaluated. Rate of positive ovarian follicle by ultrasound, rate of natural follicular growth and response of ovulation induction were assessed. Results: Among the 15 patients, 6 women (40%) had ovarian follicle in random ultrasonography. But the chance of positive follicle per ultrasonography scan was 7% (8 out of 115 scans). One out of 6 women eventually ovulated during the follow-up scan. In remaining 5 subjects, size of follicles remained unchanged. None of 6 ovulation induction cycles resulted successful ovulation. Conclusion: Incidence of positive ovarian follicle in Korean premature ovarian failure patients is lower than that of Western counterpart. This result, however, could not be directly compared because of the differences of study design. The ovulation rate by medical ovulation induction in this group is 0%, which is worse than the reported success rate of Western studies.