• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1211-1216
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• 2011

Sexual maturity in poultry is controlled by a complex neural circuit located in the basal forebrain, which integrates the central and peripheral signals to activate hypothalamic gonadotrophin-releasing hormone (GnRH) secretion. This study demonstrated the changes of GnRH-I, POMC and NPY mRNA transcription in hypothalamus and IGF-I and leptin levels in serum of Shaoxing ducks during puberty. Body weight increased progressively from d30 to d120 and at d120 the flock reached 5% of laying rate. A significant upregulation of hypothalamic GnRH-I mRNA expression was observed from d60, reaching the peak at d120. POMC and NPY mRNA expression in hypothalamus showed a similar pattern, which increased from d30 to d60, followed by a significant decrease towards sexual maturity. Serum IGF-I levels exhibited two peaks at d30 and d120, respectively. Serum leptin displayed a single peak at d90. The results indicate that the down-regulation of POMC and NPY genes in hypothalamus coincides with the up-regulation of GnRH-I gene to initiate sexual maturation in ducks. In addition, peripheral IGF-I and leptin may relay the peripheral metabolic status to the central system and contribute to the initiation of the reproductive function in ducks.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2003년도 제45차 추계학술대회
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• pp.121-121
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• 2003

• Ocean and Polar Research
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• 제38권1호
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• pp.81-88
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• 2016

In many fish species, including Nile tilapia (Oreochromis niloticus), gonadal development occurs at the expense of stored energy and nutrients. Therefore, reproductive systems are inhibited by limited food supply. It has been well established that reproductive function is highly sensitive to both metabolic status and energy balance. Nothing is known about the possible mediated connection between energy balance and reproduction. Kisspeptin, a neuropeptide product of the Kiss gene has emerged as an essential gatekeeper of reproduction and may be possibly be linked to energy balance and reproduction in non-mammalians. Thus, in this study, the effect of fasting (10 days) on the expression of kisspeptin and the gonadotropin-releasing hormone (GnRH) gene were assessed in Nile tilapia (male and female) using qRT-PCR. In addition, plasma levels of estradiol-$17{\beta}$ ($E_2$) and 11-ketotestosterone (11-KT) in adult tilapia were measured by ELISA. In male tilapia, fasting reduced Kiss2 and GnRH I mRNA expression in the brain and 11-KT level in comparison with the fed tilapia (p < 0.05). In females, however, there were no significant differences in GnRH I mRNA expression and $E_2$ between fish subjected to fasting and those fed (p > 0.05). These data indicate the impact of nutritional states on kisspeptin as a potential regulatory mechanism for the control of reproduction in male Nile tilapia.

• Clinical and Experimental Reproductive Medicine
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• 제41권4호
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• pp.158-164
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• 2014

Objective: To assess whether an early GnRH antagonist start leads to better follicular synchronization and an improved clinical pregnancy rate (CPR). Methods: A retrospective cohort study. A total of 218 infertile women who underwent IVF between January 2011 and February 2013. The initial cohort (Cohort I) that underwent IVF between January 2011 and March 2012 included a total of 68 attempted IVF cycles. Thirty-four cycles were treated with the conventional GnRH antagonist protocol, and 34 cycles with an early GnRH antagonist start protocol. The second cohort (Cohort II) that underwent IVF between June 2012 and February 2013 included a total of 150 embryo-transfer (ET) cycles. Forty-three cycles were treated with the conventional GnRH antagonist protocol, 34 cycles with the modified early GnRH antagonist start protocol using highly purified human menopause gonadotropin and an addition of GnRH agonist to the luteal phase support, and 73 cycles with the GnRH agonist long protocol. Results: The analysis of Cohort I showed that the number of mature oocytes retrieved was significantly higher in the early GnRH antagonist start cycles than in the conventional antagonist cycles (11.9 vs. 8.2, p=0.04). The analysis of Cohort II revealed higher but non-significant CPR/ET in the modified early GnRH antagonist start cycles (41.2%) than in the conventional antagonist cycles (30.2%), which was comparable to that of the GnRH agonist long protocol cycles (39.7%). Conclusion: The modified early antagonist start protocol may improve the mature oocyte yield, possibly via enhanced follicular synchronization, while resulting in superior CPR as compared to the conventional antagonist protocol, which needs to be studied further in prospective randomized controlled trials.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2004년도 제47차 추계학술대회
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• pp.35-36
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• 2004

• 한국수산과학회지
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• 제32권2호
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• pp.204-210
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• 1999

본 연구에서는 GTH I과 II의 분비조절기구을 밝히기 위하여 T을 경구투여한 미성숙 무지개 송어의 뇌하수체 세포배양계를 이용하여, activin에 의한 GTH I과 II의 분비량을 RIA로 조사하였다. 그 결과, T의 positive feedback에 의해 뇌하수체내 GTH II 함량이 증가하였으나, 뇌하수체내 GTH I 함량는 T에 의해 영향을 받지 않았다. 이러한 뇌하수체를 이용한 세포배양 실험에서, 장시간 (3 일간)의 activin 처리에 의해 GTH II 분비량은 증가하였지만, 단시간 (24시간)의 activin 처리에 의해 GTH II 분비량은 영향을 받지 않았다. 또한 activin의 자극에 의해서 분비된 GTH II 분비량은 DA에 의해 부분적으로 억제되었지만, sG-nRH의 자극에 의해서 분비된 GTH II는 DA에 의해 완전히 억제되었다. activin의 자극에 의해서 분비된 GTH II는 부분적으로 억제되었다. 그러나 activin으로 전처리에 의해 방출된 GTH II 분비량은 sGnRH 자극에 의한 증폭현상은 나타나지 않았다. 한편 GTH I 분비는 본 실험에서 사용된 호르몬에 의해서 영향을 받지 않았다. 이상의 결과들을 종합해보면, GTH I과 II는 서로 다른 합성기구에 의해 조절되며, T에 의해 GnRH, activin 그리고 DA 수용체의 감수성이 발현되어 GTH II 분비를 조절하였다. 그러나 GTH I의 분비조절 기구는 차후 계속해서 연구되어야 할 것으로 판단된다.

• Clinical and Experimental Reproductive Medicine
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• 제26권3호
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• pp.389-398
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• 1999

Objective: This study was designed to evaluate the effects of endogenous LH surge, GnRH agonist (GnRH-a) or human chorionic gonadotropin (hCG) as ovulation trigger on pregnancy rate by intrauterine insemination (IUI). Method: Patients received daily 100 mg of clomiphene citrate (CC) for 5 days starting on the third day of the menstrual cycle followed by human menopausal gonadotropin (hMG) for ovulation induction. Follicles larger than >16 mm in diameter were present in the ovary, frequent LH tests in urine were introduced to detect an endogenous LH surge. Final follicular maturation and ovulation were induced by GnRH-a 0.1 mg (s.c.) or hCG $5,000{\sim}10,000$ IU (i.m.) administration except natural ovulation. Pregnancy was classified as clinical if a gestational sac or fetal cardiac activity was seen on ultrasound. Results: There were no differences in age, duration of infertility and follicle size, but more ampules of hMG were used in GnRH-a group compared to hCG 10,000 IU treated group (p<0.05). Lower level of estradiol ($E_2$) on the day of hCG or GnRH-a injection was observed in hCG 10,000 IU group than other treatment groups (p<0.01). The overall clinical pregnancy rate was 19.8% per cycle (32/162) and 22.2% per patient (32/144). Pregnancy rate was higher in natural-endogenous LH surge group (37.5%, 9/24) than GnRH-a (18.8%) or hCG treated group (20.9% & 13.9%), but this difference was not statistically significant. No patient developed ovarian hyperstimulation. Abortion rate was 22.2% (2/9) in hCG 5,000 IU group. Delivery or ongoing pregnancy rate was 37.5% (9/24), 18.8% (3/16), 16.3% (7/43) and 13.9% (11/79) in endogenous LH surge, GnRH-a, hCG 5,000 IU and hCG 10,000 IU treatment groups, respectively. Conclusion: These results support the concept that use of natural-endogenous LH surge in stimulated cycles may be more effective to obtain pregnancies by IUI than GnRH-a or hCG administration.

• Clinical and Experimental Reproductive Medicine
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• 제32권4호
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• pp.315-324
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• 2005

Objectives: To compare the efficacy of GnRH antagonist multiple dose protocol (MDP) with that of GnRH agonist long protocol (LP) in controlled ovarian hyperstimulation for in vitro fertilization in patients with high basal FSH (follicle stimulating hormone) level or old age, a retrospective analysis was done. Methods: Two hundred ninety four infertile women (328 cycles) who were older than 41 years of age or had elevated basal FSH level (> 8.5 mIU/mL) were enrolled in this study. The patients had undergone IVF-ET after controlled ovarian hyperstimulation using GnRH antagonist multiple dose protocol (n=108, 118 cycles) or GnRH agonist long protocol (n=186, 210 cycles). The main outcome measurements were cycle cancellation rate, consumption of gonadotropins, the number of follicles recruited and total oocytes retrieved. The number of fertilized oocytes and transferred embryos, the clinical pregnancy rates, and the implantation rates were also reviewed. And enrolled patients were divided into three groups according to their age and basal FSH levels; Group A - those who were older than 41 years of age, Group B - those with elevated basal FSH level (> 8.5 mIU/mL) and Group C - those who were older than 41 years of age and with elevated basal FSH level (> 8.5 mIU/mL). Poor responders were classified as patients who had less than 4 retrieved oocytes, or those with $E_2$ level <500 pg/mL on the day of hCG injection or those who required more than 45 ampules of exogenous gonadotropin for stimulation. Results: The cancellation rate was lower in the GnRH antagonist group than in GnRH agonist group, but not statistically significant (6.8% vs. 9.5%, p=NS). The amount of used gonadotropins was significantly lower in GnRH antagonist group than in agonist group ($34.8{\pm}11.3$ ampules vs. $44.1{\pm}13.4$ ampules, p<0.001). The number of follicles > 14 mm in diameter was significantly higher in agonist group than in antagonist group ($6.7{\pm}4.6$ vs. $5.0{\pm}3.4$, p<0.01). But, there were no significant differences in clinical pregnancy rate (24.5% in antagonist group vs. 27.4% in agonist group, p=NS) and implantation rate (11.4% in antagonist group vs. 12.0% in agonist group, p=NS) between two groups. Mean number of retrieved oocytes was significantly higher in GnRH agonist LP group than in GnRH antagonist MDP group ($5.4{\pm}3.5$ vs. $6.6{\pm}5.0$, p<0.0001). But, the number of mature and fertilized oocytes, and the number of good quality (grade I and II) and transferred embryos were not different between two groups. In each group A, B, and C, the rate of poor response did not differ according to stimulation protocols. Conclusions: In conclusion, for infertile women expected poor ovarian response such as who are old age or has elevated basal FSH level, a protocol including a controlled ovarian hyperstimulation using GnRH antagonist appears at least as effective as that using a GnRH agonist, and may offer the advantage of reducing gonadotropin consumption and treatment period. However, much work remains to be done in optimizing the GnRH antagonist protocols and individualizing these to different cycle characteristics.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2002년도 제43차 추계학술대회
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• pp.65-66
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• 2002

• Clinical and Experimental Reproductive Medicine
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• 제38권4호
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• pp.228-233
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• 2011

Objective: To investigate the effectiveness of GnRH antagonist multiple-dose protocol (MDP) with oral contraceptive pill (OCP) pretreatment in poor responders undergoing IVF/ICSI, compared with GnRH antagonist MDP without OCP pretreatment and GnRH agonist low-dose long protocol (LP). Methods: A total of 120 poor responders were randomized into three groups according to controlled ovarian stimulation (COS) options; GnRH antagonist MDP after OCP pretreatment (group 1), GnRH antagonist MDP without OCP pretreatment (group 2) or GnRH agonist luteal low-dose LP without OCP pretreatment (group 3). Patients allocated in group 1 were pretreated with OCP for 21days in the cycle preceding COS, and ovarian stimulation using recombinant human FSH (rhFSH) was started 5 days after discontinuation of OCP. Results: There were no differences in patients' characteristics among three groups. Total dose and days of rhFSH used for COS were significantly higher in group 3 than in group 1 or 2. The numbers of mature oocytes, fertilized oocytes and grade I, II embryos were significantly lower in group 2 than in group 1 or 3. There were no significant differences in the clinical pregnancy rate and implantation rate among three groups. Conclusion: GnRH antagonist MDP with OCP pretreatment is at least as effective as GnRH agonist low-dose LP in poor responders and can benefit the poor responders by reducing the amount and duration of FSH required for follicular maturation.