• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.451-458
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• 2007

This study was to investigate the effectiveness of pre-weaning injection of gonadotropin and scheduled fixed-time insemination on sow fertility. Sows were randomly assigned to receive gonadotropin 2 days before weaning, 1 day after weaning or none as control. In gonadotropin treated groups, half of sows were inseminated twice at 24 and 36 hours after onset estrus and half of sows were inseminated twice at scheduled fixed-time. Weaning to onset of estrus was the shortest in lactating sows injected with gonadotropin prior to weaning. Liter size was significantly higher in AI groups after detection of estrus, compared to fixed-time AI group. Results of these experiments indicated that injection of gonadotropin in lactating sows could initiate the final follicular development, and has potential to enhance the reintegration of estrus. Further researches are needed to define the relationship between reduced interval of wean to onset estrus and enhanced fertility in lactating sows.

• Journal of Aquaculture
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• v.9 no.1
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• pp.3-10
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• 1996

Ovulation of maturing female yellow puffer, Takifugu obscrus, was induced by using single injection of human chorionic gonadotropin (HCG) or gonadotropin releasing hormone-analogue (GnRH-A) $des-Gly^{10}[D-Ala^6]$ GnRH-ethylamide plus pimozide. The response was evaluated using the fertilization and embryo-formation rate after insemination and the gonadotropin (GTH) level in blood plasma using radioimmunoassay. In the fertilization and embryo-formation, maximal effects were recorded by using 1,000 IU/kg HCG or $10\;{mu}g/kg$ GnRH-A plus 5 mg/kr pimozide. Pimozide (1, 5 mg/kg) or GnRH-A treatment alone was not effective in elevation of GTH level, however combinations of these treatments were particularly effective. Injection of dopamine blocked the rapid elevation of plasma GTH levels of blood. These data suggest that yellow puffer secrete GnRH and gonadotropin-releasing-inhibiting factor during the spawning or the other period.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.219-224
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• 2009

Objective: Hypogonadotropic hypogonadism (HH) is an uncommon cause of male infertility. We investigated the outcome of gonadotropin therapy for restoring fertility and pregnancy outcomes in patients with HH. Methods: Medical charts of 10 infertile male patients with HH treated with gonadotropin were reviewed. Initial testicular volume were estimated. Semen analysis parameters (semen volume, sperm counts, motility), serum leutenizing hormone (LH), follicle stimulating hormone (FSH), total testosterone were determined before and after human chorionic gonadotropin/human menopausal gonadotropin (hCG/hMG) treatment. Differences were analyzed statistically. Results: Of 10 patients, 7 (70%) succeed at pregnancy (nature pregnancy in 4). Semen analysis parameters, serum FSH, and testosterone were increased significantly after treatment. The population was stratified according to initial testicular volume into a small testis subset (testicular volume less than 10 cc in 4) and a large testis subset (testicular volume 10 cc or greater in 6). Semen analysis parameters and serum testosterone were increased significantly after treatment in large testis subset. Conclusion: Infertile men with HH initiate and maintain spermatogenesis with gonadotropin (hCG/hMG alone or combined) therapy, thus gonadotropin therapy is good choice in infertile men with HH.

• 대한생식의학회:학술대회논문집
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• 2007.06a
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• pp.145-145
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• 2007

• Korean Journal of Animal Reproduction
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• v.19 no.1
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• pp.15-34
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• 1995

1970년말부터 뇌하수체 성선자극호르몬(gonadotropic hormone ; GTH)의 유전자 구조(FSH$\beta$, LH$\beta$ 및 공동의 $\alpha$쇄)가 다양한 종에서 밝혀지기 시작하였으나 이러한 유전자의 조직/세포 특이적 분비양식과 세포외 신호에 의한 조절양식은 정확히 밝혀져 있지 않다. 그러나 최근 들어 형질전환 맞추스 제작기법에 의해 $\alpha$쇄 유전자 상류에 세포특이적 발현을 조절하는 특이부위가 존재함이 보고됨을 시작, FSH$\beta$ 및 LH$\beta$쇄 유전자발현을 조절하는 특이부위 또한 가까운 시기내 발견되리라 기대된다. 한편, 성선자극 호르몬 방출호르몬(GnRH), 스테로이드 호르몬 및 여러 결합단백질과 같은 세포의 신호는 각기 다른 신호전달체계를 통하여 GTH유전자 발현을 일으킨다. 또한 뇌하수체에서도 그 존재가 확인된 전사인자들 (cFos, cJun)과 미지의 인자들은 상호간에 다양한 이량체를 형성하여 유전자 발현을 조절하는 각 특이부위에 결합함으로써 전사단계에서의 다양한 제어가 존재함이 밝혀지고 있으며 이러한 유전자상의 특이발현영역과 세포의 신호별 전사인자에 관한 연구는 번식에 있어 중요한 성선자극호르몬에 관한 분자수준의 조절기전을 밝혀내리라 기대되어진다.

• The Zoological Society Korea : Newsletter
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• v.16 no.1
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• pp.17-50
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• 1999

시상하부에 극히 적은 수로 존재하는 신경분비세포인 성선자극호르몬-방출호르몬(gonadotropin-releasing hormone; GnRH) 뉴런은인간을 포함한 포유동물의 생식과 발생 과정에 있어 중요한 역할을 담당하고 있다. GnRH 뉴런은 배아 발생과정 중에 후판에서 유래하여 시상하부의 여러 영역으로 이동하며, 생후와 사춘기를 거치면서 분화를 계속한다. GnRH 뉴런에서 합성, 분비되는 10개의 아미노산으로 이루어진 작은 신경호르몬인 GnRH는 맥동적으로 분비되어 뇌하수체 성선자극 세포막에 존재하는 GnRH 수용체와 결합한 후 일련의 신호전달과정을 거쳐 성선자극호르몬의 합성과 분비를 제어하게 된다. GnRH의 합성과 분비는 글루탐산, 노르에피네프린, GABA와 같은 각종 신경입력과 스테로이드 호르몬에 의한 액성 피드백 신호에 의해 조절되나 이들의 GnRH 유전자 발현에 미치는 영향은 최근에 연구되고 있는 실정이다. GnRH 뉴런의 분화와 발생에는 다양한 신경영양인자들이 영향을 미치나 그 분자생물학적 기작은 아직 밝혀져 있지 않다. 본 논단에서는 신경호르몬인 GnRH와 그 수용체에 관하여 최근 연구성과를 중심으로 살펴보고자 한다.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.208-208
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• 2004

임신초기 말의 태반으로부터 분비되는 융모성 성선자극 호르몬(eCG)은 황체형성(LH), 난포자극(FSH) 및 갑상선자극(TSH)호르몬과 같이 알파 및 베타 단체의 비공유결합으로 구성되어져 있는 당단백질 호르몬이다. 말의 융모성 성선자극 호르몬은 모체의 자궁내막에 침입한 태아 유래의 융모조직(자궁내막배)에서 합성ㆍ분비되어진다. 알파단체의 아미노산 배열은 동물종내에서 동일하지만, 베타단체는 호르몬에 따라 작용의 특이성을 가지고 있다고 알려져 있다. (중략)

• Development and Reproduction
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• v.7 no.1
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• pp.35-40
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• 2003

Gonadotropin releasing hormone(GnRH), which is secreted from the hypothalamus, has a pivotal role in the reproduction of mammals. Golden hamsters are seasonal breeding mammal and their sexual activity is determined by photoperiod(length of light per day). Long photoperiod(LP, $\leq$ 12.5 hours of light) maintains the reproductive activity and short photoperiod(SP, $\leq$ 12 hours of light) suppresses it. In order to investigate in detail, the sexual activity was individually examined in SP-housed male golden hamsters received a vector at three different concentrations which contains rat GnRH cDNA. The gonadal regression was significantly(P<0.05) accelerated by the highest concentrations of the vector at 8 and 10 weeks after the treatment in comparison to the other groups. In the light of pulsatile release of GnRH in maintaining reproductive activity, the vector containing GnRH cDNA might secrete the GnRH in a constant high level. These results suggest that the GnRH-containing vector might desensitize the anterior pituitary, leading to acceleration or testicular regression.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.2
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• pp.111-119
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• 2009

Objective: The aim of this study was to compare the clinical efficacy of clomiphene citrate (CC) and letrozole combined with gonadotropins for controlled ovarian stimulation (COS) in patients with CC-induced thin endometrium Methods: Fifty-one intrauterine insemination cycles performed in patients who previously had a thin endometrium (<8 mm) to ovulation induction using CC were included in this study. A CC 100 mg/day (CC+gonadotropin group, n=26) or letrozole 2.5 or 5 mg/day (letrozole+gonadotropin group, n=25) was administered on day 3~7 of the menstrual cycle, combined with gonadotropins at dose 75~150 IU every other day starting on day 5~7. We compared total dose of gonadotropin used, endometrial thickness, endometrial pattern, number of follicles ${\geq}14\;mm$ on hCG day, pregnancy rate and multiple pregnancy rate between the two groups, which were statistically analyzed using Mann-Whitney U test or Fisher's exact test, where appropriate. Results: There were no significant differences in clinical characteristics such as age, duration of infertility, number of previous IUI cycles, basal serum hormone levels and cause of infertility between the two groups. In both groups, the endometrium was significantly thicker than that of previous ovulation induction cycles using CC. No significant differences were found in the total dose of gonadotropin used, day of hCG administration, the rate of triple endometrium and pregnancy rate. The number of follicles ${\geq}14\;mm$ was significantly lower ($3.7{\pm}1.7$ vs. $2.8{\pm}1.7$, p=0.03) and the endometrium on hCG day was significantly thicker ($7.7{\pm}1.5$ vs. $9.1{\pm}1.7$, p=0.001) in letrozole+gonadotropin group compared to CC+gonadotropin group. Conclusion: The clomiphene citrate and letrozole combined with gonadotropins appear to avoid the undesirable effects on the endometrium frequently seen with CC for ovulation induction. However, in terms of adequate endometrial development or optimal follicular growth, letrozole may be more beneficial than CC for gonadotropin-combined COS in patients with CC-induced thin endometrium. Further prospective randomized controlled studies in a larger scale will be necessary to confirm our findings.

• Clinical and Experimental Pediatrics
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• v.52 no.12
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• pp.1370-1376
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• 2009

Purpose:Treatment of precocity with gonadotropin releasing hormone analogue (GnRHa) might theoretically exert a detrimental effect on the bone mass during pubertal development. We investigated the short-term changes in bone mineral density (BMD) during GnRHa treatment and the enhancement in the changes with the co-administration of GnRHa and human growth hormone (hGH). Methods:Forty girls with precocious or early puberty who were using GnRHa for more than 1 year were enrolled. Of them, 14 concurrently received hGH. Lumbar bone mineral density was measured before and after the treatment, and bone mineral density-standard deviation scores (BMD-SDSs) were compared according to chronologic age (CA) and bone age (BA), as well as according to the administration of GnRHa alone (Group I) or the co-administration of hGH and GnRHa (Group II). Results:BMDs before and after treatment were in the normal range according to CA but were significantly lower according to BA (P<0.05). During treatment, BMD-SDSs did not change according to CA but significantly increased according to BA (P<0.05). BMD-SDSs in group I did not change during treatment according to CA or BA, while those in group II increased significantly according to BA (P<0.05), but not according to CA. Conclusion:Lumbar BMD was adequate according to CA at initial manifestation of precocity but was lower if compared to BA, that is, BMD did not increase with BA. Because co-treatment with hGH significantly increased BMD-SDSs according to BA, hGH co-treatment could be considered during GnRHa therapy.