• Title/Summary/Keyword: Gonadotropin releasing

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Effect of Gonadotropin on the Expression of GnRH and GnRH mRNA in Rat Ovary (성선자극호르몬이 흰쥐 난소의 GnRH와 GnRH mRNA의 발현에 미치는 영향)

  • Paik, Won-Young;Chung, Pa-Jin;Park, Shin-Keun;Kim, Wan-Young;Lee, Jong-Hak;Kim, Jong-Hwa;Kim, Myeong-Ok;Choi, Wan-Sung
    • Clinical and Experimental Reproductive Medicine
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    • v.21 no.1
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    • pp.121-130
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    • 1994
  • Expression of gonadotropin releasing hormone(GnRH) has been described in the rat ovary. It remains, however, unkown whether GnRH is synthesized as a prohormone. Therefore, this study was performed to verify the expression of pro-GnRH by in situ hybridization and further to investigate the effect of gonadotropin on GnRH or GnRH mRNA in rat ovary by immunohistochemical and in situ hybridization techniques. Adult female Sprague-Dawely rats were used and the estrous cycle was synchronized by intraperitoneal injection of pregnant mare's serum gonadotropin(PMSG). Ovaries were fixed with 4% paraformaldehyde and embedded with G.C.T. compound and cut by cryostat. For immunohistochemistry, avidin-biotin peroxidase complex(ABS) method was employed and for in situ hybridization, $^{35}S$-end labeled oligonucleotide was used and followed by autoradiography. By in situ hybridization using GnRH oligomer and GAP(GnRH associated protein) oligomer, GnRH mRNA and GAP mRNA were co-localized in the fullicular cells, luteal cells, interstitial cells and theca cells. GnRH or GnRH mRNA signals in the ovary increased by human chorionic gonadotropin(hCG) injection. At the 3 and 6 hrs after hCG injection, the number of GnRH and GnRH mRNA containing cells increased rapidly and the density of GnRH and GnRH mRHA culminated at 9 hrs after heG injection. With the follicular development, the high expression of GnRH and GnRH mRNA was also observed within the follicles. After ovulation, the density of GnRH or GnRH mRNA decreased in the follicles but increased in the corpus lutea.

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Effect of Vinclozolin Administration on the Gene Expressions in Hypothalamus-Pituitary Axis of Immature Female Rats (미성숙 암컷 흰쥐 시상하부-뇌하수체 축 상의 유전자 발현에 미치는 Vinclozolin 투여 효과)

  • Lee, Woo-Cheol;Lee, Sung-Ho
    • Development and Reproduction
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    • v.12 no.1
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    • pp.97-105
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    • 2008
  • Vinclozolin (VCZ) is a systemic fungicide commonly used in fruits, vegetables and the wine industry. VCZ and its metabolites, butenoic acid (M1) and enanilide (M2) derivatives, act as anti-androgens through actions on the androgen receptor. Although there is growing body of evidence that VCZ's action as an endocrine disrupting chemical (EDC) in male reproductive physiology and pathphysiology, no evidence on the VCZ's EDC action in female is available yet. Previously we found that the prepubertal VCZ exposures could effectively delay the onset of puberty in female rats, suggesting the postponed or weakened activities of hypothalamus-pituitary-ovary (H-P-O) reproductive hormonal axis. The present study was performed to examine whether the VCZ administration affects the transcriptional activities of reproductive hormone-related genes in the same animal model. VCZ (10 mg/kg/day) was administered daily from postnatal day 21 (PND 21) through the day when the first vaginal opening (V.O.) was observed. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus and pituitary, total RNAs were extracted and applied to the semiquantitative reverse transcription polymerase chain reaction (RT-PCR). As a result, treatment with VCZ significantly lowered the transcriptional activity of nitric oxide synthase-2 (NOS-2) which is known to adjust gonadotropin-releasing hormone (GnRH) secretion in the hypothalamus (p<0.01). Similarly, the mRNA levels of KiSS-1, G protein-coupled receptor 54 (GPR54) and GnRH were significantly decreased in hypothalamus (p<0.01) from VCZ-treated group. As expected, the transcriptional activities of luteinizing hormone-${\beta}$ (LH-${\beta}$) and follicle stimulating hormone-${\beta}$ (FSH-${\beta}$) in the anterior pituitary from VCZ-treated group were also significantly lower than those from the control group. The present study indicates that(i) the inhibitory effect of VCZ exposure on the onset of puberty in immature female rats could be derived from the reduced transcriptional activities of gonadotropin subunits and their upstream modulators such as GnRH and KiSS-1 in hypothalamus-pituitary neuroendocrine axis, and (ii) these inhibitory effects could be mediated by NO signaling pathway.

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The Consequences of Mutations in the Reproductive Endocrine System

  • Choi, Donchan
    • Development and Reproduction
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    • v.16 no.4
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    • pp.235-251
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    • 2012
  • The reproductive activity in male mammals is well known to be regulated by the hypothalamus-pituitary-gonad axis. The hypothalamic neurons secreting gonadotropin releasing hormone (GnRH) govern the reproductive neuroendocrine system by integrating all the exogenous information impinging on themselves. The GnRH synthesized and released from the hypothalamus arrives at the anterior pituitary through the portal vessels, provoking the production of the gonadotropins(follicle-stimulating hormone (FSH) and luteinizing hormone (LH)) at the same time. The gonadotropins affect the gonads to promote spermatogenesis and to secret testosterone. Testosterone acts on the GnRH neurons by a feedback loop through the circulatory system, resulting in the balance of all the hormones by regulating reproductive activities. These hormones exert their effects by acting on their own receptors, which are included in the signal transduction pathways as well. Unexpected aberrants are arised during this course of action of each hormone. This review summarizes these abnormal phenomena, including various mutations of molecules and their actions related to the reproductive function.

Elk 사슴에서 발정동기화 인공수정 후 임신율과 발정 탐지기(Magic Doctor)를 이용한 재발정 발현양상 관찰

  • 류재원;지달영;김창근;방명걸;정영채;이장희;윤종택;이호준;이주형
    • Proceedings of the KSAR Conference
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    • 2004.06a
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    • pp.284-284
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    • 2004
  • 본 연구는 Elk 사슴에서 Magic Doctor(한경게놈텍)를 이용하여 발정동기화 인공수정 후 재발정 행동의 발현양상을 관찰하기 위해 실시하였다. 미경산록 7두와 경산록 13두를 공시하였고, 발종동기화 및 인공수정은 번식계절인 9월에 progesterone이 3 g 함유된 controlled intravaginal drug-releasing device(CIDR)를 14일간 질내에 삽입하고 제거한 후에 pregnant mare serum gonadotropin(PMSG) 250IU틀 근육 주사하여 발정동기화와 배란을 유도하였다. 인공수정은 CIDR제거 후 60∼62시간째에 실시하였고 인공수정 후 비임신 개체의 재발정 발현 양상을 관찰하였다. (중략)

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LHRH-a 콜레스테롤 펠렛에 의한 농어의 성숙/배란유도 효과 및 혈중 스테로이드 호르몬의 농도 변화

  • Baek, Hye-Ja;An, Chul-Min;Kim, Kyung-Gil;Myoung, Jung-In;Kim, Yoon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.300-301
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    • 2000
  • 고급단백질의 수요가 증가함에 따라 양식어류개발의 필요성이 가중되면서 유용어종을 대상으로 계획적이고 안정적인 대량종묘를 확보하기 위해서는 인위적으로 성숙/산란을 조절할 수 있는 방법을 개발하는 것이 우선 과제이다. 이러한 방법에는 적합한 호르몬제를 사용하던지 또는 사육 환경조건을 변화시키는 방법 등이 있는데(Donaldson and Hunter, 1983) 호르몬제를 사용할 경우, 자연산란과 비교해볼 때 난질이 좋지않아 수정률 저하를 초래할 경우가 많다. 지금까지 양식현장에서는 HCG(태반선성선자극호르몬)가 널리 사용되어왔으나, 최근에는 GnRH (gonadotropin hormone-releasing hormone)를 이용한 성숙/배란유도가 성행되고 있으며 이에 대한 투여방법도 및 가지로 연구되고 있다 (Okumura and Sakae, 1993; Leu and Chou, 1996). (중략)

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Neuroendocrine System in Seasonal Breeder: Focusing on the Reproductive Activity of Male Golden Hamster

  • Choi, Don-Chan;Lee, Seung-Hoon
    • Development and Reproduction
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    • v.16 no.1
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    • pp.1-8
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    • 2012
  • The reproduction of animals is a way to maintain their species and demands a large amount of energy. The golden hamsters are seasonal breeders whose reproductive activities are regulated by photoperiod (length of day time in a day). The photic information received is transported to the pineal gland via many steps. Melatonin produced by the pineal gland affects the reproductive neuroendocrine system to manage reproductive activities. The major regulator neurons, secreting gonadotropin-releasing hormone, integrate all kinds of information to govern the reproductive frame hypothalamuspituitary-gonad axis. The elements impinging on the neurons are recently outspread. Thus the present review is to briefly survey the elements discovered newly and subjected to the active research realm and their correlations, focusing on the regulation of reproduction in mainly male golden hamsters as a representative animal.

Reproductive Cvcle-related Changes in GnRH Immunoreactivitv in the Brains of Three Congeneric Species of Frog. (3종의 개구리 뇌에서 생식주기에 따른 GnRH 면역반응성의 변화)

  • 임욱빈;김정우
    • The Korean Journal of Zoology
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    • v.37 no.3
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    • pp.311-317
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    • 1994
  • Seasonal variations of GnRH were investigated by immunohlstochemicsl technique in three species of frog, Rona niEromaculutu, R. dvbowskii 8nd R. mgosa with different ovulation period in order to examine the relationship between GnRH expression and reproductive function. In all three species of frog, the intensity of GnRH immunoreactivitv and the number of GnRH neurons in the brawn were relatively high in frogs at the pre-ovulation period and markedly increased at the ovulation period. Those were then decreased after ovulation and further lowered during early hibernation period. These results indicate that GnRH experssion is closely related to specific phases of annual reproductive cycle in frog.

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시상하부 GnRH 뉴런의 신경내분비학적 연구

  • 김경진
    • 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.

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