• 한국발생생물학회지:발생과생식
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• 제26권2호
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• pp.37-47
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• 2022

Photoperiod has well been established to regulate testicular activities in golden hamsters. These animals breed actively around summer but become infertile in winter. In males, testicles are full of multistep germ cells including spermatozoa in summer. But in winter only fundamental cells consisting of the testicles are detected. The testicular degeneration is accompanied by the reduced levels of blood gonadotropins and testosterone. In this study, the expressions of gonadotropin subunit genes were investigated in the reproductive active and inactive testicles. And parts of sequences of the gonadotropin subunits were identified and compared with those of other rodents. As results, common gonadotropin alpha (CGa), follicle-stimulating hormone (FSH) β, and luteinizing hormone (LH) β genes were equivalently detected in pituitaries of both sexually active and inactive animals. In considering low concentrations of gonadotropin hormones determined in pituitary, the present findings imply that the processes involved in translation and/or formation of functional hormones could be impeded in the sexually inactive hamsters. All the nucleotide sequences of gonadotropin subunits identified in this study were same as those reported previously except for one base in CGa. An unsure amino acid deduced from the CGa sequence was confirmed from mRNA sequencing. The outcomes mentioned above suggest that animals with regressed testes prepare for the sexually active period forthcoming in the future.

• Clinical and Experimental Reproductive Medicine
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• 제36권3호
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• pp.219-224
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• 2009

목 적: 저성선자극호르몬 성선저하증은 남성불임의 흔치 않은 원인이다. 저자들은 성선자극호르몬 특히 인간융 모성선자극호르몬 (Human chorioinc gonadotropin: hCG)/인간폐경성선자극호르몬 (Human menopausal gonadotropin: hMG) 치료가 정자형성 및 임신에 미치는 영향에 대해 알아보았다. 연구방법: 2001년 11월부터 2007년 3월까지 불임을 주소로 내원하여 저성선자극호르몬 성선저하증으로 진단되어 성선자극호르몬 (hCG/hMG) 치료를 받은 10명의 진료 기록을 후향적으로 분석하였다. 치료 후 임신 여부를 알아보았으며, 치료 전 고환의 용적에 따라 10 cc 미만인 군 (n=4)과 10 cc 이상인 군 (n=6)으로 나누어 치료 전후의 정액지표와 혈중 FSH, LH 및 testosterone 등의 호르몬 검사를 시행하여 비교하였다. 결 과: 10명의 환자 중 7명 (70%)에서 임신에 성공하였으며 치료 후 혈중 FSH, testosterone 수치가 의미있게 증가하였다. 고환 용적이 큰 군에서 치료 후 정액량, 정자수, 운동성 및 testosterone이 유의하게 증가하였다. 결 론: 불임을 주소로 온 환자에게 흔치는 않지만 면밀한 검사를 통해 저성선자극호르몬 성선저하증을 진단할 수 있어야 하며, hCG/hMG 병합요법은 자연임신 뿐만 아니라 최근의 보조생식술과 연계하여 충분히 성공적인 치료에 도달할 수 있다.

• 대한약리학회지
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• 제23권2호
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• pp.57-75
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• 1987

Two modalities of gonadotropin secretion, pulsatile gonadotropin and preovulatory gonadotropin surge, have been identified in the mammals. Pulsatile gonadotropin secretion is modulated by the pulsatile pattern of GnRH release and complex ovarian steroid feedback actions. The neural mechansim that regulates the pulsatile release of GnRH in the hypothalamus is called "GnRH pulse generator". Ovarian steroids, estradiol and progesterone, appear to exert thier feedback effects both directly on the pituitary to modulate gonadotropin release and on a hypothalamic site to modulate GnRH release; estradiol primarily affects the amplitude while progesterone decreases the frequency of the pulsatile GnRH. Steroid hormones are known to affect catecholamine transmission in brain. MBH-POA is richly innervated by NE systems and close apposition of NE terminals and GnRH cell bodies occurs in the MBH as well as in the POA. NE normally facilitates pulsatile LH release by acting through ${\alpha}-receptor$ mechanism. However, precise nature of facilitative role of NE transmission in maintaining pulsatile LH has not been clearly understood. Close apposition of DA and GnRH terminals in ME might permit DA to influence GnRH release. Action of DA transmission probably is mediated by axo-axonic contacts between GnRH and DA fibers in the ME. Dopamine transmission does not normally regulate pulsatile LH release, but under certain conditions, increased DA transmission inhibit LH pulse. Endogenous opioid acts to suppress the secretion of GnRH into hypophysial portal circulation, thereby inhibiting gonadotropin secretion. However, an interaction between endogenenous opioid peptides and gonadotropin release is a complex one which involves ovarian hormones as well. LH secretion appears to be most suppressed by endogenenous opioids during the luteal phase, at a time of elevated progesterone secretion. The arcuate nucleus contains not only cell bodies for GnRH and ${\beta}-endorphin$ but also a dense aborization of fibers suggesting that GnRH release is changed by the interactions between GnRH and ${\beta}-endorphin$ cell bodies within the arcuate nucleus. The frequency and amplitude of pulsatile LH release seem to be increased during the preovulatory gonadotropin surge. Estradiol exerts positive feedback action on the hypothalamo-pituitary axis to trigger preovulatory LH surge. GnRH is also crucial hormonal stimulus for preovulatory LH surge. It is unlikely, however, that increased secretion of GnRH during the preovulatory gonadotropin surge represents an obligatory neural signal for generation of the LH discharge in primates including human. Modulation of preovulatory LH surge by catecholamines has been studied almost exclusively in rats. NE and E may be involved in distinct way to accumulate GnRH in the MBH and its release into the hypophysial portal system during the critical period for LH surge on proestrus in rats. However, the mechanisms whereby augmented adrenergic transmission may facilitate the formation and accumulation of GnRH in the ME-ARC nerve terminals before the LH surge have not been clearly understood.

• 한국발생생물학회지:발생과생식
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• 제28권1호
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• pp.1-12
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• 2024

Gonadotropin-releasing hormone (GnRH), a critical hormone produced in the hypothalamus, is essential for regulating reproductive processes. It has also been demonstrated the presence of GnRH and its receptors (GnRHR) in ovarian and uterine tissues, but little was known about the regulation mechanism of their expression in these organs and ovarian aging. Therefore, the aim of this study was to investigate the expression of GnRHR in the ovary and uterus of mice, particularly after high-dose gonadotropin treatments and in relation to aging. Quantitative real-time-PCR (qRT-PCR) revealed that pituitary gland had the highest GnRHR expression in both young and aged mice. In addition, liver expression was higher in young mice, whereas thymus expression was higher in aged mice. GnRHR mRNA was present in the ovaries of both young and aged mice but nearly undetectable in the uterus of aged mice. We next examined the expression of GnRHR in the ovary and uterus in response to high-dose administration of pregnant mare serum gonadotropin (PMSG). After PMSG administration, GnRH mRNA levels were significantly decreased in the ovary but increased in the uterus. The expression of GnRH mRNA in these organs showed opposite trends to that of GnRHR expression. These results suggest the involvement of GnRH in age-related reproductive decline and the potential effects of high-dose gonadotropin treatments on reproductive organ function.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 춘계 수산관련학회 공둥학술발표회
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• pp.427-428
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• 2002

• 한국양식학회:학술대회논문집
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• 한국양식학회 2002년도 춘계 한국양식학회 학술대회 발표요지
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• pp.230.2-231
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• 2002

• Clinical and Experimental Pediatrics
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• 제53권3호
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• pp.294-299
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• 2010

Although the increasing incidence of central precocious puberty (CPP) in Korea has recently raised public concerns about health and growth problems, there are many areas of uncertainty regarding the pathogenesis, diagnosis, and management of CPP. In this paper, we review the definition of precocity, the assessment of CPP, and the hormonal abnormalities that support the diagnosis. In addition, we review the practical guidelines regarding the clinical use of gonadotropin-releasing hormone analogs in children with CPP. Indications for treatment, determination of dosage, monitoring during treatment, and discontinuation of therapy are discussed.

• Clinical and Experimental Reproductive Medicine
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• 제28권1호
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• pp.73-77
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• 2001

Objective: To report the pregnancy which was made by in vitro fertilization using recombinant follicle stimulating hormone and gonadotropin releasing hormone antagonist. Material and Method: Case report. Results: Six oocytes were retrieved and all were fertilized by intracytoplasmic sperm injection. Six embryos were transferred and the pregnancy was confirmed. Conclusion: It is envisaged that the availability of recombinant gonadotropins and gonadotropin releasing hormone antagonists will ultimately lead to shorter, cheaper and safer treatments, using reduced dosages.

• Asian-Australasian Journal of Animal Sciences
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• 제4권1호
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• pp.1-5
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• 1991

Responsiveness of the testis to pregnant mare's serum gonadotropin (PMSG) was studied in immature Nili-Ravi buffalo bulls. Four month old bull calves weighing between 66 to 100 kg raised under uniform condition, were treated with 1000 IU PMSG or vehicle, daily, for six days. PMSG induced an increase in the size of the testis, enlargement of the seminiferous tubules and activation of the spermatogonia. The number of differentiated Leydig cells in the testis of gonadotropin treated animals increased considerably over that of the control testes. A significant increase in plasma testosterone concentrations was observed 24 h following the first injection of PMSG and the levels continued to increase until day 6. In vehicle treated animals plasma testosterone levels remained more or less at pretreatment values. The data suggest that buffalo bull testis is functionally responsive to gonadotropin at an early stage of prepubertal development.

• Clinical and Experimental Reproductive Medicine
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• 제14권2호
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• pp.119-126
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• 1987

Exponential rise rate(ERR) of serum estradiol concentrations during active follicular phase was calculated for 49 ovulation induction cycles by human menopausal gonadotropin to know the ovulation induction outcome according to ERR classified into 3 groups with low, moderate and high ERR values(Group I${\leqq}$0.3, 0.3${\leqq}$0.6，Group III>0.6). The results were summarised as follows : 1. No significant difference in the dosage of human menopausal gonadotropin was identified in each group. 2. The mean serum estradiol concentration at the day of human chorionic gonadotropin injection in Group II and Group ill was significantly higher than that in Group I . 3. The mean diameter of leading follicles at the day of human chorionic gonadotropin injection showed no significant difference in each group. 4. No significant difference in the ovulation rate was observed in relation to ERR. How ever, 20% and 20.8% of pregnancy rate in Group I and Group II were achieved while no pregnancy was occurred in Group III. 5. The ovarian hyperstimulation frequency was significantly higher in Group ill that in Group I and Group II. In conclusion, the study suggests that exponential rise rate of serum estradiol is a useful tool in HMG ovulation induction by preventing ovarian hyperstimulation without reducing pregnancy success rate.