• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.40.2-41
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• 1999

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.161.1-161
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• 2003

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.174.2-174
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• 1999

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.174.1-174
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• 1999

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 2001.04a
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• pp.69.2-69
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• 2001

No Abstract, See Full Text

• Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.37-43
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• 2000

We used a mammalian GnRH antagonist, $[Ac-3,4-dehydro-Pro^1,\;D-p-F-Phe^2,\;D-Trp^{3.6}]$-GnRH, to examine the details of the salmon type gonadotropin-releasing hormone (sGnRH) and GnRH agonist analog $(Des-Gly^{10}$[d-Ala^6]-ethylamide GnRH; GnRHa) functions in the control of maturational gonadotropin (GTH II) secretion, in precocious male rainbow trout, in both in vivo and in vitro experiments. In the in vivo study, plasma GTH II levels increased by sGnRH or GnRHa treatment, but the response was more rapid and stronger in the GnRHa treatment group. The increase in GTH II was significantly suppressed by the GnRH antagonist, while the antagonist had no effect on basal GTH II levels in both groups. The GnRH antagonist showed stronger suppression of GTH II levels in the sGnRH treatment fish than in the GnRHa treatment fish. In addition, plasma androgenic steroid hormones (testosterone and 11-ketotestosterone) increased by the sGnRH or GnRHa treatment. The GnRH antagonist significantly inhibited the increases in plasma androgenic steroid hormone levels stimulated by the sGnRH or GnRHa, while the antagonist had no effect on basal androgenic steroid hormone levels in both groups. In the in vitro study, treatment with sGnRH or GnRHa increased GTH II release from the cultured dispersed pituitary cells, but the response was stronger in the GnRHa treatment group. The increase in GTH II release by GnRH was suppressed by adding the GnRH antagonist, dose­dependently. On the other hand, basal release of GTH II did not decrease by the GnRH antagonist treatment in both groups. These results suggest that the GnRH antagonist, $[Ac-3,4-dehydro-Pro^1,\;D-p-F-Phe^2,\;D-Trp^{3.6}]-GnRH$, used in this study is effective in blocking the action of GnRH-induced GTH II release from the pituitary gland both in vivo and in vitro.

• The Korean Journal of Zoology
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• v.39 no.4
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• pp.337-351
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• 1996

Melatonin Is a multifunctional hormone secreted from the pineal gland in the middle of cerebrum and cerebellum. Its synthesis and release reflect photopedod;Photopedod is a yearly predictable ambient factor that most animals utilize as an environmental cue for maximum survival. Hamsters maintaln reproductive activity in summer during which day length exceeds night time. Upon the advent of autumnal equinox they undergo gonadal regression. The photoperiodic effects are prevented by removal of the pineal gland and restored by the timed repiacument of melatonin. The results suggest that melatonin constitutes part of control mechanism whereby environmental information is transduced to neuroendocrine signal responsIble for the functional integrity of the reproductive system. From the studies for the action site of melatonin following the treatment of photopedod or melatonin in the lesion of a spedflc portion of hypothalamus, suprachiasmatic nuclei and pars tuberalis are shown to be a consensus site for melatonIn. The action of melatonin. In the regulation of reproduction is largely unknown. It is mainly due to the lack of acute effect of melatonin on gonadotropin secretion. However, reduction of the gonadotropln release and augmentation of the hypothalamic gonadotropin-releasing hormone (GnRH) content by long-term treatment of melatonln Indicate that constant presence of melatonln may partidpate in the regulation of sexual activity via the GnRH neuronal system. The action mechanism by which melatonin exerts Its effect on GnRH neuron needs to be eluddated. The inability of opiold analogues to affect the reproductive hormones in sexually regressed animals by inhibftory photopedod and melatonin suggests that the opioldergic neuron may be a prime intervening mediator. Recent cloning of melatonin receptor will contribute to investigate its anatomical Identification and the action mechanism of melatonin on target tissues at the molecular level.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.239-244
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• 2010

Objective: The objective of this retrospective study was to compare the in vitro fertilization (IVF) outcomes of gonadotropinreleasing hormone (GnRH) agonist and GnRH antagonist protocols in poor responders. Methods: A total of 172 cycles in subjects with less than 5 oocytes retrieved treated with either GnRH agonist long protocols or antagonist protocols were included. The outcome variables such as numbers of growing follicles and retrieved oocytes, and the fertilization rate were evaluated as the main outcome measures. Results: There was no difference in regard to the numbers of growing follicles and oocytes, and fertilization rate between the two groups. $E_2$ level on Day 7/8, mean gonadotropin dose, and the days of stimulation were shown to be statistically different (p<0.01, respectively). Conclusion: Considering that similar results were observed with less time and gonadotropin dose, GnRH antagonist protocol may be considered as a preferable choice over GnRH agonist protocols in poor responders.

• Journal of Breast Disease
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• v.6 no.2
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• pp.46-51
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• 2018

Purpose: Endocrine therapy is the preferred treatment for hormone receptor (HR)-positive metastatic breast cancer (MBC). We investigated the efficacy of combined aromatase inhibitor (AI) and luteinizing hormone-releasing hormone (LHRH) agonist in premenopausal patients with HR-positive MBC. Methods: We retrospectively analyzed the medical records of 21 HR-positive premenopausal MBC patients treated with combined AI and LHRH agonist therapy. Results: The median follow-up period was 32.9 months. The overall response rate was 47.6%, with three complete responses (14.3%) and seven partial responses (33.3%). Nine patients (42.9%) achieved stable disease lasting more than 6 months; thus, the clinical benefit rate was 90.4%. The median time to progression was 45.4 months. No patients experienced grade 3 or 4 toxicity. Conclusion: Combined AI and LHRH agonist treatment safely and effectively induced remission or prolonged disease stabilization, suggesting that this could be a promising treatment option for HR-positive premenopausal patients with MBC.

• Clinical and Experimental Reproductive Medicine
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• v.19 no.2
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• pp.175-179
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• 1992

The factors involved in the initial neoplastic transformation and subsquent growth of uterine fibroid are poorly understood. The reduction in uterine fibroid volume associated with the chronic administration of the mechanisms mediating the decrease in fibroid volume in GnRH-a treated patients are poorly defined. The purpose of this study was to determine the proliferating cell nuclear antigen(PCNA) in fibroid from-women pretreated with GnRH analogue(GnRH-a) compared with controls. Tissue was obtained from 16 premenopausal women with uterine fibroid who received GnRH-a(D-Trp6-GnRH) intramusculary every 28 days for four injections. The mean proliferating index(PI) in patients with uterine fibroids was $2.25{\pm}0.9$, and in controls was $8.82{\pm}1.8$(P<0.001). The proliferating index was not corrleated with the reduction of fibroid volume. In this clinical study, although hypoestrogenism may be the main factor that reduce the volume of fibroid, other factors are also considered to be involved in that process. And the regrowth of uterine fibroid may be affected by increased production of PCNA after stopping GnRH-a.