• Clinical and Experimental Reproductive Medicine
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• v.7 no.1_2
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• pp.3-10
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• 1980

Pituitary gonadotropes, as target cells, exhibit cyclic changes in terms of LH and FSH release in synchrony with the estradiol levels. The ultimate release is determined by the relative size of the two pools of gonadotropins, which is regulated by the two controllers: LH-RH and estradiol. LH-RH appears to serve as a primary drive on the gonadotrope, stimulating gonadotropin synthesis, storage, and release. Estradiol amplifies the action of LH-RH and induces the development of a self-priming effect of LH-RH except that it impedes LH-RH mediated gonadotropin release. Negative and positive feedback action of estradiol is revealed to operate by different mechanisms. The pituitary capacity increases severalfold from early to late follicular phase, which is considered to be prerequisite for the development of mid-cycle surge. CNS-hypothalamic dopamine, norepinephrine, and prostaglandins, as well as LH-RH, are involved in the negative and positive feedback effects of estradiol. The possible mechanisms in the triggering of LH-RH release for the initiation of midcycle LH-RH surge are considered.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.29-44
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• 1990

In 105 patients with the past history of poor response to the previous controlled ovarian hyperstimulation(COH) due to poor follicular growth or premature LH surge, the effectiveness of pituitary suppression with gonadotropin-releasing hormone agonist(GnRH agonist) in IVF/GIFT program was evaluated in 112 cycles of COH using a combination regimen of Leuprolide acetate (Lupron TAP Pharmaceuticals, USA) and FSH/hMG or pure FSH from May to December, 1989 at SNUH. Starting on day 21 of the menstrual cycle(MCD #21, Day 1), Lupron (1.0mg/day, subcutaneous) was administered once a day till next MCD #3(suppression phase). After the confirmation of pituitary suppression, ovarian follicular growth was stimulated with FSH/hMG or pure FSH from MCD #3(Day + 1), and Lupron was continued with hMG or FSH until hCG administration (D 0) (stimulation phase). After suppression phase, serum E2 level decreased from 183.7${\pm}$95.1(Day 1) to 17.4${\pm}$12.3pg/ml (Day +1), and serum progesterone level from 19.17${\pm}$8.67 to 0.12${\pm}$0.05ng/ml. But there was no decresas in serum LH and FSH levels; LH from 12.74${\pm}$6.21 to 15.49${\pm}$4.93mIU/ml,FSH from 7.60${\pm}$3.84 to 8.58${\pm}$3.15 rnlU/ml. There was no occurrence of premature LH surge during COH. Eleven cycles(9.8%) were cancelled due to poor follicular growth during stimulation phase, and 3 cycles (3.0%) failed in the transvaginal oocytes fretrieval. Serum E2 level was 1366.8${\pm}$642.4 on D 0 and 1492.3${\pm}$906.9pg/ml on D+1. 7.00${\pm}$3.32 follicles(FD${\geq}$12mm) were observed on D 0, and 6.11${\pm}$4.15 oocytes were retrieved, with the oocyte retrieval rate per follicle of 95.0%. 3.59${\pm}$2.57 oocytes were fertilized and cleaved with the oocyte cleavage rate of 55.7%. In 83 IVF patients, 4.08${\pm}$2.39 embryos were transferred, and 16 pregnancies were obtained with the pregnancy rate per ET 2.39 mebryos were transferred, and 16 pregnancies were obtained with the pregnancy rate per ET of 19.3%. In 6 GIFT patients, 7.83${\pm}$3.31 oocytes were retrieved and transferred with maximum number of 6, but no pregnancy was obtained. When compared with the previous 108 cycles of COH using FSH/hMG or pure FSH regimen, the cancellation rate during COH was significantly decreased, and all the parameters of the outcome of COH including the pregnancy rate were increased. These data suggest that GnRH agonist therapy for pituitary suppression is an effective adjunct to the current gonadotropin regimens for COH in IVF/GIFT and can increase the probability of oocytes retrieval and pregnancy, especially in the previous poor responders.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.93-102
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• 1998

Normal and abnormal follicular growth and steroidogenesis depend on gonadotropins as well as intraovarian peptides, which may mediate or potentiate gonadotropin action. Inhibin also affect follicular development and steroidogenesis and may play a role in dominant follicle selection and follicular atresia. Therefore, we studied the differences of serum inhibin, gonadotropin and androgen levels in the women with only the ultrasound findings and no disorder, and polycystic ovary (PCO) with ovulatory disturbance. We prospectively analysed forty-three women with PCO. The diagnosis of PCO was based on typical appearance of the ovaries on TVS. Twelve women with regular menstrual cycle and normal ovarian morphology were selected as control. Basal levels of inhibin, luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol $(E_2)$, testosterone (T), androstenedione (ADD), dehydroepiandrosterone-sulfate (DS), prolactin and TSH in serum were determined. There were significant differences in basal LH levels and LH/FSH ratio between the control and the women with PCO. The basal levels of inhibin and $E_2$ in the oligo-amenorrheic PCO (N=34) were significantly higher than those in the control. There was higher negative correlation between the inhibin and T levels in the oligo-amenorrheic PCO, but, not in the regular cycling PCO. Also, there was higher positive correlation between the LH and T levels in the oligo-amenorrheic PCO, but not in the regular cycling PCO. These data presume that the initial event of PCO is elevated pituitary LH secretion. Elevated levels of LH may down-regulate LH receptors on granulosa cells and also cause hypertrophy of the thecal layer. High level of androgen secreted by the hypertrophied thecal layer may stimulate inhibin secretion from granulosa cells and can be converted to estrogen by extraovarian tissues and could serve to augment pituitary sensitivity to GnRH with a resultant secretion of more LH than FSH. Inhibin may inhibit FSH action on granulosa cell in the PCO follicle, impairing follicular development and dominant follicle selection resulted in ovulatory disturbance.

• 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.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.1
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• pp.135-141
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• 1997

The early studies demonstrated that the relative amount of FSH was important for stimulating normal ovarian activity and demonstrated the existence of a threshold level for FSH, above which follicular growth was activated. It was found that only a modest increase in circulating FSH level above the threshold (between 10 and 30%) was required to stimulate folliculogenesis. In addition, FSH is primary responsible for initiating estradiol production through the activation of the aromatase enzyme system in granulosa cells, follicular secretion and growth. LH on the other hand, plays a supportive role in ovarian steroidogenesis, stimulating the ovarian thecal cells to produce androgen, the precursor for estradiol synthesis. But there is now an increasing number of reports in the literature demonstrating an adverse effect of LH on fertility and miscarriage in infertile and fertile women. So HP-FSH is the drug of a highly purified FSH preparation which has a higher specific activity and far fewer impurities than FSH. This study was performed to evaluate the efficacy and safety of HP-FSH administered (SC; subcutaneous) versus FSH(IM; intramuscular) for ovulation induction. 20 candidates patients for ovulation induction were participated. All patients underwent pituitary desensitizing with a long gonadotropin-releasing hormone (GnRH) agonist protocol and ovulation induction was started with HP-FSH SC (10 patients; group I) or FSH IM (10 patients; group II). After ovulation, outcome of ovulation induction and local reaction of injection site were compared. There were no difference of outcome of ovulation in two groups except pregnancy rate/embryo transfer. Group I had a higher pregnancy rate/ embryo transfer than Group II (44.4% Vs 28.6%). Pain, redness, tenderness, bruising and itching when the injection received on the first 5 days of treated (50 SC and 50 IM injections) were assessed. There were no significant difference (P>0.05) in the incidence of tenderness, bruising and itching between the IM and SC injection. But IM injection (FSH) had a tendency of higher above incidence. The number of reports of pain, redness were significantly increased in IM injection group (P<0.05). These results indicate that SC administration of HP-FSH has been shown to be as effect for superovulation as traditional gonadotropins, with an improved safety profile due to the removal of extaneous proteins.

• 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.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.503-509
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• 2007

The purpose of this study was to investigate the effect of Gi exercises and soybean milk supplement on the body composition and the physiological parameters including blood level of lipids and related hormones in middle-aged women. The Gi exercise program was composed of warming-up(10 min), main exercise(40 min) and cooling-down(10 min). The 40 middle-aged women between 40 and 60 years old were divided into four groups; the control group(12 women), the Gi exercise group(14 women), the soybean milk supplement group(11 women), and the Gi exercise group with soybean milk supplement(14 women). The Gi exercise program was applied three times a week and two packs of the soybean milk per day were given. The result of this study was as follows 1. The control group showed the increase of body weight, percent body fat, and fat mass than other groups. 2. The blood level of T-C was increased in the control group and the Gi exercise group and exercise with supplemented group were decreased 3. The blood level of HDL-C was significantly decreased in the control group than other groups. 4. The blood level of LDL-C was significantly increased in the control group than other groups. 5. The level of TG were not significantly changed in all groups 6. The follicular stimulating hormone (FSH) and luteinizing hormone (LH) hormone levels were not significantly changed in all study groups

• Development and Reproduction
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• v.11 no.1
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• pp.49-54
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a toxin which specifically kills Leydig cells(LC), has been widely used to prepare the reversible testosterone(T) depletion rat model. In the present study, we monitored the gene expression profiles of pituitary gonadotropins, LH and FSH, up to 7 weeks after EDS injection. Adult male Sprague-Dawley rats($300{\sim}350\;g$ B.W.) were injected with a single dose of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. Total RNAs were purified from each pituitary, and the message levels of common alpha subunit($C{\alpha}$) of pituitary glycoprotein hormones, LH beta subunit($LH{\beta}$), FSH beta subunit($FSH{\beta}$) and GnRH receptor(GnRH-R) were evaluated by semi-quantitative RT-PCRs. The message levels of $C{\alpha}$ increased sharply during weeks 1-4, then return to the control level on week 5. The mRNA levels of $LH{\beta}$ were elevated after week 2, reached the peak at week 4, then declined to the control level after week 5. The message levels of $FSH{\beta}$ were elevated after week 2, reached the peak at week 3, then declined to the nadir at week 5. Similarly, the mRNA levels of GnRH-R were elevated after week 2, reached the peak at week 3, then gradually declined to the control level after week 5. The present study indicated that EDS treatment could induce reversible alterations in the transcriptional activities of gonadotropin subunits and GnRH-R in the anterior pituitary from male rats. EDS injection model might be useful to understand the mechanism of hormonal regulation of hypothalamus- pituitary neuroendocrine axis in male rats.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.10-12
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.357-364
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.