• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.269-275
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• 1996

Biosynthesis and secretion of anterior pituitary hormones are under the control of specific hypothalamic stimulatory and inhibitory factors. Among them, Growth Hormone Releasing Hormone (GHRH) is the major stimulator of pituitary somatotrophs activating GH gene expression and secretion. Human GHRH is a polypeptide of 44 amino acids initially isolated from pancreatic tumors, and the gene for the hypothalamic form of GHRH is organized into 5 exons spanning over 10 kilobases (kb) on genomic DNA and encodes a messenger RNA of 700-750 nucleotides. Several neuropeptides classically associated with the hypothalamus have been found in the extrahypothalamic regions, suggesting the existence of novel sources, targets and functions. GHRH-like immunoreactivity has been found in several peripheral sites, including placenta, testis, and ovary, indicating that GHRH may also have regulatory roles in peripheral reproductive organs. Furthermore, higher molecular weight forms of the GHRH transcripts were identified from these organs (1.75 kb in testis; 1.75 and >3 kb in ovary). These tissue-specific expression of GHRH gene suggest the existence of unique regulatory mechanism of GHRH expression and function in these organs. In fact, placenta-specific and testis-specific promoters for GHRH transcripts which are located in about 10 kb upstream region of hypothalamic promoter were reported. The use of unique promoters in extrahypothalamic sites could be refered in a different control of GHRH gene and different functions of the translated products in these tissues. Somatotrophs and lactotrophs have been thought to be derived from a common bipotential progenitor, the somatolactotrophs, which give origins to either phenotypes. Although the precise mechanism responsible for the lactotroph differentiation in the anterior pituitary gland has not been yet clalified, there are several candidators for the generation of lactotrophs. In human, the presence of GHRH peptides with different size from authentic hypothalamic form in the normal anterior pituitary and several types of adenoma were demonstrated. Recently our group found the existence of immunoreactive GHRH and its transcript from the normal rat anterior pituitary (gonadotroph> somatotroph> lactotroph), and the GHRH treatment evoked the increased proliferation rate of anterior pituitary cells in vitro. The transgenic mouse models clearly shown that GHRH or NGF overexpression by anterior pituitary cells induced development of pituitary hyperplasia and adenomas particularly GH-oma and prolactinoma. Taken together, we hypothesize that the pituitary GHRH could serve not only as a modulator of hormone secretion but as a paracrine or autocrine regulator of anterior pituitary cell proliferation and differentiation. Interestingly enough, the expression of Pit-1 homeobox gene (the POU class transcription factor) was confined to somatotrophs, lactotrophs and somatolactotrophs in which GHRH receptors are expressed commonly. Concerning the mechanism of somatolactotroph and lactotroph differentiation in the anterior pituitary, we have focused following two possibilities; (1) changes in the relative levels or interactions of both hypothalamic and intrapituitary factors such as dopamine, VIP, somatostatin, NGF and GHRH; (2) alterations of GHRH-GHRH receptor signaling and Pit-1 activity may be the cause of lactotroph differentiation or pituitary hyperplasia and adenoma formation. Extensive further studies will be necessary to solve these complicated questions.

• 한국동물학회지
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• 제39권4호
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• pp.337-351
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• 1996

멜라토닌은 대뇌와 소뇌 사이에 위치한 송과선에서 분비되는 호르몬으로 빛이 없는 밤에만 분비된다. 멜라토닌은 분자적 수준에서부터 개체의 행동에 이르기 까지 다양한 기능을 보인다. 특히, 생식에 미치는 영향은 광범위하여, 온대지방에 사는 대부분의 동물은 주위 환경에 적응하여 종족을 유지하는 유일한 계절적 번식을 한다. 햄스터의 생식활동은 여름에 왕성하고 겨울에 정지된다.이는 많은 환경요소중 광주기의 효과가 송과선에 의해 제거하면 광주기의 영향은 사라진다. 즉 생식에 미치는 광주기의 효과가 송과선에 의해 중재 됨을 의미한다. 또한 송과선 호르몬인 멜라토닌의 적절한 처리는 생식활동을 억제한다. 따라서 멜라토닌은 생식에 미치는 광주기의 정보를 생식내분비계로 전달하는 신경전달물질로 사료된다. 시상하부의 특정부위를 절제한 후 광주기나 멜라토닌을 처리하여 멜라토닌의 작용부위에 관한 연구가 되었으나 동물마다 차이점을 보인다. 대부부의 동물에서 공통적인 부위는 suprachiasmatic nuclei와 pars tuberalis이다. 멜라토닌이 생식에 미치는 작용기작은 아직 밝혀지지 않았다. 이는 멜라토닌의 지속적 처리가 멜라토닌의 장기적처리는 이들 호르몬의 분비를 저하시키고, 시상하부에서의 gonadotropin-releasing hormone (GnRH)양을 증가시킨다. 이 결과는 멜라토닌의 지속적인 처리가 시상하부로부터의 GnRH 양을 분비를 감소킴으로써 생식활동을 억제하는 것으로 사료된다.그러나, 멜라토닌에서 GnRH 신경까지의 정보전달은 아직 밝혀지지 않았다. Opioid 신경에 대한 광주기와 멜라토닌의 효과가 동일한 점은 opioid신경의 매개체 역할을 제시하고 있다. 최근에 멜라토닌 수용체가 개구리의 피부와 몇몇 동물의 뇌와 시세포에서 크로닝되었다. 이수용체는 G protein과 관련되고 cAMP 생성을 억제한다. 앞으로 이 멜라토닌 수용체의 존재여부와 분자생물학적 연구는 멜라토닌의 작용부위와 표적세포에서의 작용기작을 설명하는 데 크게 기여할 것으로 기대된다.

• 환경생물
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• 제20권3호
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• pp.224-231
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• 2002

광주기(하루 중 빛의 길이)는 골든 햄스터의 생식을 조절하는 주된 요인이다. 광주기 정보는 멜라토닌을 통하여 생식 내분비계로 전달된다. 따라서 멜라토닌이 생식에 미치는 효과를 여러 광주기에 노출시킨 햄스터에서 조사하였다. 단주기(하루 중 12시간 이하의 조명)에 노출시킨 동물들과 저녁에 멜라토닌을 주사한 동물들의 정소 무게는 현저하게 줄어들었으나, 장주기 (하루 중 12.5시간 이상의 조명)에 유지된 동물과 오전에 멜라토닌을 투여한 동물들의 정소 무게는 줄어들지 않았다. 퇴화된 정소를 조직학적으로 조사한 결과, 세정관 직경이 감소되었고, 세정관내 세포수가 두드러지게 줄어들었다. 또한 생식 능력이 퇴화된 동물의 혈중 여포자극호르몬과 황체호르몬의 수준도 생식 능력을 보유하고 있는 동물에 비해 뚜렷하게 감소하였다. 멜라토닌 수용체가 역전사 polymerase chain reaction으로 동정되었고 조직특이성 또한 조사하였다. 동정된 멜라토닌 수용체는 309염기였으며, 시상하부와 뇌하수체를 포함하는 다양한 장기에서 발현되었다. 생식을 조절하는 핵심 물질인 gonadotropin releasing hormone (GnRH) 유전자의 발현 또한 동정되었다. 그러나 멜라토닌 처리와 광주기 처리는 GnRH유전자 발현에 영향을 미치지 않았다. 종합하면, 광주기의 효과는 멜리토닌을 경유하여 발휘되며, 멜라토닌은 GnRH유전자의 발현보다는, 생성된 GnRH의 분비에 영향을 미쳐 생식내분비계에 간접적으로 작용함을 알 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• 제36권3호
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• pp.225-230
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• 2009

악성 흑색종의 유병률은 계속 증가하고 있는데, 미국 및 유럽의 역학조사에 따르면, 그 증가율은 매년 3~7% 정도로 보고되고 있다. 여성에서 악성 흑색종의 유병률은 호르몬 치료를 시작하는 폐경전후기에 그 증가율이 가장 높다. 악성 흑색종과 여성 호르몬사이의 관련성에 관한 여러 연구가 있었으나, 아직 그 관계는 불명확한 상태이다. 또한 흑색종 환자에 대한 호르몬 치료의 안전성 역시 입증되지 않은 상태이다. 저자들은 55세부터 지속적 황체호르몬 병합 요법을 통한 에스트로겐 보충요법 및 티볼론 제제로 호르몬 치료를 받은 65세 여성에서 발생한 악성 흑색종 1례를 경험하여, 이를 문헌고찰과 함께 보고하는 바이다.

• Clinical and Experimental Reproductive Medicine
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• 제45권4호
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• pp.183-188
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• 2018

Objective: The purpose of this retrospective study was to evaluate the appropriateness of various follicle-stimulating hormone (FSH) starting doses in expected normal responders based on the nomogram developed by La Marca et al. Methods: A total of 117 first in vitro fertilization cycles performed from 2011 to 2017 were selected. All women were expected normal responders and used a recombinant FSH and flexible gonadotropin-releasing hormone antagonist protocol. The FSH starting dose was empirically determined (150, 225, or 300 IU). The FSH starting dose indicated by La Marca's nomogram was determined using female age and serum $anti-M{\ddot{u}}llerian$ hormone or basal FSH levels. If the administered dose was exactly the same as the proposed dose, the cycle was assigned to the concordant group (34 cycles). If not, it was assigned to the discordant group (83 cycles). Optimal ovarian response was defined as a total of 8-14 oocytes, hypo-response as < 8 oocytes, and hyper-response as > 14 oocytes. Results: Between the concordant and discordant group, ovarian response (optimal, 32.4% vs. 27.7%; hypo-response, 55.9% vs. 54.2%; and hyper-response, 11.8% vs. 18.1%) and the number of total or mature oocytes were similar. Ovarian hyperstimulation syndrome was rare in both groups (0% vs. 1.2%). The implantation rate, clinical pregnancy rate, miscarriage rate, and live birth rate were all similar. Conclusion: The use of the proposed FSH starting dose determined using La Marca's nomogram did not enhance the optimal ovarian response rate or pregnancy rate in expected normal responders. Individualization of the FSH starting dose by La Marca's nomogram appears to have no distinct advantages over empiric choice of the dose in expected normal responders.

• Clinical and Experimental Reproductive Medicine
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• 제51권1호
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• pp.48-56
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• 2024

Objective: This study investigated the relationship of anthropometric and metabolic risk factors with seminal and sex steroidal hormone parameters in a screened population of healthy males. Methods: The participants were healthy young men without chronic or congenital diseases. The body composition parameters that we investigated were measured weight, height, and waist circumference (WC), as well as bioelectrical impedance analysis. Semen samples were analyzed for semen volume, sperm concentration, sperm motility and morphology, seminal pH, and liquefaction time. Biochemistry analysis, including glucose and lipid metabolism parameters, was conducted on fasting blood samples. Testicular volume was calculated separately for each testis using ultrasonography. Results: Body mass index exhibited an inverse association with total sperm count. WC showed negative correlations with numerous seminal parameters, including sperm concentration, total sperm count, sperm morphology, and follicle-stimulating hormone levels. The basal metabolic rate was associated with seminal pH, liquefaction time, and sperm motility. WC, fat mass percentage, and triglyceride levels exhibited negative correlations with sex hormone binding globulin. The measures of glucose metabolism were associated with a greater number of seminal parameters than the measures of cholesterol metabolism. C-reactive protein levels were inversely associated with sperm concentration and total sperm count. Conclusion: Anthropometric and metabolic risk factors were found to predict semen quality and alterations in sex steroidal hormone levels.

• Animal Bioscience
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• 제37권1호
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• pp.50-60
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• 2024

Objective: Testicular fat deposition has been reported to affect animal reproduction. However, the underlying mechanism remains poorly understood. The present study explored whether sperm meiosis and testosterone synthesis contribute to mouse testicular fat deposition-induced reproductive performance. Methods: High fat diet (HFD)-induced obesity CD1 mice (DIO) were used as a testicular fat deposition model. The serum hormone test was performed by agent kit. The quality of sperm was assessed using a Sperm Class Analyzer. Testicular tissue morphology was analyzed by histochemical methods. The expression of spermatocyte marker molecules was monitored by an immuno-fluorescence microscope during meiosis. Analysis of the synthesis of testosterone was performed by real-time polymerase chain reaction and reagent kit. Results: It was found that there was a significant increase in body weight among DIO mice, however, the food intake showed no difference compared to control mice fed a normal diet (CTR). The number of offspring in DIO mice decreased, but there was no significant difference from the CTR group. The levels of follicle-stimulating hormone were lower in DIO mice and their luteinizing hormone levels were similar. The results showed a remarkable decrease in sperm density and motility among DIO mice. We also found that fat accumulation affected the meiosis process, mainly reflected in the cross-exchange of homologous chromosomes. In addition, overweight increased fat deposition in the testis and reduced the expression of testosterone synthesis-related enzymes, thereby affecting the synthesis and secretion of testosterone by testicular Leydig cells. Conclusion: Fat accumulation in the testes causes testicular cell dysfunction, which affects testosterone hormone synthesis and ultimately affects sperm formation.

• Clinical and Experimental Reproductive Medicine
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• 제6권1_2호
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• pp.23-28
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• 1979

To determine whether hormone analysis of amniotic fluid could be used for accurate determination of fetal sex, we measured testosterone(T) and follicle-stimulating hormone in 19 amniotic fluid samples. The mean T in amniotic fluid of 8 women earring male fetuses was 310 pg. per milliliter and of 11 women earring female fetuses was 150 pg. per milliliter (P<0.05${\ast}$). The mean amniotic fluid FSH of 1.16 mI.U. per milliliter for 7 women with male fetuses was over trifold lower than that for subjects with female fetuses. The mean amniotic fluid FSH of female fetuses was 3.85 mI.U. per milliliter (P<0.01${\ast}$) Measurement of T & FSH in amniotic fluid may be an adjunct method for fetal sex determination.

• 생물환경조절학회지
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• 제13권1호
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• pp.56-60
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• 2004

진딧물 포식성 무당벌레의 성충을 대상으로 저온처리에 의한 생식적 휴면을 유도하였다. 성충의 인위적인 생식적 휴면의 유지는 $4^{\circ}C$에서 5개월 정도까지 가능하며 먹이의 공급이 필요하지 않아 경제적인 무당벌레의 저장법이라 할 수 있다. 하절기를 포함한 계절에 구분 없이 무당벌레의 성충의 저온저장이 가능하여 필요시 어느 때라도 진딧물 발생지에 무당벌레를 공급할 수 있게 되었다. 휴면 후 $25^{\circ}C$에서 수명과 산란력이 우수하며 생식호르몬인 juvenile hormone(JH)의 합성 유사체인 methoprene은 암컷의 초반기 생식력을 증진시키는 효과를 나타낸다.

• 농업과학연구
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• 제46권2호
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• pp.303-313
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• 2019

Twenty crossbred (Yorkshire ${\times}$ Landrace) gestating sows were used to determine the effects of Moringa Oleifera leaf (MOL) supplementation in lactating sow diets with or without banana peel powder (BPP) on reproductive performance, fecal moisture content, rectal temperature and hormone profile. The treatments were as follows: 1) CON (control diet), 2) M1 (control diet + 0.5% MOL), 3) M2 (control diet + 1.0% MOL), 4) M3 (control diet + 0.75% MOL and 0.75% BPP), and 5) M4 (control diet + 1.5% MOL and 1.5% BPP). The diets was fed from da 107 of gestation to weaning. MOL and BPP supplementation decreased (p < 0.05) the fecal moisture content compared with that of the CON at day 0 and 7 after farrowing, and 1.0% supplementation of MOL also decreased (p < 0.05) the fecal moisture content at day 14 after farrowing. On farrowing day, MOL supplementation decreased (p < 0.05) the blood cortisol and norepinephrine concentrations compared with the CON. In conclusion, the results of this study show that MOL supplementation decreased the fecal moisture content and plasma concentrations of cortisol and norepinephrine, and MOL and BPP supplementation also decreased the fecal moisture content in lactating sows.