• Journal of Embryo Transfer
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• v.25 no.4
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• pp.287-290
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• 2010

On January 6, 2010, two months earlier than normal breeding season, a red fox vixen was implanted with synthetic GnRH analogue, Deslorelin. Blood was sampled every 2~3 days from the day of implant to identifying spermatozoa on stains of epithelial cells. Estradiol and progesterone were examined. Even though the vixen was in non-breeding season, she was mated by a male fox. Pregnancy was confirmed by canine pregnancy detection kit that detect relaxin released from placenta. Four healthy pups were born on March 9, 2010. This is the first report showing synthetic GnRH can activate ovarian function and lead to fertile estrus of red fox in non-breeding season.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.121-124
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• 2007

Freshwater-adapted maturing chum salmon (Oncorhynchus keta) involuntarily captured by stationary nets in Yang-yang seashore areas were transferred to freshwater in an outdoor raceway tank at Yeongdong Inland Fisheries Research Institute, NFRDI, Yang-yang, Gangwon, Korea and kept over 1 day until the start of the experiments. The freshwater-adapted females were single-injected intraperitoneally with gonadotropin-releasing hormone analogue, (GnRH-a: $70\;{\mu}g/kg$ body weight, BW) alone or combined with a dopamine receptor antagonist, pimozide($700\;{\mu}g/kg$ BW). Although gonadosomatic indices [GSI, (gonad weight/BW)${\times}100$] did not show significant changes in both 2004 and 2005, GSI of GnRH-a-injected fish during the 2005 trial slightly increased on the 5th and 7th days post-injection compared to those of vehicle treated fish. Hepatosomatic indices [HSI, (liver weight/BW)${\times}100$] of fish injected with GnRH-a alone and combined with pimozide decreased significantly on the 7th day post-injection in 2004(P<0.05). In 2005 trials, HSI was significantly reduced in GnRH-a treated fish on the 7th day post-injection (P<0.05). Pimozide-injected fish showed a pattern with increase of GSI and decrease of HSI, without significant differences. Taken together, these results suggest that at least in part hypothalamic hormones and dopamine receptor antagonist may induce sexual maturation in freshwater-adapted maturing chum salmon. It remains to evaluate these preliminary results by further researches.

• 대한생식의학회:학술대회논문집
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• 2002.05a
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• pp.65-66
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• 2002

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.100-101
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• 2003

• Clinical and Experimental Reproductive Medicine
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• v.19 no.1
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• pp.81-85
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• 1992

The effects of pulsatile GnRH therapy have been studied for the treatment of different forms of hypogonadotropic hypogonadism, including idiopathic hypogonadotropic hypogonadism and hypogonadism developed as a result of treatment with combination of surgery and irradiation for pituitary or hypothalamic tumor. GnRH was administered subcutaneously in a dose of $10{\mu}g$ every 2 hours with the pulsatile infusion pump. With GnRH therapy, all patients improved secretion of LH, FSH and testosterone. Testicular volumes increased. Spermatogenesis was induced in 8 patients. Pulsatile GnRH therapy is an effective treatment for idiopathic hypogonadotropic hypogonadism and can have a role in hypogonadism previously treated with combination of surgery and irradiation for pituitary or hypothalamic tumor.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1211-1216
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• 2011

Sexual maturity in poultry is controlled by a complex neural circuit located in the basal forebrain, which integrates the central and peripheral signals to activate hypothalamic gonadotrophin-releasing hormone (GnRH) secretion. This study demonstrated the changes of GnRH-I, POMC and NPY mRNA transcription in hypothalamus and IGF-I and leptin levels in serum of Shaoxing ducks during puberty. Body weight increased progressively from d30 to d120 and at d120 the flock reached 5% of laying rate. A significant upregulation of hypothalamic GnRH-I mRNA expression was observed from d60, reaching the peak at d120. POMC and NPY mRNA expression in hypothalamus showed a similar pattern, which increased from d30 to d60, followed by a significant decrease towards sexual maturity. Serum IGF-I levels exhibited two peaks at d30 and d120, respectively. Serum leptin displayed a single peak at d90. The results indicate that the down-regulation of POMC and NPY genes in hypothalamus coincides with the up-regulation of GnRH-I gene to initiate sexual maturation in ducks. In addition, peripheral IGF-I and leptin may relay the peripheral metabolic status to the central system and contribute to the initiation of the reproductive function in ducks.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.75-75
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• 2002

한우의 사육규모가 다두화 된 농가에서 전년도 발정제어 처리에 따라 수태한 임신우의 분만내역과 차기번식에 미치는 영향을 규명하고자 수행하였다. 1. 발정유기방법별 계절번식처리우의 분만율은 PGF₂α구에서 73%(73/100), PRID 구에서 73.3%(22/30), CIDR 구에서 76.6%(23/30), GnRH-PGF₂α-GnRH 처리구에서 81%(81/100)였으며 전체적으로 76.5%(199/260)로 나타났다. 2. 계절번식농가의 자연발정 수정구에서 암송아지는 23.9㎏, 수송아지는 26.2㎏인 반면에 발정유기구에서는 암송아지는 24㎏, 수송아지는 24.9㎏로써 생시체중에 거의 차이를 보이지 않았고, 4개월령 체중에서 자연발정 수정구에서 암송아지 72㎏, 수송아지 75㎏인 반면에 발정유기구에서는 암송아지 75.6㎏, 수송아지 78.3㎏으로 발육상에 특별한 차이가 나타나지 않았다. 3. 다두사육농가의 자연발정 수정구에서 송아지 육성율은 86.5%(251/290)이였으며, 발정제어처리구에서는 87.0%(175/201)로써 유사한 경향을 나타내었으나 농가의 사육경험에 따라 6년 이상에서는 84.0%(105/125)였고, 10년 이상에서 88.4%(146/165)로써 사육경험이 많을수록 육성율이 우수하였다. 4. 발정유기방법별 분만후 발정재귀일수는 대조구에서 80.7일, PGF₂α 구에서 92.3일, PRID 구에서 78.5일, CIDR 구에서 64.5일, GnRH-PGF₂α-GnRH 처리구에서 65.6 일로 나타났고 분만 후 수태일수는 대조구에서 137.1일, PGF₂α 구에서 147.6 일, PRID구에서 141.3일, CIDR구에서 116.6일, GnRH-PGF₂α-GnRH 처리구에서 118일로 나타났으며 평균 134.3일이었다.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.86-86
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• 2003

한우의 사육규모가 커짐에 따라 농가에서 암소의 번식관리는 더욱 어려워지게 되었으며 이를 효율적으로 조절하고자 다양한 발정제어 처리에 따라 수태시켰으며 이에 따라 임신한 한우번식우의 분만내역과 다음번 번식에 미치는 영향을 규명하고자 수행하였다. 1) 발정유기 방법별분만율은 PeGF$_2$$\alpha$구에서 73%(73/100), PRID구에서 73.3%(22/30), CIDR구에서 76.6%(23/30), GnRH-PGF$_2$$\alpha$-GnRH 처리구에서 81%(81/100)였으며 전체적으로 76.5%(199/260)로 나타났다. 2) 생시체중은 자연발정구에서 암송아지는 23.9kg, 수송아지는 26.2kg인 반면에 발정유기구에서는 암송아지는 24kg, 수송아지는 24.9kg으로써 거의 차이를 보이지 않았고, 4개월령 체중에 있어서도 자연발정구에서 암송아지 72kg, 수송아지 75kg인 반면에 발정유기구에서는 암송아지 75.6kg, 수송아지 78.3kg으로 발육상에 차이가 없었다. 3) 송아지 육성율은 자연발정구에서 86.5%(251/290)이었으며, 발정유기구에서는 87.0% (175/201)로써 유사한 경향을 나타내었으나 농가의 사육경험에 따라 6년 이상에서는 84.0% (105/125)였고, 10년 이상에서 88.4%(146/165) 로써 사육 경험이 많을수록 우수하였다. 4) 분만후 발정재귀일수는 대조구에서 80.7일, PGF$_2$$\alpha$구에서 92.3일, PRID구에서 78.5일, CIDR구에서 64.5일, GnRH-PGF$_2$$\alpha$-GnRH 처리구에서 65.6일로 나타났고 분만 후 수태일수는 대조구에서 137.1일, PGF$_2$$\alpha$구에서 147.6일. PRID구에서 141.3일, CIDR구에서 116.6일, GnRH-PGF$_2$$\alpha$-GnRH 처리구에서 118일로 나타났다.

• Korean Journal of Veterinary Research
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• v.57 no.3
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• pp.155-158
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• 2017

Surgical castration performed to reduce male-associated problems results in pain and microbial infections in male animals. Therefore, immunocontraception, which is mediated by the animal's own antibodies against reproductive hormones, has been recommended as an alternative to surgical castration when considering the animal's welfare. In this study, a new immunocontraceptive vaccine composed of six tandem copies of gonadotropin-releasing hormone (GnRH) fused to rat granulocyte-macrophage colony-stimulating factor (GM-CSF) was developed, and its efficacy was evaluated in male rats. Three different doses (10, 50, and $100{\mu}g$) of recombinant GM-CSF-GnRH protein were injected three times at intervals of two weeks into male rats. The rats vaccinated with three doses of GM-CSF-GnRH produced a significantly higher level of antibodies against GnRH than that in the negative control rats. Severe atrophy of gonads was observed in rats vaccinated with three doses of GM-CSF-GnRH but not in the negative control rats. The results reveal that the new GnRH vaccine conjugated with rat GM-CSF induces efficient immunocontraception in male rats. This formulation of the immunocontraceptive vaccine would be applicable to both domestic and pet male animals.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.897-900
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• 2000

The experiment was conducted to study the effect of GnRH administration at induced estrus on pituitary and ovarian response in buffalo heifers. Eight Murrah river buffaloes of 12 to 13 months of age were treated with $PGF_{{2}{\alpha}}$ and eCG combination. GnRH (Fertagyl) 200 ug was injected (iv) at estrus in four heifers (treated group) while saline (2 ml, iv) was injected in remaining four heifers (control group). Blood was collected through jugular catheter to estimate plasma FSH, LH and estradiol level. The pretreatment plasma FSH, LH and estradiol values ranged from $8.46{\pm}1.97ng/ml$ to $12.31{\pm}1.30ng/ml$, $0.87{\pm}0.21ng/ml$ to $1.19{\pm}0.29ng/ml$ and $19.09{\pm}2.38pg/ml$ to $20.24{\pm}1.00pg/ml$ respectively. The plasma estradiol concentration elevated significantly (p<0.05) within 24 hr after eCG administration and reached its peak levels of $154.09{\pm}17.28pg/ml$ and $181.95{\pm}31.82pg/ml$ at estrus in respectively treatment and control groups. The plasma FSH and LH concentrations did not increase during follicular development after eCG administration while initial significant (p<0.05) increases in both plasma FSH and LH concentrations occured within 5 and 10 min, reaching peak levels of respectively $110.06{\pm}23.56ng/ml$ and $13.15{\pm}3.13ng/ml$ within 90 min after GnRH injection was detected. A sharp and significant decline in plasma estradiol concentration ($59.27{\pm}8.78pg/ml$) associated with synchronized ovulation within 24 hours after GnRH injection was recorded. The observation suggest that the hypophysis of prepubertal buffaloes treated with eCG have gonadotrophins awaiting the releasing factor to evoke release of gonadotrophin during the follicular phase to induce synchronized ovulation.