• Development and Reproduction
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• v.22 no.2
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• pp.119-132
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• 2018

GnRH (gonadotropin-releasing hormone) is a supreme hormone regulating reproductive activity in most animals. The sequences of amino acid and nucleic acid of GnRH reported up to now are examined from the evolutionary framework of Chordata. All identified GnRH are classified into GnRH1, GnRH2, or GnRH3. In all three forms of GnRH both N-terminal and C-terminal are conserved, which allows for effective binding to their receptors. The three amino acids in the middle of GnRH1 sequence have altered diversely from the primitive Chordata, which is indicative of the adaptation process to the ambient environment. GnRH2 and GnRH3 sequences are well conserved. There are more diverse modifications in the nucleic acids than in amino acid sequence of GnRH1. These variations can result from meiosis, mutation, or epigenetics and indicate that GnRH is the product of natural selection.

• Journal of Aquaculture
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• v.11 no.4
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• pp.513-519
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• 1998

Ovulation of maturing femal mandarin fish, Siniperca scherzeri was induced using single injection of human chorionic gonadotropin (HCG) or gonadotropin releasing hormone-analogue (GnRH-a), GnRH-a plus prostaglandin F2 (PG$F_2$) or GnRH-a plus pimozide. The response was evaluated by fertilization, embryo-formation and hatching rate after insemination. Those rates were generally higher in GnRH-a group than in HCG group. The higher hatching rat of above 89% was achived using a dosage of 5,000 IU/kg HCG plus 10 ${\mu}$g/kg GnRH-a, 10${\mu}$g/kg GnRH-a plus 500 ng/kg PGF2, and 10 ug/kg GnRH-a plus 1-5 mg/kg pimozide. Ovulation was induced in all female injected with sex-maturation hormones and stimulator, but blocked in female injected with HCG plus GnRH-a plus dopamine combination, and GnRH-a plus PGF2 plus indometacin combination. These results show that the mandarin fish in spawning period secrete a sex-mutruation assosiated hormones and gonadotropin-releasing -inhibiting factor(GRIF).

• Animal cells and systems
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• v.3 no.1
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• pp.1-7
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• 1999

Gonadotropin-releasing hormone (GnRH) was originally isolated as a hypothalamic peptide that regulates reproduction by stimulating the release of gonadotropins. Using comparative animal models has led to the discovery that GnRH has a more ancient evolutionary origin. Durinq evolution GnRH peptide underwent gene duplication and structural changes to give rise to multiple molecular forms of GnRHs. Mammalian GnRH initially considered to be the sole molecular form, is now grouped as a family of peptides along with GnRH variants determined from representatives in all classes of vertebrates. Vertebrate species including primates and humanshave more than one GnRH variant in individual brains; a unique GnRH form in the forebrain and chicken IIGnRH in the midbrain. Furthermore, several species of bony fish have three molecular variants of GnRH: salmon GnRH sea-bream GnRH and chicken II GnRH. Also, it has been shown that in addition to the olfactory placodes and the midbrain, there is a third embryonic source of GnRH neurons from the basal diencephalon in birds and fish, which might be true for other vertebrates. Therefore, comparative animal models like fish with discrete sites of expression of three molecular variants of GnRH in individual brains, could provide insight into novel functions of GnRH variants, conservation of gene regulation, and mechanisms governing reproduction in vertebrates.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.11 no.1
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• pp.23-32
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• 1981

The purpose of this study was to assess temporomandibular joint subluxation by means of cephalometry using two lateral cephalograms from each person with in centric occlusion and wide-open mouth position, and to compare patient group with subluxation to normal control group in the measurements and correlation coefficient. The 200 cephalograms of 100 Korean adults, patient group consisted of 24 females and 26 males ranged from 17 to 63 years age and the normal control group consisted of 20 females and 30 males ranged from 18 to 56 years age, were studied and analyzed statistically. The results were as follows; 1. In the comparison of patient group vs normal control group in the measurements, statistically significant differences were found in C-C', C'-PTM, K-FH, K-PTM, Gn-Gn', C-S-C', Gn-S-Gn', Gn-K-Gn', GoGn-SN, and GoGn-Go'Gn'. K-point* of patient group was located antero - superiorly than of normal control group, and the significance level was higher in K-PTM than in K-FH. There was no statistically significant difference found in local relationship of C-point between patient group and normal control group. The values of correlation coefficient among all measurements were in 0.958≥r≥-0.760, and the highest value was in Gn-Gn' to GoGn-Go'Gn' and Gn-K-Gn' to Gn-Gn', and the lowest value was in C'-PTM to Gn-K-Gn' of normal control group. K was determined as a point of intersection by a perpendicular bisector of Gn-Gn' and a perpendicular bisector of C-C'.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.5 no.1
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• pp.103-118
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• 1999

The activity of N-acetylglucosamitnyltransferase(GnT) III and V on a Melanoma B-16 was examined after incubation with interleukin 1 (IL-1). While augumenting cell proliferation, IL-1 resulted in a decrease of GnT-III activity and an increase of GnT-V activities. Consistant with this, Melanoma B-16 cultured with IL-1 showed increased affinlity to Daturam stramonium lectin, which recognizes asialo-tri- and asialeo-tetra-antenery N-linked oligosaccharides. These results indicate that IL-1 modulate glycosyltransferase activity and the oligosaccharide structure of target cells. On the other hand, to investigate whether or not TKM-SG affect GnT-V gene expression in lung metastatic carcinoma, we used RT-PCR methods. TKM-SG treated cell lines showed low levels of secretion of GnT-V mRNA transcription as elucidated by RT-PCR. Thus, with together lower GnT-V activity levels in the medium, TKM-SG was highly effective for lung cancer metastasis treatment and it was concluded that the medicine can be used as a potent anti-lung cancer metastasis medicine.

• Animal cells and systems
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• v.2 no.4
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• pp.483-488
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• 1998

We previously found that a potent gonadotropin-releasing hormone (GnRH) agonist, buserelin, decreases GnRH promoter activity together with GnRH mRNA level, providing evidence for an autoregulatory mechanism operating at the level of GnRH gene transcription in immortalized GT1-1 neuronal cells. To examine whether agonist-induced decrease in GnRH mRNA level requires the continuous presence of buserelin, we performed a pulse-chase experiment of buserelin treatment. Short-term exposure (15 min) of GT1-1 neuronal cells to buserelin ($10{\mu}M$) was able to decrease GnRH mRNA levels when determined 24 h later. When GT1-1 cells were treated with buserelin ( $10{\mu}M$) for 30 min and then incubated for 1, 3, 6, 12, 24, and 48 h after buserelin removal, a significant decrease in GnRH mRNA levels was observed after the 12 h incubation period. These data indicate that inhibitory signaling upon buserelin treatment may occur rapidly, but requires a long time (at least 12 h) to significantly decrease the GnRH mRNA level. To examine the possible involvement of de novo synthesis and/or mRNA stability in buserelin-induced decrease in GnRH gene expression, actinomycin D ($5{\mu}m/ml$), a potent RNA synthesis blocker, was co-treated with buserelin. Actinomycin D alone failed to alter basal GnRH mRNA Revel, but blocked the buserelin-induced decrease in GnRH mRNA level at 12 h of post-treatment. These data suggest that buserelin may exert its inhibitory action by altering the stability of GnRH mRNA. Moreover, a polvsomal RNA separation by sucrose gradient centrifugation demonstrated that buserelin decreased the translational efficiency of the transcribed GnRH mRNA. Taken together, these results clearly indicate that GnRH agonist buserelin acts as an inhibitory signal at multiple levels such as transcription mRNA stability, and translation.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.78-83
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• 1998

The objective of this study was to investigate the responsiveness of hypophysis and gonads to synthetic GnRH among prepubertal buffalo heifers at 12 months of age. Peripheral plasma FSH, LH, estradiol and progesterone level were measured in blood samples collected at 1 hr before and up to 18 days subsequent to the administration of $200{\mu}g$ GnRH (n=6) or saline (n=6) in Murrah buffalo heifers. The pretreatment peripheral plasma FSH, LH, estradiol and progesterone among GnRH treated heifers were $7.35{\pm}0.45ng/ml$, $1.08{\pm}0.3ng/ml$, $22.93{\pm}1.06pg/ml$ and $0.27{\pm}0.04ng/ml$ respectively. A quick elevation (p < 0.01) of FSH and LH within five min of GnRH administration was observed in all geifers. Although the peak FSH $(89.57{\pm}23.43ng/ml)$ and LH $(7.52{\pm}3.08ng/ml)$ reached by 10 min of GnRH administration, yet the animals differed both in terms of their amplitude response of FSH and LH release as well as in terms of time which animals took to exhiit maximum response to GnRH administration. The GnRH administration did not cause alteration in plasma estradiol and progesterone level. The present study suggests that the pituitary of 12 month buffalo heifers has capacity to synthesize and store of gonadotropin and have developed receptors for GnRH for a spike of gonadotropin release.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.207-213
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• 2003

This objective of this experiment were to evaluate the effect of various estrus synchronization programs on estrus detection rate and pregnancy rate in Hanwoo. After Postpartum 60 Days, a total of 150 cows divided into 2 groups. Cows Group 1 were treated with one luteolytic dosage of PGF$_2$$\alpha$(25 mg, im; lutalyse. USA) on Day 0, and with a second dosage 14 d later; cows in Group 2 were treated with GnRH(l00 $\mu\textrm{g}$, im; Conceral. Korea) on Day 0, PGF$_2$$\alpha$ 7 d later, GnRH 2 d later, and then time-inseminated approximately 16 h after this second treatment with GnRH. Ovarian morphology was monitored cows by trans-rectal ultrasonography from 24 hr to 32 hrs after second GnRH injection. The result obtained summarized as follows: 1. Cows synchronization of estrus with GnRH+PGF$_2$$\alpha$+GnRH(Ov-synch) and PGF$_2$$\alpha$ were 91.3 and 40.0%, respectively. 2. Induced ovulation were 24 to 32hr after the second GnRH injection, but high induced ovulation was 28hr. 3. High conception rate were 24hr insemination after the second GnRH injection. 4. Conception rate with PGF$_2$$\alpha$, CIDR and GnRH treatment were 50.0, 36.0 and 76.9%, respectively.

• Journal of Veterinary Clinics
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• v.3 no.1
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• pp.227-233
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• 1986

A total of 600 Holstein cows in Chonnam province was examined to make a diagnosis on the ovarian follicular cyst. By clinical signs and rectal examination, 57 cows were found to have ovarian follicular cyst. Attempts were made to treat the cows which had ovarian follicular cyst with GnRH, HCG respectively. The results obtained were summarized as follows : 1. The rates of estreous induction with GnRH or HCG were 91.4%, 77.2%, respectively. The GnRH treated group was showed significantly higher than HCG treated group. The mean days from the GnRH or HCG treated to estrum were 25.1 and 23.5 days, respectively. 2. The Conception rates with GnRH or HCG treatment were 78.2% and 76.5％, respectively. 3. Services per conception with GnRH or HCG treatment were 1.5 and 2.1 respectively. 4, Days from GnRH or HCG treatment to concept were 38.2 and 45.8 days, respectively. 5. Intramuscular injection with GnRH and intraovarian injection with HCG were revealed the most effective routes in all the other routes.

• 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.