• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.192-200
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• 2019

Objective: Leukemia inhibitory factor (LIF) binds to a heterodimeric receptor composed of LIF receptor (LIFR) and glycoprotein 130 (GP130) to transmit signals into the cell. LIF plays an important role in reproduction by regulating immune response, decidualization, and implantation in several species. However, the expression of LIF and LIFR in the endometrium throughout the estrous cycle and pregnancy in pigs is not fully understood. Methods: We analyzed the expression of LIF and LIFR in the endometrium on days 0 (estrus), 3, 6, 9, 12, 15, and 18 of the estrous cycle, and days 12, 15, 30, 60, 90, and 114 of pregnancy, in conceptuses on days 12 and 15, and in chorioallantoic tissues on days 30, 60, 90, and 114 of pregnancy in pigs. We also determined the effects of estrogen and progesterone on the expression of LIF and LIFR in endometrial tissues. Results: The expression of LIF increased in the endometrium during the late diestrus phase of the estrous cycle and during mid- to late- pregnancy, while the expression of LIFR increased during early pregnancy. The expression of LIF was induced by increasing doses of estrogen, whereas the expression of LIFR was induced by increasing doses of progesterone. Conclusion: These results indicate that the expression of LIF and its receptor LIFR in the endometrium is regulated in a stage-specific manner during the estrous cycle and pregnancy, suggesting that LIF and its receptor signaling system may play critical roles in regulating endometrial function in pigs.

• 한국수정란이식학회지
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• 제33권4호
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• pp.297-304
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• 2018

The purpose of the present study was to determine the elaborate characteristics of ovarian changes including follicles and corpus luteum, and hormonal patterns of gonadotropin surge mode secretions during the normal consecutive estrous cycle in three dairy cows. Non-lactating and multiparous Holstein cows (n=3) used as experimental animals. The cows were assigned to examine the relationship among ovarian changes (follicle, corpus luteum), ovarian steroids (estradiol, progesterone) and gonadotropin (LH, FSH) surge mode secretion during the successive estrous cycles by rectal palpation, ultrasonography and hormonal assay. The mean length of the estrous cycle for the three cows was $23.1{\pm}1.44days$ (${\pm}SEM$), with a range of 20-28 days. In six estrous cycles, the number of two follicular waves, three follicular waves and four follicular waves was 2, 3 and 1, respectively. The sequential ultrasonographic monitoring showed that the corpus luteum with ${\geq}10mm$ in diameter detected from Day 2 (Day 0 is ovulation) in six estrous cycles of all cows. Preovulatory increases in estradiol concentration reached $10.36{\pm}1.10pg/ml$ on the 2 days before ovulation of the last dominant follicle. All cows exhibited a preovulatory rise in estradiol concentration followed by a typical preovulatory LH and FSH surge. The mean interval from the peak of LH/FSH surge to ovulation of the last dominant follicle was $31.3{\pm}1.76h$ (${\pm}SEM$). In these results, each dairy cow showed that ovarian morphological changes and gonadotropin surge mode secretion will be regulated by various environmental factors including age, breeds, nutrition, breeding conditions, etc.

• 한국수정란이식학회지
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• 제24권3호
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• pp.159-167
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• 2009

Ultrasonographic examination was performed to observe the ultrasonographic image of Korean native cows' normal uterus in condition of in vitro and in vivo. The experiment was done 28 slaughtered cows' uterus using immersed in water in vitro, and 41 healthy breeding cows taken rectal ultrasonography in vivo. Ultrasonographic examination of uterine was taken on the reference of cross section of intercornual ligaments' cranial. Each uterus on the experiments was compared by estrous cycle and ultrasonographic frequency. The uterine structure using ultrasonography was 5 layers of uterine horn in vivo as well as in vitro. Uterine horn was observed to be distinguished from inside to outside as endometrium to inner echogenic layer, circular muscle layer to slightly echogenic elliptical layer, stratum vasculare to central echogenic layer, longitudinal muscle layer to slightly echogenic arched layer, and perimetrium to outer echogenic layer, respectively. According to the observation of uterus related to estrous cycle and ultrasonographic examination, uterine endometrium in vitro was constantly founded irrespective of estrous cycle and ultrasonographic frequency. On the low frequency, endometrium and circular muscle layer in estrus were prone to distinguished than in diestrus. On the high frequency, endometrium and circular muscle layer were always distinguished regardless of estrous cycle. In vivo, uterine endometrium and circular muscle layer were observed regardless of estrus and ultrasonographic frequency. On the low frequency, stratum vasculare and longitudinal muscle layer were not likely to be distinguished in diestrus, but estrus. On the high frequency, stratum vasculare and longitudinal muscle layer were observed regardless of estrous cycle. Also, every uterine structure was easily distinguished on high frequency than low frequency owing to precision of distinction in layers. The difference of results followed by the experiments conditions between in vitro and in vivo was that uterine endometrium and circular muscle layer in diestrus in vitro were difficult to be distinguished and uterine lumen was observed during whole estrous cycle. In vivo, It was founded that the distinction of stratum vasculare and logitudinal muscle layer in diestrus was complicated and uterine lumen was observed during only estrus. In view of the result so far achieved, normal uterine structure divided in 5 layers on ultrasonography was accorded with microscopic organization, uterine structure was likely to be observed during estrus than diestrus, high frequency checkup than low frequency, and uterine endometrium, circular muscle, stratum vasculare was easily observed regardless of estrous cycle and ultrasonographic frequency.

• 한국발생생물학회지:발생과생식
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• 제6권2호
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• pp.123-129
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• 2002

비만유전자 산물인 leptin은 비만뿐만 아니라 여성의 생식 생리와 관련이 있는 것으로 보이나, 아직 이러한 leptin이 난소에 직접적으로 작용하는지 정확하게 밝혀지지 않고 있다. 따라서 본 연구에서는 흰쥐 난소에서 leptin과 leptin 수용체의 발현을 면역조직화학방법으로 확인하고 발정주기에 따른 leptin과 leptin 수용체의 발현 양상을 RT-PCR 방법으로 조사하고자 하였다. 면역조직화학적 염색방법 결과 흰쥐 난소내에서 leptin은 협막세포와 폐쇄 난포의 일부 과립세포에 염색되었고, leptin 수용체는 협막세포, 간질세포와 난포강이 형성되지 않은 난포의 난자에 염색되었다. 특히 폐쇄 난포에서는 leptin과 leptin 수용체가 정상 난포에 비해 강하게 염색되었다. 흰쥐의 발정주기 동안 혈청내 estradiol, progesterone leptin의 농도는 ELISA 방법으로 측정하였고, 난소내 leptin과 leptin 수용체의 mRNA 발현 양상은 RT-PCR 방법으로 조사하였다. 혈중 leptin 농도를 측정한 결과 estrous 시기에 비하여 metestrous 시기에 유의하게 증가하였고, 이 시기에 progesterone 농도가 함께 증가하는 것을 관찰할 수 있었다. Leptin mRNA는 모든 발정주기에서 발현되지 않았지만 leptin 수용체 mRNA는 diestrous 시기를 제외한 다른 발정주기에 모두 발현되었다. 이러한 결과는 leptin이 흰쥐 난소의 기능을 조절하는데 직접적으로 관여할 수 있다는 것을 제시하고 있다.

• Reproductive and Developmental Biology
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• 제41권1호
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• pp.1-6
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• 2017

In all mammalian species, progesterone is essential to both the preparation for, and maintenance of, pregnancy. The $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) enzyme predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone, thereby regulating its activity. Thus, to directly assess sexual maturation in the MediKinetics $micropig^{(R)}$, we analyzed the concentration of the steroid hormones progesterone and estradiol during the estrous cycle. Our results show that the progesterone level exhibited by the analyzed $micorpig^{(R)}$ was low at the beginning of the estrous cycle, and then abruptly increased to $30.32{\pm}10.0ng/mL$ and $46.37{\pm}11.0ng/mL$ by days 9 and 11 of the cycle, respectively. It reached the highest level $55.87{\pm}3.5ng/mL$ on day 13 of the estrous cycle, before decreasing to $46.58{\pm}13.1ng/mL$ and $10.0{\pm}7.6ng/mL$ by days 15 and 17 of the cycle, respectively. In contrast, the estradiol level was shown to be highest ($27.13{\pm}11.2ng/mL$) at the initiation of the estrous cycle, after which point it decreased to $13.29{\pm}6.5ng/mL$ and $10.94{\pm}5.9ng/mL$ by days 4 and 5 of the estrous cycle, respectively. By day 17 of the estrous cycle, the estradiol level decreased to $4.13{\pm}7.6ng/mL$. We anticipate that these results will provide useful information to enable the study of human ovulation and reproductive physiology using the MediKinetics $micoripig^{(R)}$ as a model system. We recommend further investigation to elucidate the functional mechanisms underlying the regulation of sexual maturation in the MediKinetics $micropig^{(R)}$.

• 한국수정란이식학회지
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• 제22권1호
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• pp.15-19
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• 2007

본 연구는 번식 효율 증진을 위해 BCS, BUN과 발정 발현과의 관계를 조사하였으며, 공시된 홀스타인 젖소 51두 중 37두에서 배란 및 28두에서 발정 발현을 확인하였다. 발정 유기율에서 BCS $2.0{\sim}2.49$와 $2.5{\sim}3.0$인 우군에서는 각각 78.9% 및 73.9%인 반면 2.0 미만인 우군에서는 55.6%로 유의적인(p<0.05)차이를 보였으며, 발정 발현율과 승가 허용율에서도 BCS $2.0{\sim}2.49$인 우군에서 각각 73.3% 및 46.7%이고 BCS $2.5{\sim}3.0$인 우군은 각각 88.2% 및 64.7%를 보인 반면 BCS 2.0 미만인 우군에서는 각각 40% 및 0%로 BCS 2.0 이상인 우군에 비해 유의적(p<0.05)으로 낮게 나타났다. 발정 동기화 우군의 BUN과 발정 발현율과의 관계에서 BUN 수준이 10mg/dl 이상인 우군에서 85.7%의 발정 발현율를 보인 반면 10 mg/dl 이하인 우군에서는 52.1%로 유의적으로(p<0.05) 낮게 나타났다. 발정 행동별(외음부 냄새 맡기, 턱비빔, 승가 및 승가 허용) BUN 수준에 있어서는 영향을 미치지 않는 것으로 나타났다. 발정 발현율과 BUN 수준은 초산우와 2산 이상우 사이에서 유의적인 차이를 보이지 않았다. 본 연구의 결과 BCS와 BUN 수준이 낮으면 발정 발현에 영향을 미치는 것을 알 수 있다. 발정 발현율이 점차 떨어지고 있는 현 시점에서 효율적인 영양관리가 뒷받침되어야 번식 효율이 향상될 것으로 생각된다.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.349-353
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• 2011

The objective of this study was to investigate the relationship between estrous expression, body condition score (BCS), blood urea nitrogen (BUN) and number of transferable embryos for the purpose of improving reproductive performance in blood of Hanwoo donors. Sixty, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg PGF2 ${\alpha}$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received 100 ${\mu}g$ GnRH at the time of 1nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The estrous inducement rate and estrous expression rate were significantly lower for cows with BCS below 2.25 than for cows with BCS above 2.25. There was 50.0% of rate of mounting in cows with BCS below 2.25 whereas the rate of mounting was markedly increased in cows with BCS above 2.25 (94.1% and 89.5% for BCS 2.25~2.75 and BCS above 2.75 cows, respectively). Cows with BCS <2.25, 2.25~2.75 and ${\geq}$2.75 had number of transferable embryos of $4.5{\pm}0.7$, $5.9{\pm}1.8$ and $5.6{\pm}2.3$ respectively.

• 한국수정란이식학회지
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• 제22권1호
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• pp.47-51
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• 2007

더러브렛종 암말의 번식 능력을 향상시키기 위해 호르몬 투여 및 인공 조명에 의한 인위적으로 발정 조절을 실시한 결과는 다음과 같다. 발정 주기에 있는 암말의 $PGF_2{\alpha}$ 또는 altrenogst투여에 의한 발정 발현율은 100%이었으며, 수태율은 각각 95.2% 및 71.4%였다. 전년도 공태마에 대하여 altrenogest단독 또는 altrenogest과 estradiol 병행 투여시 3월 이내 100% 발정이 발현되었으며, 발정 발현일은 altrenogest 투여 종료 후 단독 투여군이 4.3일, estradiol 병행 투여군이 3.7일이었고, 배란일은 발정 발견 후 각각 2.7일과 2.5일이었고, 처리군간의 유의적인 차이는 없었다. 그리고 수태율은 altrenogest 단독 투여군이 80.0%를 나타내었다. 인공 조명에 의한 발정 발현율은 92.9%였고 수태율은 76.9%였다. 이상의 결과로 보아 번식 계절에 있는 암말에 대한 발정 동기화는 수태율을 높일 수 있는 수단으로 활용될 수 있고, 전년도 비임신으로 공태중인 암말에 altrenogest 투여는 경주마의 조기 번식 및 수태율 향상에 기여할 수 있을 것으로 사료 된다.

• 한국가축번식학회지
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• 제15권1호
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• pp.59-66
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• 1991

在來山羊의 發情週期와 發情持續期間을 조사하고자 정관 절제 시술한 시정모 산양을 이용하여 90두의 암산양으로부터 3년간에 걸쳐 총 148회의 방정주기를 관찰하였다. 총 481회의 발정주기의 평균기간은 18.1${\pm}$0.5이었고, 11일 이하의 短發情週期가 143회(30%), 12일에서 16일의 中發情週期가 15회(3%), 17일에서 24일의 正常發情週期가 268회(56%) 및 25일 이상의 長發情週期가 55회(11%)로 나타났다. 短發情週期의 발생율은 자연발정후(27%)보다 유기발정후(15.2${\pm}$0.8)일에 유의적(P<0.01)으로 짧았다. 短發情週期에 있어서는 143회중 6일의 기간을 가지는 빈도가 92회로 가장 많았다. 발정지속 시간의 평균은 34.0${\pm}$0.5시간이었는데, 발정지속시간에 있어서는 자연발정과 유기발정간에 유의적인 차이가 없었다. 이상의 결과로 在來山羊의 發情週期는 自然發情後에 있어서 보다 誘起發情間에 차이가 없음을 알 수 있다.

• 대한수의학회지
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• 제30권2호
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• pp.243-247
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• 1990

A study was conducted to improve the reproductive performance of Korean native cows. Plasma progesterone concentrations were determined by radioimmunoassay during the estrous cycle and early pregnancy. Plasma progesterone concentrations during the estrous cycle in the 15 cows were the lowest (0.30ng/ml) at estrus, gradually increased after 6 days, remained high from 8 to 17 days (3.87~5.59ng/ml) and drastically decreased thereafter to reach minimal concentrations at the next estrus. Plasma progesterone concentrations of the 10 pregnant cows at 20 days after insemination were $5.82{\pm}1.33ng/ml$ (mean${\pm}$SD) and those of 10 non-pregnant cows were $0.30{\pm}0.21ng/ml$, respectively. Therefore, plasma progesterone concentrations in the pregnant cows at 20 days after insemination were significantly higher than in non-pregnant cows (p<0.001).