• Korean Journal of Animal Reproduction
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• v.9 no.1
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• pp.31-35
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• 1985

This study was carried out with 46 cows to investigate the ovarian response to the administration of PMSG, PGF2$\alpha$ and hCG, and the developmental stage of embryos recovered. Superovulation was induced by the injection of 2,000IU to 3,000IU PMSG on the days of 7-13 of the estrus cycle followed 48 hours later by the injection of 22.5mg PGF2$\alpha$. Of 29 cows treated with 3,000IU PMSG and 22.5mg PGF2$\alpha$ 18 cows were given 2,000IU hCG at the onset and 7 after artificial insemination. The results obtained were summarized as follows; 1. The number of developed follicles per cow after an injection of 2,000, 2,500, 3,000IU of PMSG and 3,000 PMSG-2,000IU hCG in combination with 22.5mg PGF2$\alpha$ were 12.6, 19.6, 21.5 and 29.3, respectively. This result indicated that the no. of developed follicles per cow was increased according to the increase of PMSG dosage and the combination with hCG injection. 2. The highest number of ovulation was 17.1 in cows treated with PMSG-hCG and the number of matured corpus luteum was increase as the dosage of PMSG was higher. 3. Ovulation rate from cows treated with 2,500IU PMSG was 71.0% and this reulst was higher than the average of ovulation rate (59.3%). 4. Average recovery rate was 36.8%(232/631), and the number of ova per cow was 5.0. 5. Of 232 recovered embryos, the number of morulae and blastocysts were 76 (32.8%) and 83 (35.8%), respectively. 6. 28.4% of total recovered embryos was abonormal morphologically.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.384-388
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• 2003

To establish the method of estrus induction using the injection of PGF$_2$$\alpha$ㆍ the 60 dairy cows treated by PGF$_2$$\alpha$ㆍ at 6, 8, 10, 12, 14, and 16 day of estrous cycle, recpectively. The plasma progesterone concentrations at day of injection of PGF$_2$$\alpha$ㆍ were $1.5\pm$1.3 (mean$\pm$SD) ng/ml at 6 days of estrous cycle, 3.7$\pm$1.4 ng/ml at 8 days, 6.5$\pm$1.8 ng/ml at 10 days, 7.9$\pm$2.0 ng/ml at 12 days, 6.5$\pm$2.5 ng/ml at 14 days, and 2.5$\pm$1.2 ng/m] at 16 days, respectively. The percentages of induction of estrus after PGF$_2$$\alpha$ㆍ treatment were 52.8% at 3th day after treatment, 21.7% at 4th day, 8.3% within 2th day, and ] 7.2% after 5th day, respectively. The percentages of cows conceived at first service after induction of estrus were 73.3% on 16 days of estrous cycle at treatment, 66.7% on 10 and 14 days, 63.3% on 8 and 12 days, and 53.3% on 6 day, respectively. The percentages of cows conceived on first service were 70.5% at 3th day after induction, 66.7% at 4th day and 65% at 5th day, respectively. These results suggest that the PGF$_2$$\alpha$ㆍ treatment at regressing stage of corpus luteum showed high induction of estrus and pregnancy rate, and there were high induction of estrus and pregnancy rate at 3th and 4th day after PGF$_2$$\alpha$ㆍ treatment.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.1
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• pp.21-28
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• 1986

It is now apparent that many cases of amenorrhea. oligomenorrhea. corpus luteum deficiency, galactorrhea, and infertility are due to hyperprolactinemia. We investigated the relationships between serum prolactin values and factors such as menstrual pattern, frequency of galactorrhea etc, in 135 hyperproIactinemic patients at the Seoul National University Hospital during a period of 6 years, from January, 1979 to December, 1984. The results was as follows: 1. Menstrual pattern changed according to the serum prolactin level. The frequency of amenorrhea is 1.7 percent in patients with serum prolactin levels ranged from $25{\sim}40ng/ml$, whereas 72.4 percent in patients with serum prolactin levels above 100ng/ml. 2. The incidence of galactorrhea in hyperprolactinemic patients was 3.1 percent and the frequency of galactorrhea had direct relationship with the serum prolactin level and/or the frequency of abnormal menstrual pattern. 3. The incidence of pituitary tumor in hyperprolactinemic patients was 104 percent and sixty percent of patients with serum prolactin levels above 100ng/ml had a pituitary tumor . 4. There was an inverse correlation between serum prolactin and progesletone value. 5. The frequency of anovulatory menstrual cycle evidenced by basal body temperature is 23.9 percent in patients with serum prolactin levels ranged from $20{\sim}40ng/ml$, whereas 76.9 percent in patients with serum prolactin levels above 100ng/ml.

• Reproductive and Developmental Biology
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• v.42 no.2
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• pp.7-12
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• 2018

In this review, we have tried to summarize the evidence and molecular characterization indicating that $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) is a group of the aldo-keto reductase (AKR) family, and it plays roles in the modulation and regulation of steroid hormones. This enzyme plays a critical role in the regulation of luteal function in female mammals. We have studied the molecular expression and regulation of $20{\alpha}$-HSD in cows, pigs, deer, and monkeys. The specific antibody against bovine $20{\alpha}$-HSD was generated in a rabbit immunized with the purified recombinant protein. The mRNA expression levels increased gradually throughout the estrous cycle, the highest being in the corpus luteum (CL) 1 stage. The mRNA was also specifically detected in the placental and ovarian tissues during pregnancy. The $20{\alpha}$-HSD protein was intensively localized in the large luteal cells and placental cytotrophoblast villus, glandular epithelial cells of the endometrium, syncytiotrophoblast of the placenta, the isthmus cells of the oviduct, and the basal part of the primary chorionic villi and chorionic stem villus of the placenta and large luteal cells of the CL in many mammalian species. Further studies are needed to determine the functional significance of the $20{\alpha}$-HSD molecule during ovulation, pregnancy, and parturition. This article will review how fundamental information of these enzymes can be exploited for a better understanding of the reproductive organs during ovulation and pregnancy.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.22-29
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• 1998

To investigate the estrual changes of ovaries, appropriate time of mating, diagnosis of early pregnancy after mating, and diagnosis of twin fetuses, ultrasonography was performed in 61 thorough-bred mares (5-12 years old) which had been raised in Chrju island. The followings are the results obtained: 1. The average size of a follicle of mares was $3.2{\times} 3.8cm$ at the beginning of estrus and $4.2{\times} 3.5 cm$ from the middle of estrus to ovulations respectively, and the average size of a follicle and a corpus luteum was $1.8{\times} 1.4 cm and 3.1{\times}2.3 cm$ in the middle of diestrus, respectively. 2. In the result of pregnancy according to mating time after ultrasonographic examination of follicle size, the mares having a follicle of 4.6-5.0 cm (diameter) were mated on the day of ultrasonographic examination or the next day rind all were conceived (3 mares) and another mares having a follicle of 4.1- 4.5cm (diameter) on the 1st or 2nd day after examination and all were conceived (4 mares). 3. By ultrasonographyi early pregnancy in the mares was diagnosed from 12 days of pregnancy and the equine fetus was directly detectable from 23 days of pregnancy, whereas the heartbeat of a fetus was detectable from 28 days of pregnancy. 4. Diagnosis of earl pregnancy of twin was possible from 16 days of pregnancy. These result indicated that ultrasonography is applicable in mares to diagnose the estrual changes of ovaries and the time of ovulation or mating, and to diagnose early pregnancy from 12 days of pregnancy and early pregnancy of twin fetuses.

• Development and Reproduction
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• v.25 no.4
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• pp.213-223
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• 2021

Controlled ovarian hyperstimulation (COH) is routinely used in the in vitro fertilization and embryo transfer (IVF-ET) cycles to increase the number of retrieved mature oocytes. However, the relationship between repeated COH and ovarian function is still controversial. Therefore, we investigated whether repeated ovarian stimulation affects ovarian aging and function, including follicular development, autophagy, and apoptosis in follicles. Ovarian hyperstimulation in mice was induced by intraperitoneal injection with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Mice subjected to ovarian stimulation once were used as a control group and 10 times as an experimental group. Repeated injections with PMSG and hCG significantly reduced the number of primary follicles compared to a single injection. The number of secondary and antral follicles increased slightly, while the number of corpus luteum increased significantly with repeated injections. On the other hand, repeated injections did not affect apoptosis in follicles associated with follicular atresia. The expression of autophagy-related genes Atg5, Atg12, LC3B, and Beclin1, cell proliferation-related genes mTOR, apoptosis-related genes Fas, and FasL was not significantly different between the two groups. In addition, the expression of the aging-related genes Dnmt1, Dnmt3a, and AMH were also not significantly different. In this study, we demonstrated that repeated ovarian stimulation in mice affects follicular development, but not autophagy, apoptosis, aging in ovary. These results suggest that repetition of COH in the IVF-ET cycle may not result in ovarian aging, such as a decrease in ovarian reserve in adult women.

• Journal of Veterinary Clinics
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• v.35 no.6
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• pp.251-257
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• 2018

We determined the relationships between calving season and the incidence of postpartum disorders, milk yield, and reproductive performance in dairy cows. Data regarding cow parity, postpartum disorders, milk yield, and reproduction were collected from 1,478 lactations. The incidence of retained placenta was higher in spring- and summer-calving cows than in autumn- and winter-calving cows (P < 0.05). The incidence of septicemic metritis was highest in spring- and summer-calving cows, and was higher in autumn-calving cows than in winter-calving cows (P < 0.05). The incidence of metabolic disorders was higher in summer-calving cows than in autumn- and winter-calving cows (P < 0.01). The mean milk yield 1 and 2 months after calving was higher in spring-calving cows than in summer-calving cows (P < 0.05). The percentage of cows that had resumed cycling, defined by detection of a corpus luteum using ultrasonography 4 weeks after calving, was highest in autumn-calving cows, and was higher in summer- and winter-calving cows than in spring-calving cows (P < 0.05). The hazard of first insemination by 150 days after calving was higher in summer- and autumn-calving cows (hazard ratio [HR] = 1.19; P < 0.05) than in spring-calving cows. The hazard of pregnancy by 210 days after calving was also higher in summer-calving (HR = 1.24; P < 0.05) and autumn-calving (HR = 1.59; P < 0.0001) cows than in spring-calving cows. The probability of conception at the first insemination was higher (P < 0.0001) in autumn-calving (odds ratio [OR] = 1.96) and winter-calving (OR = 2.04) cows than in spring-calving cows. In conclusion, spring calving is associated with the worst, and autumn calving with the best, postpartum health and reproductive performance, whereas milk yield is higher in spring-calving cows than in summer-calving cows. Therefore, an effective strategy to support postpartum health and fertility should be instituted for spring-calving dairy cows kept in the Korean climate.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.211-215
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• 2018

The following experiments were designed to examine the effect of serum of spayed dogs on superovulation response in mice and rats. In Experiment 1, female mice at diestrus (n=30) were divided into three equal groups and superovulated with either administration of 5 IU pregnant mare serum gonadotropin (PMSG) or recombinant follicle stimulating hormone (rFSH) (reducing dose from 2.5 to 0.5 IU) and 5 IU human chorionic gonadotropin (hCG) administered 48h later. Serum of spayed dogs was administered intraperitoneally at a reduced dose from 0.1 to 0.025 mL in a 48 h period. In Experiment 2, female rats (n=30) at diestrus stage were divided into three equal groups. Superovulation was induced using either 30 IU PMSG, or a dose reduced from 5 to 1 IU rFSH and 25 IU hCG administered 48h later. Serum of spayed dogs was administered in a reduced dose from 0.6 to 0.1 mL in a 48 hour period. Female mice and rats were mated 24 h following hCG administration. On day 14 after mating, animals were euthanized and ovarian sections were fixed for histopathological evaluation and corpus luteum (CL) counting. No significant difference observed in mean (${\pm}SEM$) number of CLs between the PMSG group and the mice that received serum of spayed dog ($10.4{\pm}1.3$ vs $9.2{\pm}1.0$). Mean (${\pm}SEM$) number of CLs tended to be lower in rats that received serum of spayed dog than those of rats which received either PMSG or rFSH ($15.1{\pm}1.9$ vs $23.6{\pm}3.1$ and $23.1{\pm}2.9$, P=0.06, respectively). In conclusion, serum of spayed dogs is able to induce a superovulatory response in mice and rats.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.3
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• pp.155-161
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• 2022

Pregnancy-associated plasma protein-A (PAPP-A) is known as an important biomarker for fetal abnormality during first trimester and has a pivotal role in follicle development and corpus luteum formation. And also, it is being revealed that an expression of PAPP-A in various cells and tissues such as cancer and lesion area. PAPP-A is the major IGF binding protein-4 (IGFBP-4) protease. Cleavage of IGFBP-4 results in loss of binding affinity for IGF, causing increased IGF bioavailability for proliferation, survival, and migration. Additionally, PAPP-A can be used as a promising therapeutic target for healthy longevity. Despite growing interest, almost nothing is known about how PAPP-A expression is regulated in any tissue. This review will focus on what is currently known about the zinc metalloproteinase, PAPP-A, and its role in cells and tissues. PAPP-A is expressed in proliferating cells such as fetus in uterus, granulosa cells in follicle, dermis in wound, cancer cells, and Sertoli cells in testis. They have common characteristics of proliferation faster than normal cells with stimulating IGFs action and inhibiting IGFBPs. The PAPP-A functions and expression studies in livestock have not yet been conducted much. Further studies are needed to use PAPP-A as a marker for healthy longevity in animal science.

• Development and Reproduction
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• v.26 no.4
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• pp.135-144
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• 2022

As the number of coronavirus disease 2019 (COVID-19) vaccinations increases, various side effects are being reported, and menstrual abnormalities have been reported as a side effect in women. However, it is still unclear whether the COVID-19 vaccine has detrimental effects on the female reproductive system. Therefore, we investigated the effect of excessive immune response on reproductive function by administering Lipopolysaccharides (LPS) instead of the COVID-19 vaccine. The immune response in mice was induced by injection of LPS. Mice injected with saline 5 times were used as a control group, and mice injected with LPS 5 times were used as an experimental group. Repeated administration of LPS significantly reduced the number of corpus luteum (CL). On the other hand, the injection of LPS did not affect the development of follicles leading before the CL. The expression of the apoptosis-related genes Fas and Fas-L increased in the experimental group. In addition, the expression of the inflammation-related genes increased in the experimental group. In this study, we confirmed that LPS had detrimental effects on the uterus and ovaries in mice. These results suggest that injection of LPS can cause immune reactions within the uterus and ovaries and cause hormonal changes, which can have adverse effects such as abnormal operation or bleeding of the menstrual cycle. These results are expected to help determine the cause of decreased reproductive function, infertility, or physiological disorders caused by the COVID-19 vaccine.