• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.39-46
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• 1994

This experiment was carried out to develop an in vitro culture system for rabbit embryos. The zygotes or 2-cell embryos were collected from the oviducts of the superovulated and mated does with D-PBS/10% FCS at 24 hours after hCG injection. The in vitro developmental rate of blastocyst formation and the number of nuclei in the embryos were examined under the following treatments; 1) TCM-199 with 10% FCS, 2) EBSS with 10% FCS, 3) rabbit vitreous humor(VH), 4) TCM-199 with 10% FCS＋BOEC, 5) TCM-199 with 10% FCS＋ROEC, 6) EBSS with 10% FCS＋BOEC and 7) EBSS with 10% FCS＋ROEC. For a comparative study of in vivo and in vitro development, the fresh blastocysts, which were developed in vivo for 96 hours after hCG injection, were collected from the uterus and their numbers of nuclei were counted. 1. The zygotes or 2-cell embryos developed to the blastocyst stage in TCM-199, EBSS and VH at the rates of 93, 92 and 89%, respectively. 2. The higher developmental rates 95~98% of blastocyst formation was achieved when the embryos were co-cultured with a monolayer of bovine or rabbit oviductal epithelial cells in TCM-199 or EBSS. No significant difference in developmental rates was shown between bovine and rabbit oviductal epithelial cells. 3. In a comparative study of in vivo and in vitro development, the total numbers of nuclei were significantly less in the in vitro cultured embryos(104~224) than the in vivo developed embryos(1, 0090 at 96 hours after hCG injectin. 4. The mean cell cycle numbers in the embryos cultured for 72 hours in TCM-199 with 10% FCS, EBSS with 10% FCS, TCM-199 with 10% FCS＋BOEC, TCM-199 with 10% FCS＋ROEC, EBSS with 10% FCS＋BOEC and in vivo was 7.38, 6.63, 7.76, 7.69, 7.01 and 9.92, respectively. From these results, it can be suggested the optimal culture system for in vitro culture of rabbit embryos is a co-culture system with bovine or rabbit oviductal epithelial cells in TCM-199 with 10% FCS. Considering the significant reduction in total numbers of nuclei in the in vitro cultured embryos, the advanced research on development of in vitro culture system for rabbit embryos is expected.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.63-70
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• 1994

Thirty ewes received typical trauma to their oviducts and uterine horns from surgical embryo collection procedures. Ten percent Dexamethasone was used as an irrigant on the exposed abdominal tissue prior to closing the incision. The treatment group received 17mg colchicine Om! lewe) and the control group was administered a 1.0ml placebo(PSS). Fifteen ewes that were initially treated with 17mg /im colchicine showed acute colchicine toxicity within 2-5 days after initial treatment and were removed from the study. Due to acute colchicine toxicity at 17mg, the colchicine level was lowered to 8, 4 and 2mg(4 ewes/group). Treatments consisted of daily injections of colchicine. One ewe in the 8mg group developed toxicity on day 5. Therefore, ewes were then administered colchicine every other day from day 6 to day 14 postsurgeryat 4 and 2 mg. the second laparotomy was performed 9 weeks after first treatment. Following second laparotomy, the treatment group(n=5) received 4 mg colchicine every day for 14 days and there was no clinical symptoms of colchicine toxicity. The third laparotomy was performed by the same operators 5 weeks after final treatment and the adhesions scored. Adhesion grading was based on a scale of 0-4, with 4 being the most severe. The results of adhesion grading(> 3) at second laparotomy were not significantly different(P>0.05)between the two groups. Adhesion formation observed at third laparotomy showed a reduced, but not significant reduction (P>0.05) in the colchicine-treated ewes when compared with the controls. Ten ewes(5 control and 5 treatment)were examined cytogenetically by bone marrow analysis five days post-treatment. There was no difference(P>0.05)in the incidence of numerical or structural aberrations between the two groups.

• Korean Journal of Pharmacognosy
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• v.28 no.3
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• pp.104-111
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• 1997

The traditional herbal medicine, Jackyakgamcho-tang(JGT), was reported to decrease serum testosterone levels and make pregnancy possibel in anovulatory woman and rat. JGT contains Paeoniae Radix(PR) and Glycyrrhizae Radix(GR) in equal amount. This study was designed to investigate the effect of JGT and its components(PR, GR, paeoniflorin and glycyrrhizin) on uterine and ovarian responses, follicular development, and estrogen secretion in the immature rat. The samples(water extracts of JGT, PR, GR; pure compound of paeoniflorin and glycyrrhizin) were administered orally to rats from the 21th day of age to the 28th or 30th days of age for 7 or 9 days. JGT(400mg/kg) and PR(100mg/kg, 200mg/kg) treatments significantly increased serum estradiol above levels in control rats, but both GR and glycyrrhizin had no effect on this parameter. Gross observation and histological analysis revealed that an increased number of growing follicules was observed in the ovaries of JGT and PR treated rat. However the lutenized follicles and ova present in the oviducts were not observed in all rats except one treated with estrogen as a positive control. These results indicate that JGT stimulates the estrogen production and follicular maturation in the immature rat and PR is the main component to induce such reaction.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.276-286
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• 1999

In the present study, to understand how gonadotropin-releasing hormone (GnRH) affects ovarian functions in superovulated rats, we examined the effects of GnRH agonist on the ovulatory response, the morphological normality and nuclear maturation of ovulated oocytes, the ovarian weight, the ovarian histology, and the circulating steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in immature rats pretreated with 30IU pregnant mare serum gonadotropin (PMSG) and supplemented with 10IU human chorionic gonadotropin(hCG). GnRH agonist was intravenously injected via jugular vein catheter every 20min for 4hrs in early follicular phase (from 6hr after PMSG) of superovulated rats. In addition, GnRH antagonist, Antide, was intravenously injected in combination with GnRH agonist to verify the effects of GnRH agonist on ovarian functions. All animals were sacrificed at 72hr after PMSG administration. The administration with GnRH agonist in early follicular phase of superovulated rats caused inhibition of ovulatory response, increased the proportion of abnormal appearing oocytes(especially, in the rats of the group treated with 500ng GnRH agonist), decreased ovarian weight and promote follicular atresia, compared to those from the rats of control regimen that were not treated with GnRH agonist. In addition, the treatment with GnRH agonist in the superovulated rat distinctly decreased serum steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in preovulatory phase. On the other hand, the inhibitory effects of GnRH agonist treatment in superovulation-pretreated rats on ovarian functions were totally reversed by the combination with GnRH antagonist, Antide. The nuclear maturation of oocytes recovered from the oviducts in immature rats treated with GnRH agonist and/or GnRH antagonist was characterized by prematurity and asynchronization in early follicular phase, which was similar to control group. The overall results of this study indicate that GnRH agonist disturbs directly ovarian function in early follicular phase of superovulated immature rats in terms of ovulatory response and morphological normality of ovulated oocytes. This concept has been further evidenced by the findings of a great decrease in ovarian weight, a marked increase in follicular and a distinct decrease circulating steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in GnRH agonist treatment regimen in early follicular phase.

• Development and Reproduction
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• v.3 no.1
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• pp.59-67
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• 1999

To investigate the role of interleukin-l$\beta$ (IL-1$\beta$) in the embryonic development, in vivo and in vitro expression patterns of IL-1$\beta$ gene in the preimplantation mouse embryos were examined by RT-PCR, and the effects of explanted mouse ovi-duct and uterine epithelial cells on the expression of IL-1$\beta$ gene in the pleimplantation mouse embryos were examined by co-culture. IL-1$\beta$ mRNA was detected in the embryos from 4-cell stage to blastocyst stage in vivo and from morula stage to hatching blastocyst stage in vitro. This transcript was not detected from the GV stage to late 2-cell stage in vivo, and not at the 4-cell and 8-cell stages in vitro. For the co-culture of late 2-cell embryos with the explanted mouse oviduct and uterine epithelial cells, oviducts and uterine epithelial cells were isolated at 48 hour alter the hCG injection. The explanted oviduct and uterine epithelial cells in co-culture groups facilitated the IL-1$\beta$ gene expression of the mouse embryos in comparison with the control. Taken together these results suggest that the presence of IL-1$\beta$ plays an important role in preimplantation embryonic development. In addition, the up-regulation of IL-1$\beta$ gene expression by the explanted oviduct and uterine epithelial cells demonstrates that embryonic expression of IL-l$\beta$ gene may be regulated by the interaction with oviductal and uterine factor (s).

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.259-267
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• 1997

To improve the efficiency of production of cloned embryos and animals by nuclear transplantation in the rabbit, the effect of cell cycle of donor nuclei and type of recipient cytoplasm on the in vitro developmental potential and production efficiency of offspring was determined. The embryos of 16-cell stage were collected from the mated does at 48h post-hCG injection and they were synchronized to G$_1$ phase of 32-cell stage. The oocytes collected at 14h post-hCG injection were freed from cumulus cells and then enucleated. One group of the enucleated cytoplasms was activated by electrical stimulation prior to injection of donor nucleus, and the other group was not pre-activated. The separated G$_1$phase blastomeres of 32-cell stage embryos were injected into the perivitelline space of recipient cytoplasms. After culture for 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation and the fused nuclear transplant embryos were co-cultured for 120h and the nuclear transplant embryos developed to blastocyst stage were stained with Hoechst 33342 dye and their blastomeres were counted. Some of the nuclear transplant embryos developed in vitro to 2- to 4-cell stage were transferred into the oviducts of synchronized recipient does. The electrofusion rate was similar between the types of donor nuclei and recipient cytoplasms used. However, the nuclear transplant embryos using G$_1$ phase donor nuclei were developed to blastocyst at higher rate(60.3%) than those using S phase ones(24.7%). Also, when non-preactivated oocytes were used as recipient cytplasms, the develop-mental rates of nuclear transplant embryos to blastocysts were significantly(P< 0.05) higher(57.1%) than those using preactivated ones(20.8%). The cell counts of nuclear transplant embryos developed to blastosyst stage were increased signficantly(P<0.05) more in the non-preactivated recipient cytoplasm(163.7 cells), as compared whit the preactivated recipient cytoplasm(85.4 cells), A total of 49 nuclear transplant embryos were tranferrid into 5 recipient does, of which two offsprings were produced from a foster mother 31 days after embryo transfer. these results showed that the blastomeres of G1 phase and non-preactivated oocytes might be utillzed efficiently as donor nuclei and recipient cytoplasms in the nuclear transplant procedure, thought the offspring production remained still low.

• Journal of Veterinary Clinics
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• v.12 no.1
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• pp.877-886
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• 1995

The recycling nuclear transplantation(NT) technique has the powerful potential of producing a large number of genetically identical embryos and offsprings from one embryo. Multiple generational cloning by this technique utilizes the NT embryo itself as the donor for the next generation of cloning. In this experiment, we have produced the third generational cloned embryos by recycling NT. Further we examined comparatively the electrofusion rate and in vitro developmental potential in the cloned embryos of the first second and third generations. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulberco's phosphate buffered saline containing 10 % fetal calf serum(FCS) at 47 hours after hCG injection. In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gl/S transition of 32-cell stage. The first and second generation NT embryos developed to 16-cell were used as donor nuclei for second and third generation. The recipient cytoplasms were utilized the oocytes collected at 14 hours after hCG injection, following revoming the nucleus and the first polar body by micromanipulation. The separated blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were fused by electrical stimulation. The electrofusion rate was seen to be 78.0, 88.0 and 90.3 % in the first second and third generation NT rabbit embryos, respectively. The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10 % FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. The in vitro developmental potential to blastocyst stage was significantly(P<0.05) decreased in the third(7.2 %) generation NT embryos compared to the first(53.1 %) and second(16.1 %) generation NT embryos. Following in vitro development to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The mean blastomere numbers and cell cycle numbers of NT embryos during the culture period were significantly(p<0.05) decreased in the second(93.9 cells and 6.55 cylces) and third(81.5 cells and 1.35 cylces) generation, compared to the first(189.9 cells and 7.55 cylces) generation.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.113-119
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• 2004

The purpose of the present study was to examine whether collection time affects results of oocyte recovery from superovulated goats. Fiftyty-one mature Korean native goats, maintained in a pen under natural day length and fed hay ad libitum, were pretreated with progestagen impregnated CIDR for 10 days and then the goats were divided into two groups. One group of the goats received a single intramuscular injection of 1,000 IU PMSG on Day 8 of CIDR insertion. The other group of the goats received twice daily intramuscular injections of a total of 70 mg FSH for 3 days from Day 8 of CIDR. All the gonadotropin treated goats were injected with 10 mg $PGF_{2\alpha}$ on Day 8 and 400 IU hCG in the afternoon on Day 10. For oocyte recovery, donor goats were fasted 24 h before operation. Anesthesia was induced by intravenous injection of 2% xylazine(0.2 mg/kg body weight) and ketamin(11 mg/kg body weight). In vivo oocytes were recovered by follicle aspiration or oviduct flushing at 29 to 34, 35 to 40 and 41 to 50 h after hCG injection through mid-ventral incision. There was no significant difference in the mean number of CL and oocytes recovered. Oocyte collection at 29 to 40 h after hCG increased(P<0.05) the recovery rate of ovulated oocytes in oviducts compared to 41 to 50 h. The same results were also observed in the recovery of follicular oocytes. Oocyte grade was not affected by collection time. When oocytes were collected from follicular oocytes at 41 to 50 h after hCG, the recovery rate of Grade II oocytes was the lowest(P<0.05). From these results, it is suggested that oocyte recovery at 35 to 40 h after hCG will be successful for further use.

• Korean Journal of Animal Reproduction
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• v.19 no.3
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• pp.227-234
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• 1995

This study was carried out to investigate the effects according to the time course of glucose exposure on the development of one-cell embryos beyond morula in CR$_laa$ medium. One-cell zygotes from B6CBA F$_1$ mice were recovered at 24 ~ 25h after hCG and cumulus cells were removed with 0.1% hyaluronidase. The embryos were pooled and subsequently divided into each groups and cultured in CR$_laa$ at 37$^{\circ}C$ in 5% CO$_2$ in aIr. The embryos were either, placed in CR$_laa$ containing various concentration (5.5, 16.5, 27.5 and 38.5 mM) of glucose for 1 min. and subsequently returned to the fresh culture medium (without glucose), or were transferred to the same media containing glucose at 72 h post hCG. The results obtained in these experiments were summarized as follows: 1. The development rates of zygotes, recovered from the oviducts in M2 and cultured in CR$_laa$ with 3mg/Im FAF-BSA, to expanded blastocysts (25.7%) and hatching bIastocysts (17.6%) were significantly higher than those of zygotes recovered in TL Hepes (0% and 0%, respectively). 2. The development rates of one-cell embryos exposed to 27.5 mM glucose at 72 h post hCG for 1 min, were 68.8% (CR$_1$+BSA) a and 77.1% (CR$_1$+FBS) of expanded blastocyst stage, but there were no significant differences between the embryos exposed for 1 min. or transferred at 72 h. 3. Regardless of glucose concentration (5.5, 16.5, 27.5 & 38.5mM), 45.7~61.5% of embryos developed to the blastocyst stage. There were no significant differences between any of the treatments on the devel-opment of one-cell embryos. Therefore, the detrimental effect of highly concentration was not appeared.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.139-146
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• 1997

This experiment was carried out to evaluate the effect of mouse early embryonic development in vitro by co-culture with bovine and porcine oviductal epithelial cells(BOEC and POEC). The 2-cell embryos were collected from the oviducts of the superovulated and mated does with D-PBS/15% FCS at 48 hours after hCG injection. The in vitro developmental rate of blastocyst formation and the number of nuclei in the embryos were examined. For a comparative study of in vi패 and in vitro development, the fresh blastocyst which developed in vivo for 120 hours after hCG injection was collected from the uterus, and their numbers of nuclei were also counted. The higher developmental rates of blastocyst formation was a, pp.ared from 91% to 97% when the embryos were co-cultured with a monolayer of bovine or porcine oviductal epithelial cells in TCM 199 or Ham's F-10 and MediCult IVF media. No significant difference in developmental rates was shown between bovine and porcine oviductal eptithelial cells. The number of nuclei in the embryos cultured for 72 hours under each conditions was significantly reduced it than blastocyst in vitro conditions. The number of nuclei in embryos cultured in TCM 199, Ham's F-10 and Medicult IVF medium were counted 68.1$\pm$6.00, 67.3$\pm$4.49, 66.4$\pm$5.64, and 94.3$\pm$8.61, 92.5$\pm$7.60, 92.1$\pm$6.10 with BOEC and 93.3$\pm$5.80, 92.9$\pm$6.53, 92.3$\pm$7.35 with POEC coculture, respectively. These numbers were lowered than 107.2$\pm$7.43 in vivo conditions. In conclusions, the coculture between the mouse early embryos, and oviductal epithelial cells of BOEC and POEC give to improve the developmental and hatching rates of blastocyst but in vivo culture systems for the growth of nuclei were ineligible than in vitro conditions.