• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.265-274
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• 2009

Objective: MicroRNAs (miR) are known to repress target genes at post-transcriptional level and play important roles in development and maturation of cell. However, the expression profiles of miR during ovarian follicle maturation have not been fully elucidated. Here, we designed this study to investigate the expression profiles of miR in oocytes and granulose cells (G-cells) after in vitro culture according to gonadotropins and adding hCG. Methods: Ovaries from 12-day-old mice (C57BL6) were removed and preantral follicles were isolated and cultured in $20\;{\mu}L$-drop of culture media with supplementation of either rFSH, rLH, or rFSH+rLH. After their full maturation, follicles were incubated with rhCG and rEGF. RNA was isolated from oocytes and G-cells, and real-time PCR were performed with primers of miR known to be expressed in the mouse ovary (mmu-miR-16, -miR-27a, -miR-126, -miR-721). Results: FSH+LH group showed the highest ovulation and MII rates among gonadotropin groups. The profiles of miRs in oocytes and G-cells differed according to gonadotropin groups and adding hCG. The profiles of miRs showed divergent changes between oocytes and G-cells. Conclusion: miR expression profiles are altered by gonadotropins and supplementation of hCG during in vitro maturation of murine follicles. Target gene study must be necessary to validate these findings.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.93-100
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• 2001

This study was conducted to evaluate the nuclear development of preantral follicle oocytes in dog following collecting from different estrus ovaries and oocyte diameter. To do this, ovaries were collected from Sunchon livestock station by ovarioectomy and then transported to laboratory in 3$0^{\circ}C$ saline within 2 h. All of the ovaries were washed three times with saline supplemented with 100 IU Penicillin and 100 $\mu\textrm{g}$/$m\ell$ Streptomycin and then sliced with blade in 100 mm dish. All of the oocytes collected were classified the oocyte size such as over 110 ${\mu}{\textrm}{m}$ or under 110 ${\mu}{\textrm}{m}$ and the estrus status. To induce the nuclear development, oocytes were cultured in TCM199 $\alpha$-MEM supplemented with 10% FCS, 0.1 $\mu\textrm{g}$/$m\ell$ sodium pyruvate, 100 ng/$m\ell$ FSH, 100 ng/$m\ell$ EGF, 1% ITS, 100 IU/$m\ell$ penicillin, 100 $\mu\textrm{g}$/$m\ell$ streptomycin at 38.5$^{\circ}C$, 5% $CO_2$ incubator for 72 h. After culture, all of the oocytes were stained in 1% orcein following fixed in 45% Acetic acid for 48 h. The oocyte recovery rates of over 110 ${\mu}{\textrm}{m}$ from estrus ovary (63.6%) were significantly higher rather than that in anestrus status (51.5%). Oocyte recovery rate per ovary of over 110 ${\mu}{\textrm}{m}$ in estrus status ovary (22.6/63.8%) was also significantly higher rather than that in anestrus status ovary (8.2/51.6%). Nuclear development to MI of over 110 ${\mu}{\textrm}{m}$ in estrus ovary (24.3%) was significantly higher rather than those in under 110 ${\mu}{\textrm}{m}$ or over and under 110 ${\mu}{\textrm}{m}$ in anestrus (2.5, 6.8 and 0.0%), respectively (P ＜ 0.05). Nuclear development to AT and MII of over 110 ${\mu}{\textrm}{m}$ in estrus was more developed in other groups. Nuclear development to MI in TCM199 (21.8%) was significantly higher than in $\alpha$-MEM (10.0%). Altho $\mu\textrm{g}$h the development rate to AT was significantly different between TCM199 (7.3%) and $\alpha$-MEM (1.1%), but to MII was not different between TCM199 (0.9%) and $\alpha$-MEM (1.1%). The results indicated that over 110 ${\mu}{\textrm}{m}$ oocytes was could be recovery from estrus status ovary, bigger oocytes were more developed to MI, AT or MII in TCM199.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.71-78
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• 1997

This study was designed to investigate the number of the growing and mature follicles following gonadotrophin treatments for superovulation in mature rats. Eighteen mature rats (Sprague-Duwely, initially 190~230gm) were randomly alloted into 3 groups. One group was control group, another FSH-treated group was injected intramuscularly with 0.5 units of follicular stimulating hormone (FSH) / rat, and third PMS and HCG-treated group was intramuscularly injected with 20~25IU of pregnant mare serum (PMS) / rat and then at the 48 hrs later, with 20~25IU of human chorionic gonadotrophin (HCG) / rat. The uteri and ovaries of rats were collected and then were observed grossly and serial sections of paraffin embedding ovaries were stained with H-E. Number of ovarian follicles by following 3 grades of large, middle and small follicles from secondary and tertiary follicles were investigated by LM photography of preparations. Small follicles were classified as secondary follicles of preantral follicles with more than 2 layers of granulosa cells surrounding the oocyte and middle follicles were classified as secondary follicles with early signs of antral cavity or with more than one small cavity on either side of the oocytes and large follicles were classified as tertiary follicles with a single medium sized antral cavity or large well-formed antral cavity. In gross findings, the uteri were slightly swelling in FSH-treated group and markedly swelling or filled with fluid in the uterine lumen in PMS and HCG-treated group. In histological findings, the shape and size of the follicles were diverse in middle and large follicles of FSH-treated group and PMS and HCG-treated group, and proportion of atretic follicles was increased in FSH-treated group and PMS and HCG-treated group than those in control group. The uteri of FSH-treated group and PMS and HCG-treated group were hypertropied or filled with fluid in the lumens and walls of uteri. The wall tissue layers were flattened and their blood and lymph vessels were dilated. The mean number of follicle per ovary in control group were appeared to be $17.1{\pm}5.6$($14.0%{\pm}4.6%$), $37.8{\pm}9.1$($30.9{\pm}7.4%$) and $67.6{\pm}30.1$($55.2{\pm}24.6%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $122.5{\pm}40.0$. The mean number of follicle per ovary in FSH-treated group were appeared to be $22.8{\pm}7.0$($17.4%{\pm}5.3%$), $43.4{\pm}6.6$($33.2{\pm}5.1%$) and $64.5{\pm}13.0$($49.3{\pm}9.9%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $130.7{\pm}16.6$. The mean number of follicle per ovary in PMS and HCG-treated group were appeared to be $29.7{\pm}11.0$($16.3%{\pm}6.0%$), $61.9{\pm}17.2$($33.9{\pm}9.4%$) and $91.1{\pm}28.2$($49.9{\pm}15.4%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $182.6{\pm}32.7$. The above findings reveal that large follicles were increased 29.8% in FSH-treated group and 73.7% in PMS and HCG-treated group than those in control group and in histologic findings, proportion of atretic follicles were more increased in ovaries with more number of more developing follicles.

• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.265-274
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• 1997

The purpose of this study was attempted to investigate the a, pp.arences of healthy or artretic follicles in ovaries following repeats of pregnant mare serum gonadotropin(PMSG) treatments for superovulation in nulliparous rats. Thirty two rats(Sprague-Dawely, about 200-250 gm) were randomized into 4 groups. Control group rats were sacrified at estrus phase confirmed by vaginal smear. PMSG-treated group 1 rats, PMSG-treated group 2 rats and PMSG-treated group 3 rats were sacrified at 48 hrs after injection once with PMSG 25 IU, after 2 repeated injection by a week interval, and 3 repeated injection, respectively. The ovaires of rats were removed and then sections by paraffin embedding were stained with H-E or immunohistochemical staining using proliferating cell nuclear antigen monoclonal antibody (PCNA m Ab) and apoptotic kit. The criteria of follicle classification was based as small follicles with preantral follicles with 2~4 layers of granulosa cells surrounding the oocyte, as secondary follicles with more than 5 layers of granulosa cells and early signs of antral cavity or with small clefts on either side of the oocytes, and as tirtiary follicles with a single medium sized antral cavity or large well-formed antral cavity, respectively. The proportions of atretic follicles from small and middle follicles in immunohistochemical staining using PCNA m Ab were 17.9% and 21.3% in control group, 15.5% and 23.5% in PMSG-treated group 1, 24.3% and 26.7% in PMSG-treated group 2, 18.1% and 30.2% in PMSG-treated group 3, respectively. Groups with atretic follicles of higher proportion were ordered as PMSG-treated group 3, PMSG-treated group 2, PMSG-treated group 1 and control group. The proportions of positive cells in small, middle and large follicles were 31.1%, 33.5% and 28.5% respectively. The follicles with positive cells of higher proportion were ordered middle, small and large follicles. In immunohischemical staining using apoptotic kits, small follicles in all 4 groups did not contain positive cells, and proportions of atretic follicles from middle and large follicles were 24.9, 30.7, 33.8 and 40.1% in control, PMSG-treated gruop 1, PMSG-treated group 2 and PMSG-treated group 3, respectively. These results suggested that repeats of PMSG treatment increased proportion of atretic follicles in ovaries, and middle follicles are more quickly developing than small or large follicles.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.125-130
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• 2001

This study was performed to report a direct dose dependent stimulatory effect of the Flavonoid(F) on basal testosterone secretion and a dose dependent effect on LH induced testosterone production by Leydig cell of matured rats in vitro culture. F was obtained kom the Rhus vernicifua through aceton extraction and silica gel adsorption column chromatography. Leydig cells (1$\times$10$^{6}$ cells/well) from 12 weeks old rats were incubated with or without F(0, 20, 40, 80, 160 ng) or insulin-like growth factor-I(IGF-I) in the presence or absence of LH(10, 100ng). 1. The maximal stimulatory concentrations of testosterone in culture media were showed at 24hr of culture. but these testosterone level were decreased at 36 hr of culture. 2. Flavonoid(80ng) were significantly(P ＜ 0.05) increased testosterone production compared with control groups for 12 hr culture. 3. Testosterone secretion by Leydig cells stimulated with LH(10, 100ng) for 6 hr and 12hr culture compared with 3 hr culture. 4. LH 10 ng augmented testosterone were increased by addition of F 40 ng for 12 hr culture. 5. F(0 and 40 ng) also enhanced LH 10 ng stimulated testosterone for 3 hr Leydig cells culture. 6. Addition of IGF-I 100 ng to the culture medium for 6 hr were increased the concentration of testosterone by Leydig cells stimulated with 100 ng LH. These results indicate that Flavonoid has a direct stimulatory effect on basal testosterone secretion in rat Leydig cells, and also modulates LH mediated testosterone. Therefore, Flavonoid may act as a modulator on gonadal development or gonadal steroidogenesis in direct or indirect.