• Animal cells and systems
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• 제11권1호
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• pp.1-8
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• 2007

Recently, we have shown that some endocrine disruptors, heavy metals, organotins and azoles suppressed steroidogenic enzymes such as P450 side-chain cleavage enzyme (P450scc) and aromatase in bullfrog ovarian follicles. In the present study, by using an amphibian ovarian follicle culture system, we examined the effects of these endocrine disruptors on maturation and ovulation of oocytes from Rana dybowskii in vitro. Ovarian fragments or isolated follicles were cultured for 24 h in a medium containing frog pituitary homogenate (FPH) or progesterone ($P_{4}$) with or without endocrine disruptors, and oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation were examined. Among the organotins, tributyltin (TBT) strongly inhibited both FPH-and $P_{4}-induced$ oocyte maturation ($ED_{50}$:0.6 and 0.7 ${\mu}M$, respectively); however, tetrabutyltin (TTBT) and dibutyltin (DBT) showed only partial suppression, while monobutyltin (MBT) showed no inhibitory effect. All of the organotins suppressed $P_{4}-induced$ oocyte ovulation very effectively at a low concentration, and TBT and DBT exerted an inhibitory effect on FPH-induced ovulation. Among the heavy metals, mercury (Hg), cadmium (Cd) and cobalt (Co) were very effective in inhibiting FPH-induced oocyte maturation and ovulation, while lead (Pb), arsenite (As) and zinc (Zn) were less effective. However, all of the heavy metals suppressed FPH-induced oocyte ovulation at a high dose ($100{\mu}M$). Among the azoles, itraconazole (ICZ), ketoconazole (KCZ) and clotrimazole (CTZ) effectively inhibited FPH-induced oocyte maturation and ovulation, while econazole (ECZ), miconazole (MCZ) and fluconazole (FCZ) were considerably less effective. These results demonstrated that the abovementioned endocrine disruptors exhibited differential effects on oocyte maturation and ovulation in amphibian follicles and that the frog ovarian culture system could be used as an effective experimental tool to screen and evaluate the toxicity of various endocrine disruptors in vitro.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.29-32
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• 1992

The effects of prostaglandins (PG) and indomethacin, a PG synthesis inhibitor, on ovulation in the perfused fowl ovary were studied. Laying hens were killed by cutting the jugular vein 18-19 h before expected ovulation of the second follicle of a clutch sequence. The cannulated ovary was dissected free and connected with a recycling perfusion apparatus. Agents to be studied for their effects on ovulation were added to the perfusion fluid. $PGF_{2{\alpha}}$ at 0.1 and 1 mg/l induced ovulation, with a success rate of 25% and 30%, respectively. The same doses of $PGE_2$ were effective at 60% and 63%, respectively. Indomethacin partially blocked gonadotrophin-induced ovulation. It is suggested that PGs may play a supportive role in the process of follicular rupture in the domestic fowl.

• Animal cells and systems
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• 제3권4호
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• pp.385-391
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• 1999

Changes in the levels of prostaglandian F$_{2a}$ (PGF$_{2a}$) and E$_2$ (PGE$_2$) in culture medium during in vitro ovulation of Rana dybowskii follicles were examined. The ovulation was induced by frog pituitary homogenate (FPH) or TPA (12-O-tetradecanoylphorbol-13-acetate, a protein kinase activator) and the levels of PGs were measured by radioimmunoassay. When the ovarian follicles were cultured, only a few oocytes were ovulated by 12 h, but half of them were ovulated by 24 h in response to FPH, whereas around 30% of oocytes were ovulated by 12 h and maximum ovulation (around 50%) occurred by 24 h in response to TPA. Without any stimulation (control), no ovulation occurred. TPA elevated the level of PGF$_{2a}$ to high levels when compared to control (basal levels), but the increase by FPH was less evident. Likewise, the levels of PGE$_2$ increased markedly in response to TPA, but rather decreased by FPH treatment. Interestingly, PGF$_{2a}$ induced ovulation but PGE$_2$ suppressed FPH- or PGF$_{2a}$-induced oocyte ovulation. Basal levels of PGs Increased steadily during culture. When theca/epithelium (THEP) layer and granulosa cell-enclosed oocytes (GCEOs) were separated by microdissection and cultured independently, higher levels of both PGs were secreted by THEP than by GCEOS. Synthesis of PGs by follicle or follicular components was strongly suppressed by exogenous cAMP or indomethacin. These results suggest that: 1) PGF$_{2a}$ plays an important role in Rana ovulation, 2) protein kinase C is involved in PGs production, and 3) thecal epithelium layer is responsible for the PGs production in Rana.

• 한국동물학회지
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• 제39권3호
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• pp.266-272
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• 1996

봄에 채집한 참개구리의 난소조각 배양계를 사용하여 난자의 배란과정에 프로스타글란딘과 protein kinase C(PKC)가 관여하는 지를 조사하였다. 난소조각을 배양하면서 뇌하수체추출물(FPH) 혹은PKC의 활성제인 12-O-tetradecanoyl phorbol-13-acetate (TPA)를 처리한 후 배란율과 프로스타글란딘의 생상량을 방사면역측정법으로 조사한 결과 농도에 의존하여 난자의 배란이 유도 되었으며 프로스타글란딘의 생성이 촉진되었다. FPH와 TPA에 의한 배란과 프로스타글란딘 생성은, 4월 보다는 5월에 채집한 개구리에서 훨씬 더 효과적이었다. FPH처리는 프로스타글란딘과 함께 progestreone의 생성을 촉진하였으나 TPA는 progestreone의 생성을 촉진하지는 못하였다. FPH와 TPA에 의한 배란과ㅣ 프로스타글라딘 생성 억제제인 indomethacin에 의해서는 난자의 배랑니 억제되지는 않았다. 이러한 결과들은 참개구리 난자의 배란 과정에 PKC의 활성화가 중요한 역할을 하며, 프로스타글라딘의 생성이 매개할 것으로 생각된다.

• Clinical and Experimental Reproductive Medicine
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• 제15권2호
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• pp.129-133
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• 1988

Combined (intra and extrauterine) pregnancy refers to impregnations of two different ova at intrauterine and extrauterine sites simultaneously or within a short time interval each other. It is a rare clinical entity and freqently missed in early diagnosis in most instances. Its incidence rate is about 1 in 30,000 pregnancies and the incidence was rised in cases of using ovulation induced agents. The diagnostic rate is less than 10% at early process of the disease. We experienced a case of intrauterine and left tubal pregnancy as combined pregnaney in ovulation cycle which had been induced by clomiphene citrate and now present it with brief review of related leteratures.

• 한국수정란이식학회지
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• 제29권2호
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• pp.177-182
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• 2014

Feline ovulation time after LH surge have not been defined because its LH surge is occurred by several times of coital vaginal induction and cat has relatively longer time between LH surge and ovulation compared with other mammalian species. This study was performed to investigate the feline ovulation time after LH surge that was induced by hCG injection for superovulation with PMSG. For superovulation, all cats were received an initial injection of PMSG (200 IU, i.m.) followed 80 hrs later with an injection of hCG (200 IU, i.m.). And then, sampling of both ovaries was surgically performed at each 6 different times (10, 18, 22, 26, 29, and 32 hrs) after hCG injection. Cumulus-oocyte-complexes (COCs) were collected from 2 sides of oviducts and ovaries were fixed for ovarian histology. Total 38 COCs were collected only at hCG 32 hrs and no COCs were shown at earlier 5 times. However, in the ovarian histology, corpus haemorrhagicum or corpus luteum was not shown in all groups including ovary at hCG 32 hrs that COCs were collected. In conclusion, it was suggested that feline ovulation was occurred at 29~32 hrs after LH surge and taken relatively long time for CL formation after ovulation.

• 한국양식학회지
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• 제12권3호
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• pp.197-204
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• 1999

Successful produciton of seedlings for marine fish species are highly influenced by the aquisiton of sufficient number of good-quality eggs on required time. human chorionic gonadotropin has been used to induce successful ovulation for the purpose. Rabbitfish, siganus canaliculatus, is inhabited along the coast of Cheju Province and treated valuably for raw fish and fish roasted with seasoning. Female wild-captured rabbitfish (314 to 279 g in body weigth) were injected into intraperitoneal space with human chorionic gonadotropin (HCG) of 5,00,1,000, and 1,500 IU/kg body weight during spawning season of July 14 (trial 1), and July 27 (trial 2). Test fish in trial 1 were injected two times, first on July 14 and second on July 21 with one weekinterval because of no ovulation symptoms, but just one time in trial 2. All females injected both 1,000 and 1,500 IU/kg body weight ovulated in all trials. Among 500 IU/kg injection treatments, just one female ovulated in trial 1 showing 25% of ovulation rate, but none ovulated in trial 2. Ovulation was not occurred in control goups during test period. Time to reach ovulation after injection was 172 to 270 hours in trial 1 and 77 to 132 hours in trial 2, showing shorter as spawning season approached. Generally, ovulation of smaller females were late than that of larger ones. Gonadosomatic index (GSI) and pseudo-gonadosomatic index (Pseudo-GSI) were ranged 22 to 33% and 19 to 28%, respectively. One female spawned 406,200 to 1,032,000 eggs, and obtainable eggs per 100g of body weight were calculated by 130,000 to 190,000. Spawning rates were comparatively high by 96.0 to 98.4%. Rates to reach embryo-formation and hatching were higher in 500 high by 96.0 to 98.4%. Rates to reach embryo-formation and hatching were higher in 500 and 1,000 IU/kg treatments than in 1,500 IU/kg treatment. The result of present study demontrates that HCG treatment during spawning season could become very useful for ovulation of rabbitfish and the suitable dosage was suggested as 1,000 IU/kg of body weight.

• 한국수산과학회지
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• 제50권1호
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• pp.41-47
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• 2017

Perhaps the most common type of reproductive dysfunction in captive fish is failure of females to undergo final oocyte maturation and thus to ovulate and spawn. The success of aquaculture could therefore be improved by developing techniques to enhance natural spawning, artificial maturation, and/or to induce ovulation in farmed fish. This study aimed to investigate the effects of prostaglandin $E_2$ ($PGE_2$) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) on in vitro oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation in the marine fish Chasmichthys dolichognathus. Post-vitellogenic follicles (0.80-0.94 mm diameter oocytes) were incubated with $PGE_2$ or $PGF_{2{\alpha}}$ at concentrations of 5, 50, or 500 ng/mL for 24 hours. A significant increase in GVBD was seen in 0.84 mm and 0.94 mm oocytes incubated with 50 ng/mL $PGE_2$ compared with the control. There was no significant increase in GVBD in any of the other experimental conditions (5 or 500 ng/mL $PGE_2$ or 5, 50, or 500 ng/mL $PGF_{2{\alpha}}$). Neither of the prostaglandins induced ovulation at the concentrations tested.These results suggest that GVBD was induced by incubation with 50 ng/mL $PGE_2$.

• 한국양식학회지
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• 제3권1호
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• pp.25-30
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• 1990

차넬메기(Ictalurus punctatus)는 전 세계적으로 중요한 양식어종이나 우리나라의 경우 대량산란이 이루어지지 않아 아직 양식 대상종으로 각광받지 못하고 있다. 본 연구는 차넬메기를 염색체공학 기법을 이용, 배수체를 생산하기 위한 일환으로 온도자극과 호르몬처리를 통해 산란을 유도하였다. 그 결과 처리하지 않은 군은 산란하지 않은 반면 온도자극시, $24^{\circ}C$로 부터 $30^{\circ}C$로 $6^{\circ}C$를 증가시킨 군이 $24^{\circ}C$ 부터 $27^{\circ}C$까지 온도를 증가시킨 군보다 약 4배 정도의 높은 산란유도율을 보였다. 본 실험에 사용된 호르몬 중 잉어뇌하수체를 어체중 1 kg당 4.4mg의 농토로 1$\~$3회 주사한 군은 $78.6\%$의 산란유도율을 보였고, human chorionic gonadotropin을 어체중 1kg당 1,100 IU의 농도로 1$\~$3회 주사한 군은 $66.6\%$의 산란유도율을 나타내었다.

• 한국양식학회지
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• 제11권4호
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• pp.513-519
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• 1998

인간의 태반성 성선자극 호르몬(HCG) 또는 성선자극 호르몬-방출 호르몬 유도체(GnRH-a) 단독 주사와 HCG+GnRH-a, GnRH-a+prostaglandin E sub(2) (PGF sub(2)), GnRH-a+pimozide를 복합적으로 주사하여 성숙한 암컷 쏘가리에서 배란 유도 실험을 하였다. 호르몬과 유도체의 반응 효과는 배란후 인공 수정하여 수정율과 배체형성율을 측정하여 결정하였다. 일반적으로 GnRH-a 실험군이 HCG 실험군에 비해서 수정율과 배체형성율 및 부화율이 높았다. HCG(5,000 IU/kg)+(GnRH-a(10 ${\mu}$g), GnRH-a(10 ${\mu}$g/kg)+PG$F^2$(500 ng/kg) 및 GnRH-a(10 ${\mu}$g/kg)+pimozide(1-5 mg/kg)에서 89% 이상의 높은 부화율을 보였다. 본 연구에서 사용된 성성숙 호르몬과 자극물질로 처리된 모든 암컷에서 배란이 유도되었지만, HCG+GnRH-a+dopamine과 GnRH-a+PG$F_2$+indometacin 처리군에서는 배란이 억제되었다. 이들의 결과는 산란시기에 여러 가지 성성숙 호르몬과 관련된 호르몬과 성성숙 억제물질(GRIF)이 분비된다는 점을 시사한다.