• The Korean Journal of Zoology
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• v.39 no.3
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• pp.266-272
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• 1996

Experiments were carried out to ascertain whether gonadotropin or a phorbol ester (12-O-tetradecanoyl phorbol-13-acetate, TPA) induces oocyte ovulation and stimulates prostaglandin synthesis by Rana ovarian follicles in vitro. Rana nigromaculata collected from underground in spring were utilized for the present experiment. Treatment of frog pituitary homogenate (FPH) or TPA to ovarian fragments in culture induced oocyte ovulation in a dose dependent manner and stimulated prostaglandin F2a (PGF$_2$$\alpha$ synthesis. Both treatruents were more effective in inducing the ovulation and PGF$_2$$\alpha$ secretion by the follicles obtained in May than those in April. A Protein kinase C inactivator, 1-(5-isoquinolinyl-sulfonyl)-2-methyl-piperazine (H-7), or cyclooxygenase inhibitor, indomethacin (IM) suppressed the FPH- or TPA-induced PGF$_2$$\alpha$ production, but IM failed to suppress the FPH- or TPA-induced ovulation. Time course of oocyte ovulation and PGF$_2$$\alpha$ secretion by FPH and TPA treatments were very similar to each other. FPH stimulated progesterone secretion by the follicle but TPA failed to do so. Taken together, the data presented here suggest that protein kinase C (PKC) in follicle play a role in the ovulation process of Rana nigromaculata, probably via prostaglandin synthesis.

• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.165-174
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• 2012

For horse breeders or managers, it is critical to understand the estrous cycle of mares. Breeding of mares cannot be successfully achieved throughout the whole year as mares breed seasonally. Mares are only able to breed when day length is more than 16 h, and this period is known as the breeding season. Their estrous cycle is approximately 21 days with 5-7 days of estrus and 14 to 15 days of a diestrus period. The estrous cycle of the mare is mainly controlled by gonadotropins, which control follicular development and ovulation. Mares exhibit unique ovulatory events which are not observed in other species. A LH surge occurs for several days, with levels of LH reaching their peak after ovulation. The LH level at the time of LH peak is lower than most other species. The unique anatomical structure of the ovaries of mares is known to limit the number of eggs ovulated. Several attempts have been made to develop chemical/hormonal agents which might be used to manipulate the timed ovulation of mares. Agents that have been tested include hCG, native GnRH, Deslorelin (Ovuplant, GnRH-agonist), Buserelin (GnRH analogue), equine pituitary extracts and equine chorionic gonadotropin (eCG or PMSG). However, the function, purity or stability of these agents is not reliable. Recombinant equine LH, an alternative agent for the timed ovulation, has been developed and tested for its biological activities, through the use of both in vitro and in vivo experiments. The reLH was suggested to be a reliable agent in inducing ovulation within 48 h after being administered through injection, when the size of dominant follicle is 35 mm in diameter.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.774-780
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• 2009

The objectives of this study were to test the efficacy of induction of estrus and determine the timing of ovulation in relation to preovulatory LH and estrogen surges in cycling Murrah buffaloes subjected to Heatsynch protocol (GnRH-$PGF_2{\alpha}$-Estradiol benzoate). In experiment 1, the buffaloes (n = 10) were treated with Heatsynch protocol and observed for estrus and ovulation. In experiment 2 and 3, 30 cycling Murrah buffaloes were used to investigate the efficacy of Heatsynch protocol in terms of conception rates in summer (experiment 2) and winter (experiment 3) seasons. Fixed time A.I. was performed in all the buffaloes at 48 and 60 h post-estradiol benzoate (EB) injection. All buffaloes responded to the Heatsynch protocol with expression of estrus for which ovulations were induced in 8 buffaloes (80%). Mean time interval from the EB injection to ovulation was 50.0${\pm}$2.0 h (range 44.0 to 60.0 h). The interval from the end of LH surge to ovulation was 18.5${\pm}$2.47 h (range 8 to 26 h). The interval from end of estrogen surge to ovulation was 26.75 ${\pm}$2.07 h (range 22 to 36 h). Mean LH peak after EB injection occurred at 20.81${\pm}$1.61 h (range 14 to 28 h) and mean estrogen peak after EB injection occurred at 9.62${\pm}$1.03 h (range 7 to 16 h). Hence, the mean estrogen peak preceded the mean LH peak by 11 h. It was observed that the percentage of conceptions to total number of estruses for control buffaloes was 18 and 30 in summer and winter, respectively, whereas it increased to 26 and 40 in Heatsynch treated buffaloes in respective seasons. The results suggest the possibility of using Heatsynch treatment followed by fixed time A.I. in buffaloes for fertility improvement, especially since the incidence of silent heat in buffaloes is very high.

• Journal of Embryo Transfer
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• v.29 no.2
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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.

• Research in Community and Public Health Nursing
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• v.7 no.2
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• pp.410-419
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• 1996

This study was reviewed from 1000 articles related to family planning from 1970 to 1990 and 20 articles associated with natural family planning from 1980 until the present. The purpose of natural family planning(NFP) is to identify the time ovulation of women themselves, to have intercourse with periodic abstinence, and to deliver a healthy child. The ultimate goal of NFP is to promote the family's health. The NFP method is described as periodic abstinence of intercourse to avoid pregnancy by identifying the ovulation time in the menstration cycle. Clinical symptoms and signs of reflection underlying changes in Estrogen and Progesterone are the change of basal body temperature, the change of cervical mucus and cervix, abdominal pain and breast tenderness. The types of NFP are the calender rthythm method, basal body temperature methods, cervical mucus method, symptothermal method, cyclo-thermal method and home based ovulation test kits. Recently the cyclo-thermal method involved. It is calendar rhythm method applied to B.B.T. For the cervical mucus method, when the estrogen level in the blood concentration is increased, the mucus begins to excrete, the amount of moist mucus increases while the mucus is clear, slippery, and smooth. For 3 days, this timing can be considered contraception. Fertility is at a maximum on the day mucus appears, abstinence for 3 days is a type of contraception. Sexual intercourse on a maximum day of mucus maximizes pregnancy potential. But, the contraception depends on the practice of a perfect rule. For basal body temperature methods, at ovulation time, the temperature increases $0.2^{\circ}C-0.5^{\circ}C$. Through the review of literature a high temperature above $0.2^{\circ}C$ for 3 days indicates that the previous 6 day period was ovulation and fertilization. The Symptothermal method is used to determine the prediction of ovulation through the observation of mucus excretion, high temperature, the change of cervical mucus, low abdominal pain, vaginal discharge, and breast change. Home based ovulation test kits are cervico-vaginal fluid aspiration, test a digital electric thermometer, body fluid(blood, saliva, urine) test kits, They are on the market. However, research on the contraception method is still in progress. For pregnancy it is still too early to use home based ovulation test kits because of deficit of reliability and simplicity more research on the technology is needed. It is suggested that NFP methods be included in nursing curriculum in order to educate NFP users how to effectively use NFP methods. Furthermore, this study has implications for the dissemination of NFP methods in terms of Korean policies of family planning and the support of community welfare agences.

• Journal of Aquaculture
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• v.12 no.3
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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.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.123-128
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• 2006

Production of cloned pigs by somatic cell nuclear transfer (SCNT) has unlimited value for developing critical biotechnology such as xenotransplantation. Various efforts have been made to establish this technology, and several litters of live piglets have been produced after transfer of SCNT embryos. However, the efficiency is very low compared to piglet production by artificial insemination or natural mating. So far, most studies have been limited to in vitro production of SCNT embryos. This study was conducted to standardize a surrogate recipient (gilts) for transfer of SCNT embryos to improve pregnancy rate. Potential surrogate gilts over 7 months of age were checked for their estrous status by observing external signs; vaginal fluid, vulva redness, vulva swelling, and standing response to back pressure. Viscosity of vaginal fluid was evaluated and classified as none (0), medium (1), and strong (2). Vulva redness and swelling was respectively assessed by none or shrink (0), medium (1), strong (2). Back pressure was estimated by an immediate move (0), standing less than 10 sec (1), and standing over 10 see (2). And then ovulation status of each surrogate was classified as pre-ovulation (PO-17 surrogates), just prior to ovulation (JPO-20 surrogates), in ovulation (IO-12 surrogates), just after ovulation (JAO-14 surrogates) and after ovulation (AO-24 surrogates) at the time of surgery for embryo transfer (ET). Real-time ultrasonographic scanners have been used for pregnancy diagnosis by observing amniotic vesicles. The first pregnancy diagnosis was done on Day 30 after ET and then repeated 2-week interval. In the results, SCNT embryos transferred into JPO surrogates gave better pregnancy rates (45%) than others (4% to 11%) on Day 30 after ET. These result indicates that surrogate gilts in a status just prior to ovulation can offer optimal condition to establish pregnancy by transfer of SCNT pig embryos.

• Journal of Embryo Transfer
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• v.30 no.4
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• pp.283-287
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• 2015

The aim of the present study was to investigate the ovulation rate and its relationship to fertilization ability in Landrace, Durock and Crossbred pigs. Gilts were natural mated at a body weight of at least 120 kg under the same hormone treatment. Embryos were surgically collected 1 day after natural mating (Day 0). Embryos derived from in vivo-fertilized oocytes were cultured in medium PZM-3. The ovaries were examined and the pathological findings were recorded. The number of corpus hemorrhagicum was counted, and was assumed to equal the ovulation rate. There was no difference in the number of corpus hemorrhagicum (20.4, 28.8 and 23.2) and ovulation (13.5, 26.8 and 17.2) in the Landrace, Durock and Crossbred pigs. The two pronucleus formation was 76.0, 80.0 and 86.9%. The Day-7 embryos had blastocyst rates of 68.0, 75.0 and 73.9%. There was no difference in the number of total cells and apoptotic cells. In the future, more studies require determining relationships between ovulation and fertilization rate in different species of pigs.

• The Journal of Dong Guk Oriental Medicine
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• v.1
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• pp.15-54
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• 1992

The present study was accomplished to investigate the relation between menstrual cycle and ovulation by studying the fluctuation of FSH, LH, estrogen and progesterone concentration in serum samples of selected senior high school women with normal and delayed menstrual cycles after administration of Jokyungijongoktang which was a widely used herb medicine for controlling abnormal menstrual cycles. The obtained results were summarized as follows : 1. There was a significant increase of FSH concentration in women with delayed menstrual cycles after administration of Jokyungjongoktang during the preovulatory phase. 2. Jokyungiongoktang produced a significant elevation od LH concentration in women with normal and delayed menstrual cycles, respectively, during the critical interval of ovulation. 3. Estrogen concentration was significantly decreased in women with delayed menstrual cycles after administration of Jokyungjongoktang during the critical interval of ovulation. 4. Peogesterone concentration significantly increase in women with delayed menstrual cycles after administration of Jokyungjongoktang, respectively, during the postovulatory phase. According to the above results, it can be considered that Jokyungjongoktang restore menstruation and pregnancy-related hormones to normal serum levels of women with normal menstrual cycles by activating maturation of ovum and action of estrogen during the preovulatory phase, ovulation and progesterone synthesis during the critical interval of ovulation, and nidation and endometrium sufficient for the continued pregnacy during the postovulatory phase in women with delayed menstrual cycles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.753-760
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• 1995

This study was conducted to determine the serum vitellogenin (VTG) concentration changes during the ovulation period in elkhorn sculpin, Alcichthys alcicornis. The results of sepacryl S-300 showed that the molecular weight of VTG could be 380,000. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis may indicate that the purified VTG consists of three subunits with molecular weights of 180,000, 118,000 and 85,000, respectively. Yolk protein purified from the egg extracts was eluted on an equilibrated sephacryl S-300 column, and its molecular weight was estimated 250,000. The precipitation lines of the female serum against the antiserum of the egg extracts were fused completely by immunoelectrophoresis and immunodiffusion analysis. VTG was detected in the serum, and hepatocytes from males injected with $17\beta-estradiol\;(E_2).$ Furthermore, VTG was immunochemically similar to yolk proteins. The concentration of VTG was high before ovulation $(9.80\pm0.81-11.02\pm0.09 mg/ml),$ and then decreased rapidly after ovulation $(less\;than\;6.19\pm0.59 mg/ml).$ This study suggested that VTG was synthesized in the liver by the action of $E_2$ and released to blood, and then incorporated into oocytes.