• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.459-467
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• 2002

The sex steroid hormone progesterone is essential for normal development and maturation of the endometrium in preparation for the embryo implantation and the maintenance of pregnancy. Insulin-like growth factor (IGF) system that is composed of IGF-I, IGF-II, IGF binding proteins (IGFBPs) is also involved in the maintenance of pregnancy. In addition, liver, kidney, and uterus is a target tissue for IGF system. However, the effect of exogenous progesterone on IGF system was not elucidated in female rats. Therefore, we investigated the effect of progesterone on insulin-like growth factors (IGFs) and IGF-binding proteins in serum, liver, kidney, and uterus in female ovariectomized rats. IGFs concentration was measured by radioimmuoassay (RIA) and IGFBPs levels by western ligand blotting(WLB). IGF-I concentration was increased in serum, liver, and uterus, but not in kidney of progesterone-treated ovariectomized rats, compared to control (P<0.05). IGF-II concentration was decreased in liver, but not in serum, kidney, and uterus of progesterone-treated rats, compared to control (P<0.05). IGFBP-3 was increased in serum, but not in liver of progesterone-treated rats, compared to control. IGFBP-2 was decreased in kidney, but not in others tissues of progesterone-treated rats, compared to control. These results suggest that progesterone may exert diverse physiological functions via the tissue-specific regulation of IGFs/IGFBPs system in female rats.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.315-318
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• 2013

This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-$17{\beta}$ (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L ${\times}$ Y) (respectively n=3) with excellent ability, and to provide a baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or more were used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushing feed before estrus. Each pig's blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analyses of P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-$17{\beta}$ were measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels were significantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen between the L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, the tendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a little higher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similar to the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swine production, these results proved the fact of the methods. And these results suggested that more studies about hormonal changes in sows according to seasonal and nutritional factors should be needed.

• Reproductive and Developmental Biology
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• v.35 no.4
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• pp.519-525
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• 2011

Growth hormone (GH) is obligatory for growth and development. But, there is controversy on the GH effect about reproductive processes of sexual differentiation, pubertal maturation, gonadal steroidogenesis, gametogenesis and ovulation. This study was conducted to investigate the effect of GH on estrus, ovulation and embryo implantation. The results obtained were as follows. GH stimulated to increase estrus rate (p<0.05), pregnancy rate (p<0.05), and total fetus number in mice treated for superovulation. Also, the correlation between GH and steroids, E2 and P4, at peri-estrus stage/ peri-ovulation stage/ peri-implantation stage of the superovulation-induced mice was examined. Consequently, GH co-injected with PMSG especially increased P4 level (p<0.05) at peri-estrus stage of superovulationinduced mice. In conclusion, GH co-treatment in superovulation system boosted the rate of estrus, pregnancy and total fetus by increasing progesterone level at peri-estrus stage of superovulation-induced mice.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.32-42
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• 2023

Fish reproduction is regulated by various neurohormones secreted from the brain and gonadotropic hormones secreted from the pituitary. Reproduction of eel (Anguilla japonica) is also regulated by these hormones. However, how the neurohormones regulate the secretion of pituitary hormones during sexual maturation is not completely understood. Previous studies have shown that neurohormones such as progesterone (P4), melatonin and serotonin (5-HT) are involved in the regulation of reproductive processes in some fish. In this study, the eel pituitary was primary cultured, and stabilized pituitary cells were treated with P4, 17β-estradiol (E2), melatonin, or 5-HT. The effect of these treatments on the expression of FSHβ, LHβ, GH and SL mRNA was, then, investigated. P4 increased the expression of FSHβ and LHβ in pituitary cells, and melatonin increased the expression of GH and SL as well as FSHβ and LHβ. However, 5-HT did not significantly affect the expression of these mRNA. These results suggest that P4 and melatonin may play some important roles in the early sexual maturation of eels.

• Journal of Veterinary Clinics
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• v.25 no.2
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• pp.79-84
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• 2008

For estimating the ovulation time in Miniature Schnauzer dogs during the estrous cycle, radioimmunoassay of plasma estradiol-$17{\beta}$ and progesterone concentrations was conducted on blood samples in 21 pregnant and 13 non pregnant dogs. When Day 0 was that plasma progesterone concentrations exceeded 4.0 ng/ml, on Day 64, parturition day, progesterone declined below 1.0 ng/ml with $0.92\;{\pm}\;0.29\;ng/ml$ and when Day 0 was that plasma progesterone concentrations declined below 1.0 ng/ml, on Day -64, progesterone increased above 4.0 ng/ml with $4.56\;{\pm}\;0.87\;ng/ml$. Gestational length was $63.71\;{\pm}\;1.35$ (Mean${\pm}$S.D.) days from plasma progesterone concentrations exceeded 4.0 ng/ml and was $66.29\;{\pm}\;1.98$ days from first male acceptance. The plasma estradiol-$17{\beta}$ concentrations reached maximum value with $28.20\;{\pm}\;2.86\;pg/ml$ on Day .2, and plasma progesterone concentrations reached $5.90\;{\pm}\;0.36 ng/ml, 5.18\;{\pm}\;0.32 ng/ml on Day 0, and the maximum of 61.58\;{\pm}\;10.47 ng/ml on Day 19 and 56.05\;{\pm}\;8.86\;ng/ml$ on Day 16 in pregnant and non pregnant dogs, respectively. Afterward, plasma progesterone concentrations declined below 1.0 ng/ml on Day 64 with $0.92\;{\pm}\;0.29\;ng/ml$ in pregnant cycles and on Day 58 with $0.95\;{\pm}\;0.63\;ng/ml$ in non pregnant dogs. No difference were found pregnant and non pregnant dogs in plasma estradiol-$17{\beta}$ and progesterone concentrations (p<0.01). Based on first male acceptance (Day 0), the maximum of plasma estradiol-$17{\beta}$ concentrations ($29.31\;{\pm}\;3.61\;pg/ml$) occurred on Day -1 and plasma progesterone concentrations exceeded 4.0 ng/ml on Day 2 in pregnant ($5.37\;{\pm}\;0.76\;ng/ml$) and non pregnant ($4.25\;{\pm}\;0.80\;ng/ml$) dogs. These results suggest that in Miniature Schnauzers, the ovulation occurred when plasma progesterone concentrations exceeded 4.0 ng/ml, 3 days after plasma estradiol-$17{\beta}$ peak and 2 days after first male acceptance.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.127-131
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• 1994

In order to examine the effects of PGF2$\alpha$ on intervals from weaning to estrus and serum progesterone levels seventeen crossbred primiparious sows were randomly alloted to two groups. One group was injected intramuscularly on the day of weaning with 10 mg PGF2$\alpha$ (10mg/2ml, Lutylase). The other group was treated with saline as a control. Serum progesterone concentrations were determined at 24 hour intervals for 12 days after weaning. A serum progesterone level in PGF2$\alpha$-treated group was reached to the lowest level(1.19$\pm$0.38 ng/ml) on day 3 after weaning and remained low(1.26~1.43ng/ml) thereafter. Whereas, the control group showed the lowest level of progesterone on day 4 after wearing, then showed a rapid increase up to 5.02$\pm$0.38ng/ml on day 8 and a rapid decrease was followed. The PGF2$\alpha$ treated group showed an interval from weaning to estrus(5.2$\pm$0.8 days) approximately 2 days shorter than the control(7.4$\pm$3.0 days)(p<0.05).

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.159-167
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• 1995

The relationship between palpable ovarian structure and milk progesterone levels were determined in 144 dairy cows. Depending on the ovarian structure and diseases were divided into two groups, Group I (absence of functional luteal tissue in ovary and <2ng/ml in milk progesterone levels) and Group II(presence of functional luteal tissue in ovary and ${\geq}2ng/ml$ in milk progesterone levels) 1. Among 69 cows of group I, dysfunction of ovary, atropy of ovary, follicle is ovary, follicular cyst and corpus luteum albicans were 17(11.8%), 19(13.2%), 14(9.7%), 3(2.1%) and 16 cows(11.1%), and among 75 cows of group II, corpus luteum A, B and C were 16(11.1%), 17(11.8%) and 42 cows(29.2%), respectively. 2. In Group I, milk progesterone concentrations were <1ng/ml in 55 cows(79.9%). Conversely in Ggroup II, milk progesterone concentrations were ${\geq}4ng/ml$ in 55 cows(73.3%). 3. The mean(${\pm}SE$) concentrations of milk progestsrone in the Group I and II were $1.62{\pm}0.45$ and $7.64{\pm}0.68ng/ml$, respectively, and CR test showed the difference in milk progesterone concentrations between the two groups to be statistically significant(p<0.01). 4. The mean(${\pm}SE$) concentration of milk progesterone in cows with corpus luteum A, B and C were $8.11{\pm}1.83$, $8.48{\pm}1.30$ and $7.12{\pm}0.82ng/ml$, respectively, there was no significant relationship between palpable corpora luteum structure and milk progesterone concentration. 5. The accuracy of ovarian diagnosis was 82.6 and 20.2% in the Group I and II, respectively, and Chi-square test showed the difference in accuracy between the two groups to be statistically significant (p<0.001). 6. The agreement between the rectal palpation and milk progesterone concentrations in ovarian disease was 50%.

• Journal of Embryo Transfer
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• v.23 no.3
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• pp.177-181
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• 2008

This study was performed to investigate the effects of hCG treatment on pregnancy and delivery rates in the Hanwoo recipients. There were significantly higher pregnancy and delivery rates in the recipients treated with hCG at 7 days after artificial insemination (p<0.05), respectively. The SCNT embryos from bovine fetal fibroblast cells were transferred into the synchronized recipients. The recipients were administered saline (n=89) or hCG (1,500 IU) (n=48) at 7 days after heat, respectively. The pregnancy rate was significantly higher in the recipients treated with hCG compared to that of saline treated group (p<0.01), however, the delivery rate was not different in both treated groups. The concentration of plasma progesterone (P4) was not different in both groups before hCG treatment, but the P4 level was increased significantly in hCG treated group after hCG injection (p<0.05). Although the pregnancy rate was very high in early stage of pregnancy, it was decreased dramatically after 50 days of pregnancy and maintained basal level. Taken together, the treatment of hCG in the SCNT recipients after day 7 of heat was effective method to increase the P4 concentration and to increase the pregnancy rate. But it did not affect directly to delivery.

• The Korean Journal of Zoology
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• v.32 no.4
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• pp.329-338
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• 1989

Present study examined the effect of intermittent versus continuous infusion of progesterone(P) on LHRH release in uiuo from the mediobasal hvpothalamus of ovariectomiEed, estradiol-primed adult rats bearing push-pull cannulae. Three experimental groups were studied: 1) control (perfusion medium only),2) intermittent perfusion of P (10-min on,20-min off, and 3) continuous perfusion of p. p (10 ng/mll was directly infused into the MBH following a 3 hr basal collection. Perfusates were collected at 10 min intents린s on ice and LHRH release was measured by LHRH radioimmunoassav. Cycle detector analysis revealed that the spontaneous HRH output in the control group was pulsatile over a 7 hr push-pull perfusion period. The mean basal LHRH release, pulse amplitude and pl서se period were 0.68 $\pm$ 0.03 ps110 min, 1.15 $\pm$0.08 pg and 60 $\pm$ 9 min, respectivelv. Intermi구eat perfusion of P clearly stimulated the mean LHRH release (pre-P vs post-P: 1.14 $\pm$ 0.18 vs 1.99 $\pm$ 0.53 pg) without changes in LHRH pulse frequency. In contrast to intermittent infusion of p, continuous administration of P faithed to modify LHRH release, since the mean LHRH release and pulse amplitude between pre-P and post-P perfusion urere similar. The in vitro study clearly showed that intermittent, but not continuous administration of P is effective in stimulating LHRH release. Therefore, it appears that rhythmic secretion of P mal be the erective signal for activating the neural LHRH apparatus.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.397-414
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• 2008

In order to evaluate conception rate of Hanwoo in northwestern region of Gyeongsang-nam-do, we investigated conception rate and reduction of reproductive disorder rate after artificial insemination (AI) in 1,000 heads of breeding cows, This study showed that 80.9% of cows were classified as fertility after 1st and 2nd AI. For a accurate pregnancy diagnosis with practicing ovariectomy and histeotomy, we comparatively investigated each of 80 slaughtered cows, including 30 of non-pregnancy, and used enzyme-linked immunosorbent assay (ELISA) for estimation of plasma progesterone concentration and serum luteal hormone. The mean diameter of non-pregnant corpus luteum is $18.9{\pm}4.2{\times}15.6{\pm}3.6 mm$ and that of pregnant corpus luteum is $22.5{\pm}2.7{\times}18.7{\pm}2.9 mm$. This indicates that corpus luteum is more developed in the ovary of pregnant than non-pregnant cows (P<0.05). The diameter of pregnant corpus luteum according to the stage of pregnancy showed $21.3{\pm}2.4{\pm}18.4{\pm}2.6 mm$ in early stage (1-3 month), $23.4{\pm}2.8{\times}19.1{\pm}2.7 mm$ in middle stage (4-6 month) and $22.8{\pm}3.0{\times}18.8{\pm}2.4mm$, in last stage (7-9 month). This indicates that corpus luteum in middle and last stage is more significantly developed than that of early stage(P<0.05). The mean plasma progesterone concentration of cows showing size of non-pregnant corpus luteum was $4.58{\pm}0.92ng/ml$ and that of pregnant corpus luteum $8.26{\pm}0.98ng/ml$. Thus, it was more significantly increased in pregnant corpus luteum(P<0.02).. However, it was low to $0.58{\pm}0.39ng/ml$. in estrus (corpus albicans). The plasma progesterone concentration according to gestation period was high in proportion to the degree of development in corpus luteum and more significantly increased (P<0.05) and maintained in middle and last state than early state. The concentration was sharply decreased to $0.56{\pm}0.32ng/ml$ at parturition. As a consequence, we can practice the early pregnancy diagnosis by confirming non-pregnancy when the mean plasma progesterone concentration is below 1ng/ml 19 to 22 days after AI and this can be available to diagnose reproductive disorder.