• Title/Summary/Keyword: calcium ionophore

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Anti-inflammatory and Anti-Pruritonic Effects of WSY-1075 composited with Medicinal Plants on the Activated Rat Peritoneal Mast cells and Mouse Pruritus (활성화된 렛트 비만세포와 마우스 소양증에 대한 한약재로 조성된 WSY-1075의 항염증 및 항소양 효과)

  • Hwang, Sung Yeoun;Lee, Seung Ho;Lee, Chia Wei;Kim, Jang Ho;Jang, Seon Il;Kim, An Na;Kim, Hong Jun
    • The Korea Journal of Herbology
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    • v.28 no.4
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    • pp.93-100
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    • 2013
  • Objectives : This study was to evaluate the anti-inflammatory and anti-pruritic effects of WSY-1075 composited with Corni Fructus, Angelica gigantis Radix, Lycii Fructus, Ginseng Radix, Cervi parvum Cornu and Cinnamomi Cortex in rat peritoneal mast cells (RPMCs) and scratching mouse model. Methods : WSY-1075 was prepared by extracting with 30% ethanol. In the present study, we investigated the effect of WSY-1075 on the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$) and histamine in rat peritoneal mast cells (RPMCs) activated with phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187, and on the scratching behavior in mice treated with pruriogens. Results : WSY-1075 was not cytotoxic effect in used all concentration. PMA plus A23187 treatment significantly increased TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 production compared with media control in RPMCs. However, TNF-${\alpha}$, $IL1{\beta}$ and IL-6 production increased by PMA plus A23187 treatment were significantly inhibited by WSY-1075 (200 ${\mu}g/mL$ and 400 ${\mu}g/mL$). WSY-1075 also inhibited the histamine release from RPMCs stimulated by compound 48/80, which promotes histamine release. Moreover, WSY-1075 administration had an inhibitory effects on the scratching behavior induced by pruritogen (compound 48/80, histamine, serotonin and substence P) in ICR mice. Conclusion : These results suggest that WSY-1075 administration (200 mg/kg or 400 mg/kg) has the anti-inflammatory and anti-pruritic effects on the activated rat peritoneal mast cell and mouse pruritus. WSY-1075 has a potential use as a composition of medicinal plants for treatment against inflammation- and pruritus-related disease.

Effect of Electric fusion Methods on Cell Fusion Rate and Embryo Development by Somatic Cell Nuclear Transfer in Korean Native Cattle(KNC) (한우 체세포를 이용한 핵이식에서 전기융합 방법이 융합율 및 배발달율에 미치는 영향)

  • 김은국;김정욱
    • Journal of Embryo Transfer
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    • v.18 no.3
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    • pp.171-178
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    • 2003
  • This study was conducted to investigate the effect of electric fusion methods on cell fusion rate and embryo development by somatic cell nuclear transfer in Korean Native Cattle. The KNC ear cell was cultured in vitro for confluence in serum starvation condition(DMEM+0.05% FBS) for cell confluence. The zona pellucida of IVM oocytes were partially dissection using micro pipette. Ear cells were transferred into an enucleated oocyte. The reconstructed embryos were electrically fused with Zimmermann Cell Fusion Medium(ZCFM). Nuclear transfer embryos were activated with a combination of 10${\mu}{\textrm}{m}$ calcium ionophore(5 min) and 2.0mM 6-DMAP(3 hr). The activated embryos were cultured in CR1 -aa medium contains 0.3% BSA or 10% FBS at 37$^{\circ}C$, 90% $N_2$, and 5% $CO_2$in incubator for 6 days. The fusion rates were 51.6%(chamber) and 68.9%(needle), respectively and there were significantly difference between the fusion method(P<0.05). But, lysis rates were not significantly different(10.7%, 11.5%), respectively. The cleavage rates were significantly different between the chamber method(73.2%) and needle method(80.3%), respectively(P<0.05). The rates of early embryos(2∼4cells) and blastocysts of chamber and needle methods were 54.1%, 61.1% and 18.4%, 26.3% respectively, and needle method was significantly higher than chamber method(P<0.05). But, morulae formation rate were not significantly differences between the chamber(6.7%) and needle(6.2) method(P <0.05). These result suggest that electric fusion of needle method was to be profitable for nuclear transfer embryo fusion rate, blastocyst formation rate and reduce of oocyte lysis.

Na-Ca Exchange in Sarcolemmal Vesicles Isolated from Cat Ileal Longitudinal Muscle (고양이 회장 종주근에서 Na-Ca 교환 기전의 특성에 관한 연구)

  • Woo, Jae-Suk;Suh, Duk-Joon;Kim, Yong-Keun;Lee, Sang-Ho
    • The Korean Journal of Physiology
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    • v.23 no.2
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    • pp.237-252
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    • 1989
  • Effect of a $Na^+$ gradient on $Ca^{2+}$ uptake was studied in isolated sarcolemmal vesicles of cat ileal longitudinal muscle. $Ca^{2+}$ uptake was markedly stimulated in the presence of an outwardly directed $Na^+$ gradient. External $Na^+$, monensin and A23187 abolished the $Na^+-dependent$ $Ca^{2+}$ uptake. Monovalent cations such as $K^+$, $Li^+$, $Rb^+$, $Cs^+$ and choline could not substitute for $Na^+$ in enhancement of $Ca^{2+}$ uptake. Divalent cations such as $Ba^{2+}$, $Sr^{2+}$, $Mn^{2+}$ and $Cd^{2+}$ but not $Mg^{2+}$ inhibited the $Na^+-dependent$ $Ca^{2+}$ uptake. Increase in external pH in the range of 6.0 to 8.0 stimulated the $Na^+-dependent$ $Ca^{2+}$ uptake. Amiloride inhibited the $Na^+-dependent$ $Ca^{2+}$ uptake at concentrations above 0.5 mM, whereas diltiazem or vanadate did not. The apparent Km of the $Na^+-dependent$ $Ca^{2+}$ uptake for $Ca^{2+}$ was 18.2 ${\mu}M$ and apparent Vmax was 689.7 pmole/mg protein/5 sec. Kinetic analysis of the $Na^+-dependent$ $Ca^{2+}$ uptake showed a noncompetitive interaction between internal $Na^+$ and external $Ca^{2+}$. The dependence of $Ca^{2+}$ uptake on internal $Na^+$ showed sigmoidal kinetics and Hill coefficient for internal $Na^+$ was 2.52. Inside positive membrane potential generated by imposing an inwardly directed $K^+$ gradient and valinomycin significantly stimulated the $Na^+-dependent$ $Ca^{2+}$ uptake. These results indicate that a $Na^+-Ca^{2+}$ exchange system exists in the sarcolemmal membranes isolated from cat ileal longitudinal muscle and it might operate as an electrogenic process.

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Anti-Atopic Effects of Mixed Extracts from Date Plum, Persimmon, and Mulberry Leaves (고욤잎, 감잎 및 뽕잎 복합추출물의 항아토피 효과)

  • Cho, Byoung Ok;Yin, Hong Hua;Shin, Jae Young;Fang, Chong Zhou;Chang, Che Denis;Jang, Seon Il
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.4
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    • pp.501-509
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    • 2016
  • The present study investigated the anti-atopic effects of mixed extracts from date plum, persimmon, and mulberry leaves (DPME) on atopic dermatitis (AD)-like skin lesions in hairless mice. The in vivo results demonstrated that DPME treatment significantly reduced the dermatitis clinical score and epidermal thickness in AD-like skin lesions. Histological analyses showed that DPME treatment strongly inhibited dermal infiltration of inflammatory cells and activity of mast cells in AD-like skin lesions. DPME treatment inhibited production of serum IgE and interluekin (IL)-4 in hairless mice with AD. Moreover, DPME treatment significantly suppressed production of tumor necrosis factor $(TNF)-{\alpha}$ and IL-6 cytokines in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 human mast cells. In addition, DPME treatment reduced production of pro-inflammatory mediators (nitric oxide, prostaglandin E2, $TNF-{\alpha}$, and IL-6) in lipopolysaccharide-stimulated RAW 264.7 macrophages. Therefore, the results of this study indicate that the anti-atopic and anti-inflammatory effects of DPME may be involved in the regulation of inflammatory responses, suggesting that DPME may be used as an anti-atopic dermatitis material and natural anti-inflammatory ingredient.

Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionicgonadotropin Receptor

  • Min, K. S.
    • Proceedings of the KSAR Conference
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    • 2000.10a
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    • pp.10-12
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    • 2000
  • Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

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Effects of Crormakalim on the Release of Mediators in Hypersensitivity of Guinea pig (Cromakalim이 해명의 과민반응 매개체 유리에 미치는 영향)

  • Ro, Jai-Youl;Kim, Kyung-Hwan
    • The Korean Journal of Pharmacology
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    • v.29 no.2
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    • pp.263-274
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    • 1993
  • Potassium $(K^+)$ channels are present in airway smooth muscle cells, and their activation results in hyperpolarization and relaxation. Because these effects may have therapeutic relevance to hypersensitivity and asthma, we examined the effect of a potassium channel activator, cromakalim (BRL 34915, CK) on the release of mediators from superfused tracheal and parenchymal strips after passive sensitization with $IgG_1$ antibody. Both tissues were superfused with CK $(2{\times}10^{-6}\;M)$ for 30 min and challenged with CK and antigen (Ox-HSA). Using monodispersed, partially purified, highly purified guinea pig lung mast cells, we also examined the effect of CK on mediator release from these cells after passive sensitization with $IgG_{1}$ antibody $({\alpha}-OA)$. Guinea pig lung mast cells were purified using enzyme digestion method, count current elutriation, and discontinuous Percoll density gradient. After CK pretreatment, passively sensitized mast cells were challenged with varying concentration of antigen (OA, immunological stimuli) or with varying concentration of calcium ionophore (CaI, non-immunological stimuli). Histamine (Hist) release was determined by spectrophotofluorometry, and leukotrienes (LT) by radioimmunoassy. CK pretreatment decreased Hist by 35% and LT release by 40% in the antigen-induced tracheal tissue after $IgG_1$ sensitization but did not decrease the contractile response. In the antigen-induced parenchymal tissue CK decreased Hist release by 25% but poorly decreased LT. Both immunologic and non-immunologic stimuli caused a dose-dependent release of Hist and LT from monodispersed, partially purified and highly purified lung mast cells. Verification of LT release was obtained by the use of 5-lipoxygenase inhibitor, A64077 (Zileuton). CK decreased Hist and LT release by 20% respectively in the OA-induced guinea pig lung mast cells after $IgG_1$ sensitization. The inhibitory effects of CK on the Hist and LT release in the Ox-HSA-induced airway smooth muscle tissues or in the OA-induced and CaI-induced mast cells after $IgG_1$ sensitization were completely blocked by TEA and GBC. These studies show that guinea pig lung mast cells seem to be an important contributor to LT release, and that CK (which has been known as an airway smooth muscle relaxant) can in part act to inhibit mediator release in the antigen-induced airway smooth muscle, and that CK may also act to inhibit mediator release in the OA-induced and CaI-induced highly purified mast cells. These results suggest that Hist and LT release evoked by mast cell activation might in part be associated with $K{^+}4 channel activity.

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Effect of Protein Supplementation, O2 Concentration and Co-Culture on the Development of Embryos Produced by Nuclear Transfer Using Cultured Cumulus Cells in Hanwoo (Korean Cattle)

  • Im, G.S.;Yang, B.S.;Park, S.J.;Im, S.K.;Yang, B.C.;Yi, Y.J.;Park, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.9
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    • pp.1260-1266
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    • 2001
  • The effect of protein supplementation, $O_2$ concentration and co-culture on the development of embryos produced by nuclear transfer using cultured cumulus cell was investigated. Recipient oocytes and cumulus cells were obtained from the ovaries of the slaughtered Hanwoo cows. Donor cumulus cells were cultured in Dulbecco's modified Eagle medium containing 10% fetal bovine serum at 5% $CO_2$ in air at $38.5^{\circ}C$. The 1 to 6 passages of cumulus cells were isolated and used as donor cells. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. One $15{\mu}s$ pulse of 180 volts was applied to induce the fusion between karyoplast and cytoplast. The fused embryos were activated with $10{\mu}M$ calcium ionophore for 5 min and 2 mM 6-dimethylaminopurine for 3 h. To examine the effect of protein supplementation, nuclear transfer (NT) embryos were cultured in one of the following 4 treatments : 1) CR1aa + 3 mg/ml BSA for 7 days ; 2) CR1aa + 10% FBS for 7 days ; 3) CR1aa + 1.5 mg/ml BSA + 5% FBS for 7 days ; and 4) CR1aa + 3 mg/ml BSA for first 3 days and then CR1aa + 1.5 mg/ml BSA + 5% FBS for 4 days. Culture took place at 5% $CO_2$, 5% $O_2$ and 90% $N_2$ at $38.5^{\circ}C$. Although there were no significant differences in cleavage rate among different protein supplements, the rates of blastocyst formation were significantly different. When NT embryos were cultured in the medium supplemented with only BSA, they could develop to only morula not to blastocyst. However, when FBS was supplemented, NT embryos developed to blastocyst stage. In order to investigate the effect of $O_2$ concentration and co-culture, NT embryos were cultured in CR1aa + 1.5 mg/ml BSA + 5% FBS with or without cumulus cell co-culture at an atmosphere of 5% $CO_2$ in air (20% $O_2$) or 5% $CO_2$, 5% $O_2$, 90% $N_2$ (5% $O_2$) at $38.5^{\circ}C$ for 7 days. The percentage of blastocyst development was significantly higher when the NT embryos were cultured at an atmosphere of 5% $O_2$ than that of 20% $O_2$ (p<0.05). However, there was no significant difference between with and without cumulus cell co-culture at an atmosphere of 5% $O_2$ or 20% $O_2$. Fifty embryos were transferred to 25 recipients and 5 recipients were pregnant at 100 days. From 5 pregnant cows, only one cow was delivered of female twin. In conclusion, the embryos reconstructed by enucleation of metaphase II oocytes and introduction of the cycling and quiescent cumulus donor cells in Hanwoo had developmental potential to term after embryo transfer to recipient cows.

Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionic Gonadotropin Receptor

  • Min, K.S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.4
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    • pp.357-364
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    • 2000
  • Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

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Anti-inflammatory Effect and Antioxidative Activities of Ingredients used in Bibimbab (비빔밥 재료의 항염증 및 항산화 효과)

  • Ko, Yu-Jin;Seol, Hui-Gyeong;Lee, Gyeong-Ran;Jeong, Gye-Im;Ryu, Chung-Ho
    • Journal of Life Science
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    • v.23 no.2
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    • pp.213-221
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    • 2013
  • Bibimbab (mixed rice) is a traditional Korean one-dish meal. This study was carried out to investigate the anti-inflammatory and antioxidative effects of raw and seasoned ingredients used in Bibimbab (Cucurbita moschata P., Platycodon grandiflorum A., Vigna radiata L., Porphyra yezonensis udea, Allium ampeloprasum L., Pterdium aguilinum, Raphanus sativus). Human mast cells (HMC-1) were pretreated with 70% ethanol extracts of Bibimbab and further cultured for an appropriate time after the addition of phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. Cell viability was determined by an MTT assay. None of the ingredients showed cytotoxic effects at a concentration of 1.0 ${\mu}g/ml$. Anti-inflammatory effects were analyzed at 0.01, 0.1, and 1.0 mg/ml concentrations of the raw, seasoned ingredients of PMA. A23187 stimulated HMC-1. Among the various ingredients, seasoned A. ampeloprasum L. extract showed the highest inhibition of TNF-${\alpha}$ and IL-6 secretion (90% and 93%, respectively) at a concentration of 1.0 mg/ml. The R. sativus extract showed the highest inhibition (85%) of IL-8 secretion. DPPH analysis of the antioxidation properties of the ingredients showed that raw and seasoned A. ampeloprasum extracts exhibited the highest DPPH free radical scavenging activity (67.50 and 73.65%, respectively). These results suggest that seasoned ingredients used in Bibimbab have lower anti-inflammatory effects in relation to TNF-${\alpha}$ and IL-6 secretion than raw ingredients in PMA- and A23187-treated HMC-1. In addition, the seasoned ingredients showed a tendency to increase antioxidative activity. Therefore, the ingredients used in Bibimbab have potential as anti-inflammatory and antioxidation agents.

Effect of Fusion Procedure on the Development of Embryos Produced by Somatic Cell Nuclear Transfer in Hanwoo (Korean Cattle) (한우에서 융합방법이 체세포 핵이식 수정란의 발달에 미치는 영향)

  • Im, G.S.;Yang, B.S.;Park, S.J.;Chang, W.K.;Park, C.S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.4
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    • pp.365-373
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    • 2000
  • The purpose of this study was to investigate the effects of the fusion pulses and fusion media on fusion rate and the development of embryos produced by somatic cell nuclear transfer in Hanwoo (Korean cattle). Nuclear donor cumulus and fetal fibroblast cells were cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at 38.5$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. The cumulus cell and cytoplast were fused using one pulse of 70 volts for 40$mutextrm{s}$, two pulses of 70 volts for 40$mutextrm{s}$ and one pulse of 180 volts for 15$mutextrm{s}$. The fetal fibroblast cell and cytoplast were fused using one pulse of 180 volts for 15$mutextrm{s}$ or 30$mutextrm{s}$. The cumulus cell and cytoplast were fused using mannitol and Zimmerman cell fusion medium (ZCFM) as a fusion medium. The fused embryos were activated after the fusion with 10 $\mu$M calcium ionophore for 5 min and 2 mM 6-dimethyl- aminopurine for 3 h. The nuclear transfer embryos were cultured in 500 ${mu}ell$ well of modified CR1aa supplemented with 3 mg/$m\ell$ BSA in th $\varepsilon$ four well dish cove red with mineral oil. After 3 days culture, culture medium was changed into modified CRlaa medium containing 1.5 mg/$m\ell$ BSA and 5% FBS for 4 days. The incubation environment was 5% $CO_2$, 5% $O_2$, 90% $N_2$ at 38.5$^{\circ}C$. When the cumulus cells were fused with enucleated oocytes by three different fusion pulses, one pulse of 180 volts for 15 $mutextrm{s}$ yielded the highest fusion rate and developmental rate to blastocyst among the pulses (P<0.05). When the fetal fibroblast cells were fused with enucleated oocytes, one pulse of 180 volts for 30$mutextrm{s}$ yielded significantly higher fusion rate compared with that for 15 $mutextrm{s}$(P<0.05). The present result indicates that the fusion rate between karyoplast and cytoplast was affected by the cell type and the optimal fusion condition was different according to cell type or size. When the fusion was conducted by the use of mannitol and ZCFM, the fusion rate was 71.2% and 65.8%, respectively. The developmental rates to blastocyst were 37.8% and 39.8%, respectively. There was no significant difference between two fusion media in the developmental rate of cumulus cell nuclear transfer embryos. These results indicate that optimal electric current should be selected according to cell type.

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