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        검색결과 39

        21.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 돼지 체외수정란의 배양시스템의 최적화를 위하여 수행되었다. 기본배양액으로는 NC-SU-23을 사용하였으며, 실험 1에서는 IGF-I이 각각 0, 1, 10, 100 ng/의 농도로 첨가된 배양액에서 배양하여 분할율, 배반포 발달율과총 세포수를 확인하였다. 농도 경사에 따른 분할율은 차이가 없었으나(65.5%~69.5%), 배반포 발달율에 있어서는 10 ng/의 농도로 첨가하였을 경우가 가장 높았다(P<0.05). 실험 2는 배 아 유전자 활성
        4,000원
        22.
        2002.11 구독 인증기관 무료, 개인회원 유료
        Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to stimulate proliferation and differentiation of various somatic cells, including placental trophoblasts and also to enhance fetal growth and development when maternally administered. Since an increase of the expression of placental EGF and IGF-I receptors in rat, mouse, and human with the gestation advanced, both EGF and IGF-I were considered to play pivotal roles on fetal growth by regulating some function of placental cells. Amino acids are crucial importance for both maternal and fetal requirements of energy source and essential constituent of fetal mass during pregnancy. Impaired fetal and placental uptake of amino acids has been observed in several models of growth retardation in the rat. Amino acid is concentrated in the fetal side through active transport by amino acid transporters and is one of the important metabolic fuels for the fatal growth. Therefore, at first plasma amino acid concentrations in mothers and fetuses were measured as an index of uphill transport across the placenta associated with EGF and IGF-1. The EGF administration at the concentration of 0, 0.1, or 0.2 /g to pregnant rats from day 18 to 21 of gestation apparently increased fetal/maternal ratio of serum proline concentration and also fatal growth in EGF dose-dependent manner. When IGF-I in doses of 0, 1, 2, and 4 /g were administrated, the ratio of leucine, isoleucine, tryptophan, phenylalanine, tyrosine and also fetal growth significantly increased with a dose-dependent manner. These results suggested that EGF and IGF-I enhanced fatal growth by, as one of its possible mechanisms, promoting placental activity to transfer some amino acid supplies from the mother to the fetus in late pregnancy.
        3,000원
        30.
        1998.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 성장인자 EGF, IGF-1, EGF+IGF-1 이 소 난포란의 체외성숙에 미치는 영향을 규명하기 위하여 실시하였다. 소 난포란의 체외성숙 시 EGF를 농도별 (10, 50 및 100ng/m1)로 첨가하여 실험한 결과 통계학적 유의성은 인정되지 않았으나 24시간 배양 후 성숙율은 대조군에 비하여 높은 경향을 나타내었다. 소난포란의 체외성숙 시 EGF와 IGF-1을 병용 처리하여 실험한 결과, EGF 또는 IGF-1 단독처리 군에 비하여 병용처
        4,000원
        31.
        1997.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!
        5,200원
        35.
        2016.10 서비스 종료(열람 제한)
        Background : Insulin-like growth factor 1 (IGF-1) appears to enhance the differentiation of osteoblasts and to activate the mineralization of bone. Hence, the aim of this study was to investigate the effects of ginseng complex on the remodeling of rats tibia. Methods and Results : Ginseng complex significantly increased serum IGF-1 by 58% and 34.5% than the control, respectively. Treatment with α-amylase when manufacturing these extracts remarkably increased the concentration of IGF-1 by 63% and 36% above the control, respectively. This ways that this ginseng complex, especially α-amylase treated extracts, contained a higher level of IGF-1 secretion in the ginseng complex groups. In addition, increases of 8% in femuf length were found after 12 weeks of oral administration with ginseng complex (300mg/kg). Conclusion : These results mean that ginseng complex have beneficial effects on bone effects on bone growth via IGF-1.
        36.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        The insulin-like growth factor (IGF) pathway is a key signal transduction pathway involved in cell proliferation, migration, and apoptosis. In dairy cows, IGF family proteins and binding receptors, including their intracellular binding partners, regulate mammary gland development. IGFs and IGF receptor interactions in mammary glands influence the early stages of mammogenesis, i.e., mammary ductal genesis until puberty. The IGF pathway includes three major components, IGFs (such as IGF-I, IGF-II, and insulin), their specific receptors, and their high-affinity binding partners (IGF binding proteins [IGFBPs]; i.e., IGFBP1–6), including specific proteases for each IGFBP. Additionally, IGFs and IGFBP interactions are critical for the bioactivities of various intracellular mechanisms, including cell proliferation, migration, and apoptosis. Notably, the interactions between IGFs and IGFBPs in the IGF pathway have been difficult to characterize during specific stages of bovine mammary gland development. In this review, we aim to describe the role of the interaction between IGFs and IGFBPs in overall mammary gland development in dairy cows.
        37.
        2011.03 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 경상북도 일원에서 수집한 자귀나부(Albizia julibrissin)를 포함한 두과식물 17종에서 인체의 혈당저하제의 원료로 사용되는 pinitol 함량을 식물체 부위별로 조사하였는 바, 결과를 요약하면 아래와 같다. 1. 수집한 17개 두과식물 종간에는 pinitol 함량에서 유의적인 차이가 인정되었으며, 종별 총 pinitol 함량에서는 비수리(Lespedeza cuneata)가 가장 높은 값을 보였다. 식물체 부위별로 pinitol 함량을 살펴보면 대체적으로 잎, 줄기, 꼬투리, 종자, 뿌리의 순으로 많았다. 2. 잎에서 비교적 많은 pinitol 함량을 보인 식물은 골담초, 족제비싸리, 돌동부 및 비수리로 각각 59.9 mg/g, 62.2 mg/g, 69.6 mg/g, 65.4 mg/g으로 약 60 mg/g이상을 나타내었고, 줄기의 경우는 황기가 34.0 mg/g으로 비교적 높게 나타났으며, 뿌리에서는 칡이 24.6 mg/g으로 가장 높았으며, 감초와 골담초가 16.9 mg/g, 16.5 mg/g으로 그 다음으로 높았다. 그러나 꼬투리나 종자에서는 제비콩(52.5 mg/g)과 비수리(24.9 mg/g)를 제외하고 pinitol 함량은 잎이나 줄기에 비해 모든 조사식물에서 상대적으로 낮았다. 3. 조사대상 식물체의 pinitol 함량과 수확 가능한 식물체량을 고려할 때, 실제 약용으로 이용 가능성이 가장 높은 식물은 비수리이었다. 비수리의 경우 전국적인 수집을 통해 pinitol 함량이 높은 계통을 선발한다면 이용가능성 이 높은 pinitol 추출용 계통의 선발이나 보다 이용가치가 높은 새로운 품종의 육성도 가능할 것으로 생각된다.
        38.
        2010.09 서비스 종료(열람 제한)
        Previously we have succeeded to isolate stem cells (HEAC) from human eyelid adipose tissue, and functionally differentiate them into insulin-secreting cells. In the present study, we examined whether insulin family members might affect the insulinogenic differentiation of HEAC. Insulin treatment during culture affected little on the insulin and c-peptide secretions from HEAC after culture. However, insulin-like growth factor (IGF) 1 treatment decreased both secretions, whereas IGF2 greatly increased the secretions in a glucose-dependent manner. HEAC treated with IGF2 showed stronger expression of Pdx1, Isl1, Pax6 and PC1/3 genes compared to the control. They also showed distinct staining with insulin and c-peptide antibodies, and dithizone. While insulin or IGF2 treatment increased total cell number by 1.3- or 1.5-fold, respectively, each treatment increased the amount of insulin secretion by 27.1- or 78.1-fold, respectively. IGF2-enhanced insulinogenic differentiation was completely blocked by an antibody against insulin receptor (IR), but not by an antibody against IGF1 receptor (IGF1R). Differentiated HEAC showed expression of both IR and IGF1R genes while they expressed neither IGF2 nor IGF2R genes. Based upon these results, it is suggested that whereas IGF1 might inhibit the insulinogenic differentiation of HEAC, insulin and IGF2 could enhance the differentiation, and that the enhancing effect could be mediated via IR.
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