• Asian-Australasian Journal of Animal Sciences
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• 제10권2호
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• pp.233-239
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• 1997

A mammary epithelial cell line (MAC-T) established as a model for lactation was utilized to identify and characterize effects of various hormones upon insulin-like growth factor binding protein secretion. Ligand and immunoblot analyses of conditioned media indicated that insulin-like growth factor binding protein-2 was secreted by MAC-T cells. Insulin-like growth factor-I stimulated insulin-like growth factor binding protein-2 secretion in a dose-dependent manner, but prolactin and bovine somatotropin did not alter insulin-like growth factor binding protein-2 secretion. Insulin increased and cortisol decreased insulin-like growth factor binding protein-2 secretion. Effects of insulin-like growth factor-I on insulin-like growth factor binding protein-2 secretion support previous studies using primary cultures of bovine mammary cells and bovine fibroblasts. Effects of cortisol and insulin on insulin-like growth factor binding protein-2 secretion may be explained by changes in protein synthesis. In addition, supraphysiological doses of insulin can cross-react with the insulin-like growth factor-I receptor and stimulate insulin-like growth factor binding protein-2 secretion. MAC-T cells provide a model system to study mechanisms that regulate local insulin-like growth factor-I bioactivity.

• 한국수산과학회지
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• 제29권2호
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• pp.150-156
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• 1996

양식 넙치, Paralichthys olivaceus를 실험어로 하여 동물 성장인자중의 하나인 insulin-like growth factor-I (IGF-I)의 함량을 검토하였다. 넙치의 혈액중에 존재하는 IGF-I의 양은 47ng/m1이고, 절식을 할 경우 식이를 섭취한 것에 비해 약 $15\%$ 감소하였으며, 운동에 의해서는 약 $13\%$의 감소를 보였다. 혈액중 IGF-I의 농도는 어체의 크기에 따라서도 영향이 있음을 알수 있었다.

• 한국수산과학회지
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• 제31권5호
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• pp.774-778
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• 1998

동물성장인자인 insulin-like growth factor-I (IGF-I)이 조피볼락의 성장 및 혈액중에 존재하는 IGF binding proteins (IGFBPs)에 미치는 영향을 검토하기 위하여 human recombinant IGF-I을 투여하여 분석한 결과, 절식중의 조피볼락 체중은 IGF-I 투여군이 생리식염수만 투여한 대조군 보다 체중 증가효과가 있었으며, 혈액중 glucose농도는 IGF-I의 투여군이 혈당저하효과를 나타내었다. 그리고 혈액중 IGFBP-3는 IGF-I투여군에서 증가하였으며, IGFBP-1은 감소하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권5호
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• pp.363-369
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• 2005

Purpose: To determine the role of Insulin-like Growth Factor-I (IGF-I) in the regulation of Vascular Endothelial Growth Factor (VEGF) expression in MG-63 cells and then to find the mechanism b which this regulation occurs. Materials and methods: MG-63 cells were grown to confluence in 60-mm dishes. To determine the effects of IGF-I on expression of VEGF mRNA according to time and concentration, the cells were treated with 10 nM IGF-I, following isolation of total RNA and Northern blot analysis after 1, 2, 4, 8, 12, 24 hours and after 2 hours of treatment with 0.5, 2, 10, 25, 50 nM IGF-I respectively, isolation of total RNA and Northern blot analysis were followed. To determine the mechanism of action of IGF-I, inhibitors such as hydroxyurea $(76.1\;{\mu}g/ml)$, actinomycin D $(2.5\;{\mu}g/ml)$, cycloheximide $(10\;{\mu}g/ml)$ were added 1 hour after treatment of 10 nM IGF-I. Results: 1. the expression of VEGF mRNA was increased with treatment of IGF-I. 2. The expression of VEGF mRNA was increased according to time-and concentration dependent manner of IGF-I. 3. The effect of IGF-I was decreased by hydroxyuera, actinomycin D, but not by cycloheximide. Conclusion: IGF-I regulate the expression of VEGF mRNA in the level of DNA synthesis and transcription. These results could suggest that IGF-I plays an important role in angiogenesis in the process of new bone formation and remodeling.

• 대한수의학회지
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• 제46권2호
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• pp.97-105
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• 2006

All-trans retinoic acid (AtRA) induces growth inhibition and apoptosis in a variety of tumer cells, including MCF-7 cells. Insulin-like growth factors (IGFs) system has been reported to be associated with the development of cancer. Although MCF-7 cell with AtRA is to be the major stimulus for the cell growth and apoptosis, the mechanism of insulin-like growth factor-I (IGF-I)/insulin-like growth factor binding protein-3 (IGFBP-3) system remains to be elucidated. Thus, this study was conducted to the effect of AtRA on the gene expression and level of IGF-I and IGFBP-3. In addition, we investigated the involvement of PKC-${\delta}$ on the IGF-I and IGFBP-3 secretion in MCF-7 cell. AtRA(${\geq}10^{-7}M$) decreased the IGF-1 secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cells. Especially, the treatment of AtRA at 72 hours caused a significant reduction in the IGF-I secretion and mRNA expressions but increment in IGFBP-3 secretion and mRNA expressions (p < 0.05). $10^{-7}M$ AtRA activated PKC-${\delta}$ that is one among PKC-$\iota$, ${\alpha}$, ${\lambda}$ and ${\delta}$ in MCF-7 cell. Rotllerin, a PKC-${\delta}$ inhibitor, blocked AtRA-induced inhibition of the IGF-I and mRNA expressions, and increase of lGFBP-3 and mRNA expressions in MCF-7 cell. Together, AtRA inhibited the IGF-I secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cell. Furthermore, AtRA-induced alteration of IGF-I, IGFBP-3 secretion, and the gene expressions were mediated via PKC-${\delta}$ activity.

• 대한수의학회지
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• 제37권2호
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• pp.409-416
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• 1997

Bovine theileriosis caused by Theileria sergenti is the tick-borne intraery- throcytic piroplasmosis, that occurs in most regions of Korea. It results in severe economic losses on a farm caused by anemia, milk production loss, abortion and death. This study was undertaken to confirm the effects of the growth hormone and the insulin-like growth factor-I which are associated in the growth of cattle infected by T sergenti. The blood of one hundred and twenty ten-month Holstein was collected and the prepared blood smear was stained with acridine orange to investigate their parasitemia. And the hematological profiles were observed. According to the value of the hematocrit, they were categorized into four groups : Group 1 was under 20 percent, groups 2 and 3 were from over 21 to under 30 percent and from over 31 to under 35 percent and group 4 was over 36 percent. As the value of the hematocrit decreased, parasitemia(%) in erythrocytes was observed to increase(Y=-1.064X + 30.537, r=0.660). The amounts of the growth hormone and the insulin-like growth factor-I in the serum were measured by the radioimmunoassay. The growth hormone in serum of the group 1, group 2, group 3 and group 4 were observed as $0.238{\pm}0.043nmol/l$, $0.21{\pm}0.024nmol/l$, $0.366{\pm}0.035nmol/l$ and $0.646{\pm}0.223nmol/l$, respectively. The quantitative of the insulin-like growth factor-I in the same groups were observed also as $209.686{\pm}18.94ng/ml$, $250.9{\pm}12.609ng/ml$, $279.3{\pm}8.883ng/ml$ and $365.9{\pm}22.45ng/ml$, respectively. It can be concluded that the growth hormone and the insulin-like growth factor-I were observed to decrease in severe anemia due to theileriosis.

• KSBB Journal
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• 제17권3호
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• pp.283-289
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• 2002

Insulin-like growth factor-I(IGF-I)은 성장호르몬의 여러 가지 성정촉진 작용을 매개하는 분열 유발성 폴리펩티드이며, 조직의 수선과 재생, 창상치유 및 골대사와 같은 과정들에서 중요한 역할을 하는 것으로 알려져 있고, 비교적 여러 조직에서 발현되고 있는 IGF-I 유전자의 전사조절에 대한 정확한 분자적 기전과 호르몬 및 대사 상태가 그것을 어떻게 조절하는지 아직 밝혀져 있지 않다. 쥐를 절삭시키므로써 대사 상태를 변조시켰을 때, 간 조직내 IGF-I mRNA의 발현에 미치는 절식의 영향을 살펴보기 위하여 solution hybridizatioon/RNase protection 방법으로 분석 하였다. IGF-I의 exon 1 및 exon 2에 의하여 encode된 tran-scripts 모두가 감소된 결과를 얻었고, 이러한 감소는 전사 수준에서 일어난 것으로 nuclear run-on 분석에 의하여 확인하였다. 또한 절식시킨 쥐에서 IGF-I mRNA의 양을 조절하는 cia-acting elements를 IGF-I 유전자의 5'-flanking 지역과 exon 1과 econ 2에서 밝히고자 절식시킨 쥐의 신선한 간조직에서 핵 추출물을 얻어 IGF-I의 여러 가지 DNA fragments와 반응시켜 DNase I protection 분석을 한 결과, IGF-I 유전자의 주요한 전사 개 시점으로부터 downstream에 있는 sequences가 절식으로 변조시킨 대사상태에서 IGF-I의 발현 조절에 중요하며 이곳에는 전사인자인 C/EBP family의 isoform들을 포함한 간조직에 풍부하게 존재하는 여러 전사인자들이 결합할 것으로 제안하였다.

• 대한수의학회지
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• 제39권5호
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• pp.938-944
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• 1999

The insulin-like growth factor-I(IGF-I) is an important metabolic factor involved in cell growth and metabolism. Although secretion of IGF-I in rat liver is regulated by growth hormone, the effects of forskolin, adenylate cyclase activator, on secretion of IGF-I have not been reported. Therefore, a modified perfused rat liver model was used to investigate the regulatory effects of forskolin on IGF-I secretion in this experiment. The results were summerized as follows : 1. Modified perfused rat liver model was not changed to aspartate aminotransferase(AST), alanine aminotransferase(ALT) and lactic dehydrogenase(LDH) secretion in time. 2. The IGF-I secretion in hepatic cell was increased by forskolin($10^{-5}$, $10^{-6}$ and $10^{-7}M$) in a dose-dependent manner as compared with those of the controls, and significantly increased by $10^{-5}$ and $10^{-6}$ forskolin(p < 0.05). 3. Secretion of glucose in hepatic cell significantly was decreased by $10^{-5}$ forskolin as compared with those of controls(p < 0.05). These results suggest that forskolin may be involved in the regulation of IGF-I secretion in the perfused rat liver.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1121-1126
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• 2000

Daily variation in the serum concentrations of insulin and insulin-like growth factor-I and in the plasma concentrations of thyroxine and triiodothyronine were evaluated in ewes fed 30%, 100% and 200% of theoretical maintenance energy requirements. The single daily meal has had significant effects (p<0.05) on almost all profiles. In general, serum or plasma hormone concentrations have increased after the meal, in particular at the two higher levels of energy intake. In the group submitted to the lowest level of energy intake, the consequences of the meal on circulating levels were almost imperceptible. The effects of feeding levels on serum or plasma concentrations have widely varied among hormones, not showing any objective pattern or relationship. Because these variations may affect the interpretation of these blood indicators, knowledge of daily profiles and of the effect of feed level must be considered. In order to maximize the diagnostic value of those indicators, the most suitable times for blood collection seem to be 16 h after the meal and (or) just before the meal. The collection 16 h after the meal apparently allows the characterization of a relatively steady metabolic state, intermediate between the close effects of food intake and the final phase of the intensification of body reserves mobilization. The collection just before the meal will give a good indication of the level of activity of those mobilization mechanisms.

• 한국식품영양과학회지
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• 제28권3호
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• pp.685-690
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• 1999

The insulin like growth factors(IGFs) are bound to several binding proteins(IGFBPs) that appear to regulate IGF transfort, receptor binding, and its action. The concentrations of these peptides are regulated by quantity and nutritional quality of dietary proteins. The aim of this study was to compare the effects of two diets, which differed in their protein source, Carassius carassius(CC), Carassius carassius hot water extract(CCHE), for 4 weeks. Body weight was significantly increased in the CC group(74.14$\pm$12.00 to 266.31$\pm$36.62g; p<0.01). Likewise, IGF I concentration of CC group(101.76$\pm$15.90 ng/ml) was significantly higher than that of CCHE group(38.50$\pm$ 11.20ng/ml; p<0.05). By western immunoblot analysis, especially IGFBP 1, 2 levels are increased, whereas IGFBP 3 level was de creased in CCHE group. After extraction of browning material from each samples, the extractive was filtered and absorbance at 420nm was measured. The absorbance of CCHE group was significantly higher than that of CC group. These results suggest that IGF I can be employed as an index of protein metabolism, particulary as a simple index in the assessing the status of protein nutrition.