• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1451-1457
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• 2016

A comparative study was performed to investigate the efficacy of KiFAY as a feed additive on performance parameters, thyroid, and pancreatic hormone levels in broilers. Ninety birds (Vencobb 400) were randomly divided into three groups viz., Control (no DL-methionine supplementation), Treatment1 (containing added DL-methionine) and Treatment 2 (containing KiFAY and without DL-methionine supplementation). The performance parameters (weekly body weight, body weight gain, feed intake, and feed consumption ratio) were recorded and calculated during the whole study of 4 weeks. Analyses of insulin and insulin-like growth factor (IGF 1), triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were performed at the end of the study. The results show that birds on supplementation of KiFAY performed significantly (p<0.001) better than other treatments. The weekly body weight, body weight gain, feed in-take and feed consumption ratio improved in KiFAY treated birds. The study found an increase in insulin and IGF1 levels (p<0.001) in KiFAY compared with the other treatments. Serum T3, T4, and TSH levels in the Treatment 2 were higher than other treatments (p<0.001). The KiFAY supplementation was able to improve performance with associated responses at a hormonal level in broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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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.

• KSBB Journal
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• v.17 no.3
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• pp.283-289
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• 2002

The present study was aimed at investigating the metabolic regulation of insulin-like growth factor-I(IGF-I) expression in fasting animals. The expression of IGF-I gene was determined by a solution hybridization/RNase protection assay using total RNA from control, 4d-fasting, and 2d-fasting-refed rats. The levels of IGF-I transcripts were reduced in 4d-fasting than in control by decreasing its transcriptional rate, which was measured through nuclear nun-on assay. DNase I footprinting, which was performed using nuclear extracts from fasting rat, demonstrated protein binding to a sequence that extended from +179 to +210 (termed region B). These data suggest that the expression of IGF-I is transcriptionally regulated through DNA-liver enriched protein binding in a sequence which is located downstream from major transcription initiation site of IGF-I gene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.493-499
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• 2000

골감소증 환자의 혈청중에 존재하는 IGFBP-5의 존재와 변화를 검토한 결과, 골감소즈 환자에서는 정상 대조군에 비해 IGFBP-5가 감소하였는데 이 변화는 IGFBP-5의 분해효소가 작용하기 때문인 것으로 나타났다. IGFBP-5에 작용하는 단백질분해효소 저해제중 metallo계인 EDTA 및 1,10-phenanthroline과 seriner계인 aprotinin, heparin, heparin cofactor 2(HC2), heparine+HC2가 IGFBP-5에 대해 저해효과가 크므로 metalloprotease이면서 serine protease의 성질을 가지는 효소들이 IGFBP-5에 작용하였다. IGF-I과 IGF-II 그리고 insulin은 효소 활성에 아무런 영향이 없었다. IGFBP-5의 zymography에서 정상인과 골감소증 환제어서 180 kDa 크기의 band가 나타났고, gelatin zymography에서 정상 대조군의 경우 66 kDa과 97 kDa 정도의 band가 확인되었고 골감소증 환자의 경우는 69 kDa의 band가 확인되었다.

• 대한생식의학회:학술대회논문집
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• 1995.12a
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• pp.70.1-70.1
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• 1995

• BMB Reports
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• v.32 no.3
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• pp.266-272
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• 1999

The insulin-like growth factor (IGF) system consisting of IGF-I, IGF-II, IGF-receptors, and IGF-binding proteins (IGFBP) regulates the proliferation of a variety of cancer cell types. To examine whether a decrease in endogenous IGFBP-3 stimulates proliferation or inhibits differentiation, Caco-2 cells, a human colon adenocarcinoma cell line, were stably transfected with an anti-sense IGFBP-3 expression construct or pcDNA3 vector as control. Accumulation of IGFBP-3 mRNA and secretion of IGFBP-3 into serum-free conditioned medium, 9 days after plating, were significantly lower in Caco-2 cell clones transfected with anti-sense IGFBP-3 cDNA compared to the controls. The anti-sense clones grew at a similar rate to the controls for 8 days after plating, but achieved a higher final density between days 10 and 12. The levels of sucrase-isomaltase mRNA, a marker of enterocyte differentiation of Caco-2 cells, were lower in the anti-sense clones examined on day 9. In conclusion, proliferation of Caco-2 cells can be stimulated by lowering endogenously-produced IGFBP-3.

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.151-152
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• 2003

• Korean Journal of Veterinary Research
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• v.39 no.5
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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.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.731-737
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• 2000

Objective : Growth factor receptors on the tumor cells are known to be expressed highly allowing the tumor cells to bind growth factors to stimulate cellular division. Immunotoxin therapy is one of the novel approaches to the primary malignant brain tumor, and expression of cell-surface receptor is essential for the immunotoxin to have specific anti-tumor activity. Despite promising cytotoxic activity of immunotoxin, tumor responses are not curative on clinical trials, and additional studies are needed regarding various factors influencing the efficacy of the immunotoxin. The purpose of this study is to detect the expression of various growth factor receptors on brain tumor cell lines which are going to be used in these studies. Materials and Methods : The authors detected transferrin receptor(TR), insulin-like growth factor-1 receptor(IGF-1R), and interleukin-4 receptor(IL-4R) on medulloblastoma cell line(Daoy) and glioblastoma cell lines(U373 MG and T98 G) by flow cytometric analysis. Results : TR was expressed on Daoy, U373 MG, and T98 G. IGF-1R was expressed on Daoy and U373 MG, but not on T98 G. IL-4R was expressed on all cell lines tested. Conclusion : The transferrin and interleukin-4 receptors might be good targets for immunotoxin therapy. The results should be considered in additional in vitro and in vivo studies regarding immunotoxin and in establishing the proper treatment model of the immunotoxin therapy including selection of the adequate immunotoxin.