• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1224-1231
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• 2007

Insulin-like growth factor-I (IGF-I) and IGF-II have structure like insulin. In contrast to insulin, however, the bioavaility of IGFs is modulated by the IGF-binding protein (IGFBPs). Each of IGFBPs was different with molecular masses, biological characteristics, and immunological properties.. Human fibroblasts secrete IGFBPs that can modify IGF-I action. In diabetes mellitus, the most study of IGF systems have been investigated in insulin-dependent diabetes mellitus, non-insulin-dependent diabetes mellitus, and streptozotocin-in-duced animals in vivo. Recently, a little research regarding the IGFs system has been proposed in por-tion of cell in vitro. In this study, effects of low or high glucose condition on IGFBP-5 in GM10 was investigated. By western blotting analysis, IGFBP-5 level decreased in cells cultured at high glucose, but IGFBP-5 level of mRNA didn't change. IGFBP-5 protease that cleaves IGFBP-5 in conditioned me-dium had was inhibited by EDTA and heparin, like serine protease and metalloprotease. Furthermore, the protease activity was increased in high glucose cultivated condition. In results of gelatin zymog-raphy, molecular weight of proteolytic metalloenzymes was indentified 69-kDa and protease activity was increased in time-dependent manner. Although the mechanism has yet to be determined, IGFBP-5 proteolysis in GM10 cells cultured with high glucose may increase effects of IGFs to decrease the glu-cose level through dissociation of IGFs from IGFBPs. Therefore, we suggest that IGF- I and IGFBPs could be potential models in study of pathophysiology such as diabetes mellitus.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.99-99
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• 2001

The acid-labile subunit (ALS) associates with insulin-like growth factor (IGF)-I or -II and IGF binding protein-3 (IGFBP-3) to form a 150-kD complex in the circulation. This complex is thought to regulate the serum IGFs by restricting them in the vascular system and promotes their endocrine actions. Little is known about how ALS binds to IGFBP3, which connects the IGFs to ALS. Xenopus oocyte was utilized to study the function of ALS in assembling IGFs into the ternary complexes. Xenopus oocyte was shown to correctly translate in vitro transcribed mRNAs of ALS and IGFBP3. IGFBP3 and ALS mRNAs were injected in mixture and their products were immunoprecipitated by antisera against ALS and IGFBP3. Contrary to the traditional reports that ALS interacts only with IGF-bound IGFBP3, this study shows that ALS is capable of forming a binary complex with IGFBP3 in the absence of IGF. When cross-linked by disuccinimidyl substrate, band representing ALS-IGFBP3 complex was evident on the PAGE. IGFBP3 movement was monitored according to the distribution between the hemispheres. Following a localized translation in the vegetal hemisphere, IGFBP3 was shown to remain in the vegetal half in the presence of ALS. Different from wild type IGFBP3, however, mutant IGFBP3 freely diffused into the animal half despite the presence of ALS. Taken together, this study suggests that ALS may play an important role in sequestering IGFBP3 polypeptides via the intermolecular aggregation. Studies using this heterologous model will lead to a better understanding of the IGFBP3 and ALS assembling into the ternary structure and circulating IGF system.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1244-1251
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• 2008

The aim of the present study was to delineate the expression and secretion of insulin-like growth factor (IGF) system components by pig liver cells. Hepatocytes were prepared from 3-wk-old weanling piglets following a two-step collagenase perfusion procedure, after which the cells were incubated for 24 or 48 h at a density of $2{\pm}10^5$ cells per 35-mm dish in 2-ml Williams' medium E. The cells were found to express the genes encoding IGF-I, IGF-binding proteins (IGFBPs)-2 and -3 and acid-labile subunit (ALS) by reverse transcription-polymerase chain reaction (RT-PCR) following the culture. However, IGF-I was localized to hepatocytes by immunohistochemical analysis, whereas IGFBP-3 was localized to endothelial cells, but not to hepatocytes. This indicated that the IGFBP-3 gene expression detected by RT-PCR was likely to have been contributed by unidentified non-parenchymal cells that had not been removed during the hepatocyte preparation. The conditioned culture medium (CCM) of the cells contained immunoreactive IGF-I and IGF-II, with the latter being seven-fold more abundant than the former. The CCM also contained 43-, 40-, 34-, 31-kDa doublet and 26-kDa IGFBPs as examined by Western ligand blotting. The 40-, 34- and 31-kDa doublet IGFBPs were approximately three-fold as abundant as the 43- and 26-kDa IGFBPs. Moreover, the 43- and 40-kDa doublet and the 34-kDa IGFBPs were immunoprecipitable with IGFBP-3 and IGFBP-2 antibodies, respectively. Overall, these results are similar to those known in the rat, which suggests that the IGF system components are likely to be expressed and secreted in pig liver in a manner similar to that in rat liver.

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.99.2-100
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• 2003

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.172.2-172
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• 1999

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 2001.04a
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• pp.68-68
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• 2001

No Abstract, See Full Text

• Journal of Yeungnam Medical Science
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• v.28 no.1
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• pp.77-83
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• 2011

Non-islet cell tumor-induced hypoglycemia (NICTH) is associated with mesenchymal tumor types, including hemangiopericytoma, fibrosarcoma, mesothelioma, and neurofibroma, as well as carcinoma of the liver, adrenal glands, and kidneys. Non- islet cell tumors induce hypoglycemia by overproducing an abnormal form of insulin-like growth factor II (IGF m. Complete removal of the tumor or reduction of the tumor mass is a successful therapeutic strategy in cases of NICTH. However, if the tumor re-grows, curative resection is nearly impossible, and hypoglycemia occurs repeatedly. Glucocorticoids are effective in terms of long-term relief from hypoglycemia through promotion of gluconeogenesis in the liver, tumor suppression, production of 'big'-IGF-II, and correction of the attendant biochemical abnormalities involving the growth hormone (GH)-IGF axis. We found that administration of corticosteroid therapy to a patient suffering from NICTH resulted in improvement of hypoglycemia associated symptoms.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.15-22
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• 2000

Objective: To elucidate the location of leptin and receptors of ovary specimens obtained from patients undergoing hysterectomy by immunohistochemical staining and to determine the effect of leptin on the steroidogenesis of cultured granulosa cells. Method: In the culturing process of the granulosa cells, FSH (1 IU/ml)and leptin (50 ng/ml), IGF-I (50 ng/ml) was administered to each study group (Group I: FSH; Group II: FSH, leptin; Group III: FSH, IGF-I; Group IV: FSH, IGF-I, leptin), and the levels of estradiol, progesterone, androstenedione in the culture media was measured by radioimmunoassay. Statistical analysis was conducted by one-way ANOVA with Scheffe test. Results: The results showed that leptin and leptin receptors were both found to be strongly stained in granulosa and theca cells, and also in some interstitial cells. Leptin receptors were also observed in cultured granulosa cells. While there was no statistically significant difference in the androstnedione concentrations between the groups, estradiol concentrations was significantly decreased in Group IV ($2202.0{\pm}151.14$ pg/ml) compared to Group III ($2859.0{\pm}122.6$ pg/ml), and progesterone concentrations were also significantly decreased in Group II($4696.3{\pm}190.6$ ng/ml) and Group IV ($4517{\pm}206.78$ ng/ml) compared to Group III($5546.0{\pm}179.5$ ng/ml). Conclustion: The study result of this study suggest that leptin is directly involved in the regulation of ovarian functions, in particular steroidogenesis.

• Journal of Nutrition and Health
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• v.28 no.10
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• pp.1031-1039
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• 1995

Dietary mehaden oil enhances mucosal hyperplasia that normally occurs after massive small bowel resection. In contrast, dexamethasone and aspirin inhibit the adaptation response. In order to gain insight on the mechanism of these effects, male Sprague-Dawley rats weighing approximately 150gram were randomly divided into two groups and fed diet containing either 15% safflower oil or 14% menhaden oil and 1% safflower oil. Ten days later they were subjected to 70% jejunoilear resection. Immediately after surgery each group was further divided into two groups and receive either vehicle or 125ug/kg/day dexamethasone subcutaneously. All animals were sacrificed seven days after the surgery, and the remaining intestine was removed and divided at the anastomotic site. Dexamethasone, which decreased gut hyperplasia in both dietary groups, decreased both serum IGF-I levels and ileral PGE2 synthesis. Menhaden oil enhanced gut hyperplasia, but did not increase IGF-I or IGF-II levels in serum. PGE2 synthesis was lower in the ileum of menhaden oil-fed rats compared to that of safflower oil-fed rats. The effects of menhaden oil on adaptation did not apper to be mediated either through IGFs or PGE2 synthesis. Other factors could have played a role in enhancing adaptation following menhaden oil feeding.

• Journal of Embryo Transfer
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• v.17 no.3
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• pp.227-234
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• 2002

This study was performed to investigate the improvement of the pregnancy rate of Al or clone embryo transfer on hCG administration in Korean Native heifer. A total of 42 heifers were treated with control, CIDR(withou E2 capsule). hCG after 7 day of hi, the pregnancy rate were spewed 53, 46, 71%. These results were significant different among the treatments(P<0.05). When the hCG were adminstrated at cloned embryo transfer, pregnanacy rate were control, hCG 5.8%, 10.4% respectively and there was no significant different between treatments. Plasma P4 concentration of hCG treatment in heifers were 3 times higher than control on 13~16 day after heat. After this, plasma P4 concentration of CIDR and hCG treated heifers were kept the 2~3 times levels. IGF-I concentration were showed no differences between pregnancy and non-pregnancy. hOG and CIDR. IGF-II concentration were revealed the differences between pregnancy and non-pregnancy in CIDR group but there was no differences in hCG administration group. Plasma cortisol were high at heat and 16 day after heat and CIDR treated group was higher than the other group. These results suggest that hCG administration was improve the pregnancy rates on Al and cloned ET, accompanying the incline of P4 concentration.