• Clinical and Experimental Reproductive Medicine
• /
• v.26 no.3
• /
• pp.483-490
• /
• 1999

Objectives: Polycystic ovary syndrome (PCOS) has the feature of excessive LH, hyperandrogenism and disturbance of folliculogenesis. Also, insulin, IGF-I and IGFBP-l are involved in the pathogenesis of PCOS. Various surgical and medical therapies have been used and the action mechanisms are related to the endocrine effect. Laparoscopic ovarian electrocautery or laser vaporization is effective in the restoration of ovulation and normal menstrual cycle with minimal invasive procedure especially in the patients resistant to medical therapy. Clomiphen citrate (CC) is used for the ovulation induction in pcas and the resistance is known to be related to insulin, IGF-I, IGFBP-l levels. This study was performed to evaluate the effect of the laparoscopic laser vaporization on the levels of LH, FSH, testosterone, IGF-I and IGFBP-l and on the ovarian response to clomiphen citrate in patients with CC-resistant PCOS. Materials and Methods: The fasting basal serum LH, FSH, testosterone, IGF-I and IGFBP-l level were measured in 10 PCOS patients with CC-resistance and 7 normal controls with regular menstrual cycle. In PCOS, after laparoscopic $CO_2$ laser vaporization, endocrine levels were measured in 1 week interval for 4 weeks and then compared with preoperative levels. Results: In PCOS group, mean serum LH/FSH ratio, testosterone, IGF-I levels were higher and IGFBP-l level was lower than control. LH/FSH ratio decreased from $2.51{\pm}0.67$ to $1.7{\pm}0.6$ (p<0.05) in 2 weeks, to $0.56{\pm}0.2$ (p<0.01) in 3 weeks and to $1.41{\pm}0.3$ (p<0.01) in 4 weeks after operation. Testosterone level decreased from $1.51{\pm}0.82ng/ml$ to $0.65{\pm}0.34ng/ml$ (p<0.05) in 2 weeks, to $0.56{\pm}0.67ng/ml $(p<0.01) in 3 weeks after operation. IGF-I level also decreased from $436{\pm}47.5{\mu}g/l$ to $187{\pm}38{\mu}g/l$ (p<0.0l) in 1 week, to $167{\pm}42{\mu}g/l$ (p<0.01) in 2 weeks, $179{\pm}55{\mu}g/l$ (p<0.01) in 3 weeks and to $120{\pm}43{\mu}g/l$ (p<0.01) in 4 weeks after operation. IGFBP-l level showed no significant change. In 8 of 10 PCOS patients, ovulation was induced with low dose clomiphen citrate. Conclusion: Laparoscopic $CO_2$ laser vaporization restores normal menstrual cycle and ovulation through endocrine effect of decreasing LH/FSH ratio, testosterone and IGF-I level and increases the response to CC. Therefore it is useful for restoration of normal menstruation and induction of ovulation in CC resistant PCOS patients.

• Korean Journal of Human Ecology
• /
• v.9 no.1
• /
• pp.81-88
• /
• 2006

IGFs and IGFBPs have an important role in controlling glucose homeostasis. This study was conducted to investigate the changes of insulin-like growth factor(IGF)-I. IGF-II and IGF binding proteins (IGFBPs) on fasting and postprandial state in Korean diabetes, Twenty eight healthy subjects and fifty seven diabetic patients participated in this study. The healthy subjects were not knowingly suffered from any disease and were not receiving any medical treatment, and diabetic subjects were undergo medical treatment, continuously. Weight and height were measured and body mass index (BMI) was calculated as weight (kg) divided by the square of height (m2). Blood pressure was measured. Plasma lipid profiles were analyzed by enzymatic methods, plasma Insulin and glucose levels were measured in fasting and postprandial state, respectively. The levels of serum IGFs and IGFBP-3 were measured by radioimmunoassay (RIA). The levels of glucose and insulin were significantly higher in diabetes than normal subjects on fasting as well as postprandial state (p<0.0l). The levels of IGF-I was significantly lower in diabetes than normal subjects, however in postprandial state, there was no significant difference between diabetes and control subjects, The levels of IGF-II were significantly lower in diabetes than control subjects both fasting and postpradial state, The level of IGFBP-3 were not significantly different between diabetes and normal subjects. Fasting IGF-I, IGF-II and IGFBP-3 levels were positively correlated with those levels on postprandial state, fasting IGe levels of IGF-I levels were positively correlated with fasting insulin levels, and postprandial IGF-I levels were positively correlated with fasting glucose, postprandial insulin and postprandial insulin levels, plasma triglyceride levels were correlated with plasma triglyceride levels. The IGFBP-3 levels were not correlated with IGF components, glucose, insulin and plasma lipids, These results demonstrate that in diabetes, the components IGF-I/IGFBPs system were significantly correlated with plsma glucose and insulin levels both fasting and postprandial state.

• Clinical and Experimental Pediatrics
• /
• v.48 no.3
• /
• pp.298-305
• /
• 2005

Purpose : We performed this study to evaluate the mean serum levels of insulin-like growth factor (IGF)-I, insulin-like growth factor binding protein(IGFBP)-2 and IGFBP-3 in healthy Korean children according to age and sex. Methods : Ninety two healthy children, consisting of 42 boys and 50 girls, were classified into five groups according to age : neonate; infancy; early childhood; late childhood; and adolescence. We measured serum levels of IGF-I, IGFBP-2 and IGFBP-3 by enzyme-linked immunosorbent assay(ELISA) and analysed the serum levels according to sex and age group. Results : For boys, the mean serum levels of IGF-I(ng/mL) in neonate, infancy, early childhood, late childhood and adolescence were $41.1{\pm}3.6$, $70.9{\pm}33.7$, $103.5{\pm}97.2$, $89.8{\pm}46.5$ and $51.4{\pm}27.8$, respectively. Those of IGFBP-2(ng/mL) were $8.2{\pm}3.4$, $5.8{\pm}0.4$, $9.3{\pm}4.0$, $9.5{\pm}1.1$ and $7.0{\pm}0.5$, respectively. Those of IGFBP-3(ng/mL) were $559.2{\pm}215.2$, $1,333.3{\pm}692.5$, $2,254.6{\pm}1,513.8$, $2,447.1{\pm}1,464.2$, $1,533.6{\pm}807.4$, respectively. For girls, the mean serum levels of IGF-I(ng/mL) according to five age groups were $53.3{\pm}9.5$, $99.3{\pm}45.8$, $69.6{\pm}51.1$, $106.2{\pm}67.0$ and $145.1{\pm}127.8$, respectively. Those of IGFBP-2 (ng/mL) were $9.1{\pm}7.4$, $5.3{\pm}0.9$, $6.9{\pm}2.0$, $10.5{\pm}3.0$ and $7.9{\pm}1.3$, respectively. Those of IGFBP-3(ng/mL) were $858.2{\pm}433.4$, $1,834.8{\pm}851.3$, $1,404.3{\pm}570.2$, $2,203.5{\pm}899.4$ and $2,029.3{\pm}1,316.7$, respectively. There were significant positive correlations observed between IGF-I and IGFBP-3 levels(r=0.589, P=0.000). Conclusion : IGF-I and IGFBP-3 levels increased as children get older. The peak level of IGFBP-3 was observed in late childhood for both boys and girls, suggesting a current trend of children reaching peak growth velocity before adolescence. The IGFBP-2 level was higher in neonates compare to infancy, suggesting that IGFBP-2 is an important substance for fetal growth.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.1
• /
• pp.147-154
• /
• 2014

This review focuses on modulation of growth hormone (GH) and its downstream actions on periparturient dairy cows undergoing physiological and metabolic adaptations. During the periparturient period, cows experience a negative energy balance implicating that the feed intake does not meet the total energy demand for the onset of lactation. To regulate this metabolic condition, key hormones of somatotropic axis such as GH, IGF-I and insulin must coordinate adaptations required for the preservation of metabolic homeostasis. The hepatic GHR1A transcript and GHR protein are reduced at parturition, but recovers on postpartum. However, plasma IGF-I concentration remains low even though hepatic abundance of the GHR and IGF-I mRNA return to pre-calving value. This might be caused by alternation in IGFBPs and ALS genes, which consequently affect the plasma IGF-I stability. Plasma insulin level declines in a parallel manner with the decrease in plasma IGF-I after parturition. Increased GH stimulates the lipolytic effects and hepatic glucose synthesis to meet the energy requirement for mammary lactose synthesis, suggesting that GH antagonizes insulin-dependent glucose uptake and attenuates insulin action to decrease gluconeogenesis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.7
• /
• pp.1135-1141
• /
• 1999

A large number of investigations have shown that changes in nutritional condition affect endocrine status in avian species. Herein, recent findings including novel peptides discovered by the development of the techniques in the field of molecular biology have been reviewed. The insulin-like growth factors (IGF-I and IGF-II) found in chickens have been characterized and shown to be 70 and 66 amino acid polypeptides, respectively. Plasma IGF-I level is very responsive to nutrition, Le. varying dietary proteins and energy intakes, and food restriction. Plasma IGF-II concentration is altered by nutritional deprivation to a much smaller extent than plasma IGF-I concentration. Almost all of the serum and tissue IGFs are found in a complex composed of IGF and IGF-binding protein (IGFBP). In the chicken plasma, the major IGFBP differs from that in mammalian plasma. The proglucagon mRNA encodes glucagon and two glucagon-like peptides (GLP-I and GLP-2). The intracerebroventricular administration of GLP-l strongly decreased food intake of chicks, and it was indicated that the inhibition of food intake by GLP-l was associated with neuropeptide Y, which is one of the neurotransmitters reported to enhance food intake.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.242-250
• /
• 2011

Although insulin-like growth factor-I (IGF-I) and androgen receptor (AR) coactivators are well known effectors of skeletal muscle, the molecular mechanism by which signaling pathways integrating AR coactivators and IGF-I in skeletal muscle cells has not been previously examined. In this study, the effects of IGF-I treatment on the gene expression of AR coactivators in the absence of AR ligands and the roles of the p38 MAPK and ERK1/2 signaling pathways in IGF-I-induced AR coactivators induction were examined. C2C12 cells were treated with 250 ng/ml of IGF-I in the presence or absence of specific inhibitors p38 MAPK (SB203580) or ERK1/2 (PD98059). Treatment of C2C12 cells with IGF-I resulted in increased in GRIP-1, SRC-1, and ARA70 protein expression. The levels of GRIP-1, SRC-1, and ARA70 mRNA were also significantly increased after 5min of IGF-I treatment. IGF-I-induced AR coactivator proteins were significantly blocked by pharmacological inhibitors of p38 MAPK and ERK1/2 pathways. However, there was no significant effect of those inhibitors on IGF-I-induced mRNA level of AR coactivators, suggesting that AR coactivators are post-transcriptionally regulated by IGF-I. Furthermore, the present results suggest that IGF-I stimulates the expression of AR coactivators by cooperative activation of the p38 MAPK and ERK1/2 pathways in C2C12 mouse skeletal muscle cells.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.10
• /
• pp.1508-1513
• /
• 2006

Myostatin (MSTN) and insulin-like growth factors (IGFs) are a known inhibitor and stimulators of proliferation and differentiation of muscle cells, respectively. The present study was performed to investigate the relationship of MSTN-induced growth inhibition to expression of the IGF system components and myogenin, a muscle cell-specific transcription factor, in rat L6 myoblasts. The L6 cells transfected with a green fluorescent protein-MSTN plasmid expression construct had a 47% less cell number than mock-transfected cells after 3-d serum-free culture, accompanied by delayed differentiation which was suggested by inhibited aggregation of cells. Moreover, cells transfected with the expression construct had decreased expression of IGF-II and myogenin genes, but not IGF-I or its receptor genes, as examined by reverse transcription-polymerase chain reaction. The reduced mitosis of the L6 cells transfected with the MSTN-expression construct increased following an addition of either IGF-I or IGF-II to the culture medium, but not to the level of mock-transfected cells. By contrast, myogenin gene expression in these cells increased after the addition of either IGF to the level of mock-transfected cells. Collectively, these results suggest that the inhibitory effect of MSTN on L6 cell proliferation and differentiation is likely to be partly mediated by serially suppressed expression of IGF-II and myogenin genes, not IGF-I gene.

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

• Microbiology and Biotechnology Letters
• /
• v.42 no.2
• /
• pp.139-144
• /
• 2014

This study examined the efficacies of Cynanchum wilfordii and Phlomis umbrosa extracts on serum insulin like growth factor-I (IGF-I) and bone growth by raising rats in vivo. C. wilfordii and P. umbrosa extracts significantly increased serum IGF-I by 42% and 22% than the control, respectively. Treatment with ${\alpha}$-amylase when manufacturing these extracts remarkably increased the concentration of IGF-I by 63% and 36% above the control, respectively. This meant that these extracts, especially ${\alpha}$-amylase treated extracts, maintained a higher level of IGF-I secretion in the treated groups. In addition, increases of 6% in femur length were found after 8 weeks of oral administration with these extracts. These results indicate that C. wilfordii and P. umbrosa extracts have beneficial effects on bone growth via IGF-I.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.6
• /
• pp.862-867
• /
• 1999

The present study was undertaken to determine the effect of administration of exogenous progesterone early in gestation on uterine levels of IGF-I mRNA and on embryo survival at day 25 of gestation in the pig. Forty-one prepubertal gilts were induced into oestrus with PG600 and artificially inseminated at their subsequent naturally occurring oestrus. Gilts were then randomly assigned to one of three groups. Gilts in the two treatment groups were injected intramuscularly with 50 mg of progesterone either from day 2 to 14 (N=14) or from day 4 to 14 (N=15) after breeding while those in the control group (N=12) were given corn oil (0.5 ml) from day 2 to 14. Between days 25 and 28 of gestation, gilts were slaughtered and reproductive tracts were recovered. Endometrial tissue (1 g) was collected and analysed for IGF-I mRNA levels using a reverse transcription-polymerase chain reaction, Progesterone treatment, starting either on day 2 or 4 after breeding, neither significantly increased embryo survival rate by day 25 of gestation nor altered IGF-I mRNA levels in uterine tissue. However, across all samples, the IGF-I mRNA level in the uterus was highly correlated with embryo survival rate (r=0.8193, p<0.01), supporting the involvement of IGF-I in the regulation of porcine embryo development.