IGF-I and IGF-binding protein-3 in plasma of GH-deficient rats

1996 ◽  
Vol 150 (1) ◽  
pp. 67-76 ◽  
Author(s):  
A A Butler ◽  
B W Gallaher ◽  
G R Ambler ◽  
P D Gluckman ◽  
B H Breier
Keyword(s):  
Mrna Expression ◽  
Ternary Complex ◽  
Insulin Treatment ◽  
Binding Protein ◽  
Saline Control ◽  
Treatment Groups ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

Abstract The majority of IGF-I circulates in a large (150 kDa) ternary complex with IGF-binding protein-3 (IGFBP-3) and a non-IGF-binding acid-labile subunit. The secretion of ternary complex into the circulation from liver has been considered to be GH-dependent; however, recent data indicate that GH does not directly regulate hepatic IGFBP-3 synthesis. To examine the role of insulin in regulating plasma IGFBP-3 levels, postpubertal male GH-deficient (dw/dw) rats were treated every 8 h with injections (s.c.) of 0·9% saline, 20 μg insulin/day, 200 μg hIGF-I/day, or 20 μg insulin/day plus 200 μg hIGF-I/day, for 10 days with the animals being killed 2–3 h after the final injection. Hypoglycaemia was not observed in any of the treatment groups. hIGF-I treatment increased longitudinal growth and weight gain (P<0·05), while insulin treatment had no effect. Plasma IGF-I levels were increased in groups treated with hIGF-I (P<0·05), while insulin treatment resulted in a reduction (P<0-05): saline=267·1 ± 15·6 (ng/ml ± s.e.m.), insulin=219·3 ± 17·5, hIGF-I=391·7 ± 17·6, insulin plus hIGF-I=357·5 ± 31·8. Hepatic IGF-I mRNA expression was increased in insulin-treated dw/dw rats in comparison with hIGF-I-treated animals (P<0·05) but not in comparison with saline control or the combined treatment groups. Plasma levels of intact IGFBP-3, measured by ligand blot analysis, were increased in all treatment groups compared with saline (P<0·05): saline=100·0 ± 9·4% (% of saline ± s.e.m.), insulin=149·9 ± 17·5%, hIGF-I= 191·4 ± 17·3%, insulin plus hIGF-I=205·4 ± 15·3%. The levels of the 28/32 kDa IGFBPs and IGFBP-4 in plasma were increased by hIGF-I treatment (P<0·05) but not by insulin treatment. Hepatic specific 125I-bovine GH binding was not significantly different in any of the treatment groups. This study provides the first evidence in non-diabetic animals that insulin regulates hepatic IGF-I mRNA expression, plasma IGF-I and plasma IGFBP-3 levels in the GH-deficient state without changes in hepatic GH receptors. The divergent response of plasma IGF-I and IGFBP-3 levels to insulin treatment in the present study may indicate an effect of insulin on the clearance of IGF-I from the circulation. Journal of Endocrinology (1996) 150, 67–76

Specimen processing time and measurement of total insulin-like growth factor-I (IGF-I), free IGF-I, and IGF binding protein-3 (IGFBP-3)

2006 ◽  
Vol 16 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Tiffany G. Harris ◽  
Howard D. Strickler ◽  
Herbert Yu ◽  
Michael N. Pollak ◽  
E. Scott Monrad ◽  
...  
Keyword(s):  
Growth Factor ◽  
Processing Time ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Specimen Processing ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

scholarly journals Genetic Determinants of Circulating Insulin-Like Growth Factor (IGF)-I, IGF Binding Protein (BP)-1, and IGFBP-3 Levels in a Multiethnic Population

2007 ◽  
Vol 92 (9) ◽  
pp. 3660-3666 ◽  
Author(s):  
Iona Cheng ◽  
Katherine DeLellis Henderson ◽  
Christopher A. Haiman ◽  
Laurence N. Kolonel ◽  
Brian E. Henderson ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Genetic Determinants ◽  
Igf I ◽  
Igf Binding ◽  
Multiethnic Population ◽  
Igf Binding Protein ◽  
Igfbp 3

Moderate food restriction reduces serum IGF-I and alters circulating IGF-binding protein profiles in lactating rats

1997 ◽  
Vol 152 (2) ◽  
pp. 303-316 ◽  
Author(s):  
M H Monaco ◽  
S M Donovan
Keyword(s):  
Body Weight ◽  
Mammary Gland ◽  
Food Restriction ◽  
Binding Protein ◽  
Igf I ◽  
Pregnancy And Lactation ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Serum Gh ◽  
Igfbp 3

Abstract The role of somatogenic and lactogenic hormones in the adaptative mechanisms which occur in response to nutrient restriction during lactation is unknown. To characterize the effect of food restriction during lactation on serum IGF-I, GH and prolactin concentrations and serum IGF-binding protein (IGFBP) profiles, lactating dams had free access to food (control) or were restricted to 60% of control intake during pregnancy and lactation (RPL) or only during lactation (RL). Serum, milk and mammary gland samples were collected throughout lactation. RL dams lost body weight, control dams gained weight, while RPL dams maintained body weight during lactation. By day 20, body and mammary gland weights of RL and RPL dams did not differ and were lower than control (P<0·05). Serum IGF-I concentrations in restricted groups were lower than control (P<0·05), however, hepatic expression of IGF-I mRNA did not differ between groups in early (day 1) or mid-lactation (day 8) and was increased on day 20 in RL dams compared with RPL or control. These data suggest that serum IGF-I and hepatic IGF-I mRNA expression are not co-ordinately regulated in the food-restricted lactating rat. In early lactation, serum IGFBP-3 was lower in RPL dams than control (P<0·05), whereas IGFBP-1 and -2 were increased in RL and RPL dams in late lactation compared with control. The decrease in IGFBP-3 and increase in lower molecular weight IGFBP may have contributed to the reduction in serum IGF-I by increasing IGF-I clearance from the circulation. Serum GH and prolactin were measured in samples obtained between 0900 and 1200 h. Serum GH did not differ with the exception of an increase on day 1 in control relative to RPL dams and on day 20 in RL dams relative to RPL and control. Serum prolactin was higher in the RL dams than controls on day 4. In summary, food restriction during pregnancy and lactation or solely during lactation results in similar reductions in serum IGF-I and alterations in serum IGFBP despite differences in body weight responses to food restriction during lactation. Journal of Endocrinology (1997) 152, 303–316

scholarly journals IGF-I, IGF Binding Protein (IGFBP)-3, Phosphoisoforms of IGFBP-1, and Postnatal Growth in Very Low Birth Weight Infants

2002 ◽  
Vol 87 (5) ◽  
pp. 2171-2179 ◽  
Author(s):  
Eero Kajantie ◽  
Leo Dunkel ◽  
Eeva-Marja Rutanen ◽  
Markku Seppälä ◽  
Riitta Koistinen ◽  
...  
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Very Low Birth Weight ◽  
Binding Protein ◽  
Postnatal Growth ◽  
Low Birth Weight Infants ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

scholarly journals The transfection-induced overexpression of IGF-binding protein-4 affects the secretory activity of porcine ovarian granulosa cells and their response to hormones and IGF-I

2001 ◽  
Vol 26 (3) ◽  
pp. 241-248 ◽  
Author(s):  
AV Sirotkin ◽  
AV Makarevich ◽  
MR Corkins ◽  
J Kotwica ◽  
J Bulla
Keyword(s):  
Growth Factor ◽  
Granulosa Cells ◽  
Binding Protein ◽  
Secretory Activity ◽  
Ovarian Granulosa Cells ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Cells Cultured ◽  
Igfbp 3

The aim of our studies was to examine whether IGF-binding protein (IGFBP)-4 is involved in the control of the secretion of various ovarian substances and also the mediation of the effects of several hormones and growth factors on this secretion. For this purpose, we carried out the transfection of porcine granulosa cells with a cDNA sense construct, increasing IGFBP-4 synthesis. We then compared the release of IGFBP-3, progesterone, oxytocin and IGF-I by control and transfected cells cultured with and without porcine LH (100 ng/ml), porcine GH (100 ng/ml), IGF-I (10 ng/ml), oxytocin (10 ng/ml) and estradiol-17beta (100 ng/ml). The concentration of IGFBP-4 produced was assessed using ligand blotting, and the release of progesterone, oxytocin, IGF-I and IGFBP-3 was evaluated using RIA/IRMA techniques. It was observed that GH, IGF-I, estradiol, LH and oxytocin alter the progesterone, oxytocin, IGF-I and IGFBP-3 release by porcine ovarian granulosa cells. Transfection of these cells with an IBFBP-4 cDNA expression construct significantly increased the IGFBP-4 accumulation in cell-conditioned medium. Furthermore, this transfection significantly reduced progesterone, oxytocin and IGFBP-3 release, and increased IGF-I output in cells cultured in the absence or presence of GH, IGF-I, estradiol and LH. The addition of oxytocin, but not of other tested substances, fully or partially prevented the effects of IGFBP-4 overexpression on IGFBP-3, IGF-I, but not on progesterone release. The present results suggested that IGFBP-4, as well as GH, IGF-I, estradiol, LH and oxytocin, is a potent regulator of porcine ovarian steroid (progesterone), nonapeptide hormone (oxytocin), growth factor (IGF-I) and growth factor-binding protein (IGFBP-3) release. IGFBP-4 is an inhibitor of basal progesterone, oxytocin and IGFBP-3 release and a stimulator of IGF-I output by porcine ovarian cells. The action of IGFBP-4 on the ovary can be mediated by (1) inhibition of oxytocin release, (2) suppression of receptor/postreceptor events induced by other hormones and IGF-I and (3) stimulation of IGF-I release.

Changes induced by non-enzymatic glycosylation of IGF-binding protein-3: effects on its binding properties and on its modulatory effect on IGF-I mitogenic action

1995 ◽  
Vol 144 (1) ◽  
pp. 119-126 ◽  
Author(s):  
A M Cortizo ◽  
J J Gagliardino
Keyword(s):  
Binding Protein ◽  
Mitogenic Activity ◽  
Dependent Manner ◽  
Binding Properties ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Enzymatic Glycosylation ◽  
Igfbp 3

Abstract The aim of this study was to demonstrate the feasibility of in vitro non-enzymatic glycosylation of IGF-binding protein-3 (IGFBP-3) and whether this process affects its binding properties and its modulatory effect on IGF-I mitogenic activity. Swiss 3T3 fibroblasts were cultured and the IGFBP-3 released into the medium (CM) glycated with either labelled or unlabelled glucose. Parallel glycation studies were performed using standard human IGFBP-3. Both species of IGFBP-3 became effectively glycated in a dose-dependent manner. Glycated IGFBP-3 bound larger amounts of 125I-labelled IGF-I than its non-glycated form. According to Scatchard analysis this effect might be due to an increase in the number of binding sites of the IGFBP-3 molecule rather than to changes in its affinity constants, which remain unchanged. Preincubation of fibroblasts with CM containing IGFBP-3 for 16 h before the addition of IGF-I enhanced the stimulatory effect of the hormone on thymidine incorporation into cell DNA. This potentiation was blunted when in vitro glycated instead of non-glycated IGFBP-3 was employed. These results provide further evidence of the in vitro glycation of IGFBP-3 and demonstrate that this process affects both its binding properties and its enhancing effect on IGF-I mitogenic activity. These changes may explain, at least partially, the development of many alterations observed in poorly controlled diabetic patients. Journal of Endocrinology (1995) 144, 119–126

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