scholarly journals Interstitial IGF-I in exercising skeletal muscle in women

2007 ◽  
Vol 157 (4) ◽  
pp. 427-435 ◽  
Author(s):  
U Berg ◽  
T Gustafsson ◽  
C J Sundberg ◽  
L Kaijser ◽  
C Carlsson-Skwirut ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Molecular Forms ◽  
Igf I ◽  
Igf Binding ◽  
Muscle Compartment ◽  
Level Of Significance ◽  
Igf Binding Protein ◽  
Design And Methods ◽  
Local Release ◽  
Igfbp 3

Objective: To study interstitial IGF-I concentrations in resting and exercising skeletal muscle in relation to the circulating components of the IGF–IGF binding protein (IGFBP) system. Design and methods: Seven women performed endurance exercise with 1 leg (Ex-leg) for 1 h. The resting leg (Rest-leg) served as a control. IGF-I was determined in microdialysate (MD) and was compared with veno-arterial (v-a) concentrations of circulating IGF–IGFBP components. Results: Median (range) basal MD-IGF-I was 0.87 (0.4–1.5) μg/l or 0.4 (0.2)% of total-IGF-I (t-IGF-I) determined in arterial serum and in the same concentration range as free dissociable IGF-I (f-IGF-I). Rest-leg MD-IGF-I decreased, reaching significance after exercise. Ex-leg MD-IGF-I was unchanged during exercise and declined after exercise at the level of significance (P = 0.05). There was a release of f-IGF-I from the Ex-leg into the circulation at the end of and shortly after exercise. A small but significant increase in circulating IGFBP-1 was detected at the end of exercise and IGFBP-1 increased further after exercise. Although interleukin-6 (IL-6) has been associated with IGFBP-3 proteolysis, the circulating molecular forms of IGFBP-3 remained unchanged in spite of an IL-6 release from the muscle compartment. Conclusions: Circulating IGFBP-1 is related to interstitial IGF-I in resting muscle although the temporal relationship may not be simple. Further studies should explore the role of local release of IGF-I and its impact on IGF-I activity during contraction.

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 Dexamethasone administration attenuates the inhibitory effect of lipopolysaccharide on IGF-I and IGF-binding protein-3 in adult rats

2005 ◽  
Vol 185 (3) ◽  
pp. 467-476 ◽  
Author(s):  
Teresa Priego ◽  
Miriam Granado ◽  
Ana Isabel Martín ◽  
Asunción López-Calderón ◽  
María Angeles Villanúa
Keyword(s):  
Gene Expression ◽  
Inhibitory Effect ◽  
Mrna Levels ◽  
Serum Concentrations ◽  
Gh Receptor ◽  
Its Gene ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

The aim of this study was to investigate whether glucocorticoid administration had a beneficial effect on serum concentrations of insulin-like growth factor I (IGF-I) and on IGF-binding protein 3 (IGFBP-3) in rats injected with lipopolysaccharide (LPS). Adult male rats were injected with LPS or saline and pretreated with dexamethasone or saline. Dexamethasone administration decreased growth hormone (GH) receptor and IGF-I mRNA levels in the liver of control rats. LPS decreased GH receptor and IGF-I gene expression in the liver of saline-treated rats but not in the liver of dexamethasone-pretreated rats. In the kidney, GH receptor mRNA levels were not modified by dexamethasone or LPS treatment. However, LPS decreased renal IGF-I gene expression and dexamethasone pretreatment prevented this decrease. Serum concentrations of IGF-I were decreased by LPS, and dexamethasone pretreatment attenuated this effect. The gene expression of IGFBP-3 in the liver and kidney and its circulating levels were decreased by LPS. In control rats dexamethasone increased circulating IGFBP-3 and its gene expression in the liver, and decreased the proteolysis of this protein. Dexamethasone pretreatment attenuated the LPS-induced decrease in IGFBP-3 gene expression in the liver and prevented the LPS-induced decrease in IGFBP-3 gene expression in the kidney. Moreover, dexamethasone pretreatment attenuated the LPS-induced decrease in serum concentrations of IGFBP-3 and decreased the LPS-induced IGFBP-3 proteolysis in serum. In conclusion, dexamethasone pretreatment partially attenuates the inhibitory effect of LPS on serum IGF-I by blocking the decrease of its gene expression in the kidney as well as by attenuating the decrease in serum concentrations of 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

Sign in / Sign up

Export Citation Format

Share Document