Chronic Pulsatile Shear Stress Alters Insulin-Like Growth Factor-I (IGF-I) Binding Protein Release In Vitro

2003 ◽  
Vol 31 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Selim Elhadj ◽  
R. Michael Akers ◽  
Kimberly Forsten-Williams
Keyword(s):  
Shear Stress ◽  
Growth Factor ◽  
Binding Protein ◽  
Protein Release ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Pulsatile Shear Stress ◽  
Growth Factor I

Colocalization of insulin-like growth factor-binding protein with insulin-like growth factor I

1991 ◽  
Vol 261 (1) ◽  
pp. F22-F28 ◽  
Author(s):  
S. Kobayashi ◽  
D. R. Clemmons ◽  
M. A. Venkatachalam
Keyword(s):  
Growth Factor ◽  
Cultured Cells ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Intense Staining ◽  
Factor Binding ◽  
Factor I ◽  
Collecting Ducts ◽  
Igf I ◽  
Growth Factor I

We report the localization of insulin-like growth factor I (IGF-I) and a 25-kDa form of insulin-like growth factor-binding protein (IGF-BP-1) in adult rat kidney. The antigens were localized using a rabbit anti-human IGF-I antibody, and a rabbit anti-human IGF-BP-1 antibody raised against human 25-kDa IGF-BP-1 purified from amniotic fluid. Immunohistochemistry by the avidin-biotin peroxidase conjugate technique showed that both peptides are located in the same nephron segments, in the same cell types. The most intense staining was in papillary collecting ducts. There was moderate staining also in cortical collecting ducts and medullary thick ascending limbs of Henle's loop. In collecting ducts the antigens were shown to be present in principal cells but not in intercalated cells. In distal convoluted tubules, cortical thick ascending limbs, and in structures presumptively identified as thin limbs of Henle's loops there was only modest staining. The macula densa, however, lacked immunoreactivity. Colocalization of IGF-I and IGF-BP-1 in the same cells supports the notion, derived from studies on cultured cells, that the actions of IGF-I may be modified by IGF-BPs that are present in the same location.

Effects of insulin-like growth factor-I on aromatase cytochrome P450 activity and oestradiol biosynthesis in preimplantation porcine conceptuses in vitro

1991 ◽  
Vol 130 (2) ◽  
pp. 245-250 ◽  
Author(s):  
A. Hofig ◽  
F. A. Simmen ◽  
F. W. Bazer ◽  
R. C. M. Simmen
Keyword(s):  
Growth Factor ◽  
Aromatase Activity ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Cytochrome P450 Activity ◽  
Igf I ◽  
Growth Factor I ◽  
Oestradiol Production ◽  
P450 Activity

ABSTRACT The effects of insulin-like growth factor-I (IGF-I) on aromatase P450 activity and steroid production in preimplantation pig conceptuses were evaluated in vitro. Conceptuses recovered from gilts on days 10 and 12 of pregnancy were incubated for 6 h in modified Eagle's Minimum Essential Medium (MEM) plus IGF-I (0·1 μg/ml) or insulin (8·5 μg/ml), and conceptuses were monitored for their ability to convert [1,2-3H]β-testosterone into oestrogens. Aromatase activity of day-10 conceptuses was low and unaffected by IGF-I or insulin. In contrast, basal aromatase activity in day-12 conceptuses was about threefold higher and was further increased by IGF-I (P < 0·02), but was unaffected by insulin. To determine whether higher aromatase P450 activity was associated with increased oestradiol production, concentrations of oestradiol were determined by radioimmunoassay in culture medium of day-11 and -12 conceptuses, after incubation in MEM alone or in the presence of dehydroepiandrosterone (DHA, 1 μg/ml) with or without IGF-I (0·1 μg/ml) or insulin (0·1 or 8·5 μg/ml) for 24 h. Conceptuses in MEM plus DHA produced more oestradiol (P < 0·01) than those in MEM alone. Addition of IGF-I or insulin did not increase the effect of DHA. Basal oestradiol production was dependent on conceptus size; however, IGF-I or insulin did not affect basal or DHA-stimulated oestradiol production regardless of conceptus size. These findings demonstrate that IGF-I can modulate aromatase activity in vitro, without affecting overall de-novo steroidogenesis. Thus, the developmental increase in conceptus oestradiol production observed during early pregnancy in the pig may reflect synergistic interactions between IGF-I and other regulatory factors present within the conceptus and/or uterine environment. Journal of Endocrinology (1991) 130, 245–250

scholarly journals Insulin, Insulin-Like Growth Factor I (IGF-I), IGF-Binding Protein-1, Growth Hormone, and Feeding in the Newborn

1998 ◽  
Vol 83 (10) ◽  
pp. 3550-3557 ◽  
Author(s):  
A. L. Ogilvy-Stuart ◽  
S. J. Hands ◽  
C. J. Adcock ◽  
J. M. P. Holly ◽  
D. R. Matthews ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Igf Binding ◽  
Growth Factor I ◽  
Igf Binding Protein

SERUM INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND IGF BINDING PROTEIN (BP)-1, -3 ADAPTATIONS TO TRAINING

1998 ◽  
Vol 30 (Supplement) ◽  
pp. 173
Author(s):  
R. C. Hickson ◽  
L. P. Koziris ◽  
R. T. Chatterton ◽  
R. T. Groseth ◽  
J. M. Christie ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Serum Insulin ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Igf Binding ◽  
Growth Factor I ◽  
Igf Binding Protein
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