scholarly journals Insulin-like growth factor 1 can decrease degradation and promote synthesis of proteoglycan in cartilage exposed to cytokines

1989 ◽  
Vol 260 (2) ◽  
pp. 543-548 ◽  
Author(s):  
J A Tyler
Keyword(s):  
Growth Factor ◽  
Interleukin 1 ◽  
Molecular Size ◽  
Qualitative Change ◽  
Relative Increase ◽  
Proteoglycan Synthesis ◽  
Insulin Like Growth Factor ◽  
Dose Dependent ◽  
Fold Stimulation

A model system of explanted cartilage has been used in vitro to determine whether insulin-like growth factor 1 (IGF 1), which promotes matrix formation is effective in the presence of cytokines such as interleukin 1 (IL1) and tumour necrosis factor (TNF), which induce net matrix depletion. IGF 1 induced a dose-dependent 2.5-fold stimulation of proteoglycan synthesis, with a half-maximal dose of 25 ng/ml. A similar relative increase occurred in response to IGF 1 (10-100 ng/ml) in cartilage cultured also with IL1 or TNF (5-500 pM). There was no detectable qualitative change in the average molecular size or charge of the aggregating proteoglycan synthesized by explants exposed to IGF 1 alone or with IL1 or TNF. The increased production of prostaglandin E2, which is initiated when IL1 or TNF bind to the chondrocytes, was the same in the presence or absence of IGF 1. The time taken for 50% of pre-labelled proteoglycan to be released from the explants (t1/2) increased in the presence of IGF 1 (100 ng/ml) from 21 to 32 days in control cultures and from 8 to 26 days in cartilage cultured with IL1 (50 pM). It is concluded that IGF 1 enhances the synthesis of aggregating proteoglycan in cartilage exposed to cytokines and can directly decrease both the basal and the cytokine-stimulated degradation of proteoglycan in cartilage.

The effect of insulin-like growth factor (IGF) and of human serum on steps in proteoglycan synthesis

1981 ◽  
Vol 97 (4) ◽  
pp. 503-507 ◽  
Author(s):  
Avivah Silbergeld ◽  
Rivka Mamet ◽  
Zvi Laron ◽  
Zvi Nevo
Keyword(s):  
Growth Factor ◽  
Human Serum ◽  
Chondroitin Sulphate ◽  
Proteoglycan Synthesis ◽  
Dependent Manner ◽  
Insulin Like Growth Factor ◽  
Intact Cartilage ◽  
Normal Human ◽  
Sugar Chains ◽  
Dose Dependent

Abstract. Embryonic chick pelvic cartilages were incubated in the presence of insulin like growth factor (IGF) (1–100 μU/ml), as well as normal human serum (5%), with radiolabelled precursors of proteoglycan (PG) synthesis: L-[3-3H]serine, D-[6-3H]glucosamine and [35S]Na2SO4. IGF alone (1–15 μU/ml), stimulated in a dose-dependent manner D-[6-3H]glucosamine incorporation into tissue-bound and soluble isolated glycosaminoglycan (GAG) chains. L-[3-3H]serine incorporation into PG molecules was not stimulated by IGF (1–100 μU/ml), despite the increase in the uptake of this precursor into intact cartilage. [35S]Na2SO4 incorporation was unaffected by IGF. Serum promoted the uptake of all three precursors into tissue-bound glycosaminoglycans. It was postulated that IGF could stimulate proteoglycan synthesis not only by elongating existing chondroitin sulphate chains but also by increased synthesis of other sugar chains e.g. keratan sulphate and oligosaccharides.

scholarly journals In Vitro Changes in Secretion Activity of Rat Ovarian Fragments Induced by Molybdenum

2014 ◽  
pp. 807-809 ◽  
Author(s):  
S. ROYCHOUDHURY ◽  
L. DETVANOVA ◽  
A. V. SIROTKIN ◽  
R. TOMAN ◽  
A. KOLESAROVA
Keyword(s):  
Growth Factor ◽  
Ammonium Molybdate ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Study Results ◽  
Igf I ◽  
17Β Estradiol ◽  
Growth Factor I ◽  
Dose Dependent

The aim of this in vitro study was to examine the secretion activity (progesterone, 17β-estradiol and insulin-like growth factor-I) of rat ovarian fragments after molybdenum (Mo) addition. Rat ovarian fragments were incubated with ammonium molybdate (NH4)6Mo7O24.4H2O at the doses 90, 170, 330 and 500 µg.ml-1 for 24 h and compared with control group without Mo addition. Release of progesterone (P4), estradiol (17β-estradiol) and insulin-like growth factor I (IGF-I) by ovarian fragments was assessed by radioimmunoassay (RIA). Data show that P4 release by ovarian fragments was not affected by (NH4)6.Mo7O24.4H2O addition at all the doses used (90-500 µg.ml-1). However, addition of ammonium molybdate was found to cause a significant (P<0.05) dose-dependent decrease (at the doses 90, 170 and 500 µg.ml-1) in release of 17β-estradiol by ovarian fragments in comparison to control. Also, addition of ammonium molybdate significantly (P<0.05) inhibited IGF-I release at all the doses (90-500 µg.ml-1) used in the study. Results suggest ammonium molybdate induced inhibition in the release of growth factor IGF-I and its dose-dependent effect on secretion of steroid hormone 17β-estradiol but not progesterone. These data contribute to new insights regarding the mechanism of action of Mo on rat ovarian functions.

Effects of recombinant bovine somatotrophin, insulin-like growth factor-I and insulin on the proliferation of bovine granulosa cells in vitro

1993 ◽  
Vol 139 (1) ◽  
pp. 67-75 ◽  
Author(s):  
J. G. Gong ◽  
D. McBride ◽  
T. A. Bramley ◽  
R. Webb
Keyword(s):  
Growth Factor ◽  
Granulosa Cells ◽  
Ovarian Follicles ◽  
Dependent Manner ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Dose Dependent ◽  
Bovine Somatotrophin

ABSTRACT Treatment of heifers with recombinant bovine somatotrophin (BST) significantly increases the population of small ovarian follicles and peripheral concentrations of somatotrophin, insulin-like growth factor-I (IGF-I) and insulin. To investigate the possible mechanism(s) involved in the action of BST on ovarian follicles, the effects of BST, IGF-I and insulin, given alone or in combination with either FSH or LH, on the proliferation of bovine granulosa cells in vitro were examined using a serum-free culture system. Bovine granulosa cells were obtained from antral follicles classified into three size categories according to diameter: small <5 mm; medium-sized 5–10 mm and large >10 mm. The proliferation of granulosa cells was assessed by the incorporation of [3H]thymidine into the cultured cells. Both FSH and LH (1–1000 ng/ml) inhibited the proliferation of bovine granulosa cells obtained from all three size classes of follicles in a dose-dependent manner. BST, at doses ranging from 1 to 1000 ng/ml, had no effect on the proliferation of granulosa cells from small and medium-sized follicles, but inhibited the division of granulosa cells from large follicles in a dose-dependent manner. Treatment with either IGF-I (10–3000 ng/ml) or insulin (0·5–1000 ng/ml) stimulated, in a dose-dependent manner, the proliferation of granulosa cells obtained from all three size categories of follicles. No synergistic interaction between BST (30 ng/ml) and either FSH (50 ng/ml) or LH (5 ng/ml) was observed in granulosa cells from all three size classes of follicles. In contrast, physiological concentrations of both IGF-I (100 ng/ml) and insulin (1 ng/ml) acted in synergy with both FSH (50 ng/ml) and LH (5 ng/ml) to stimulate the proliferation of granulosa cells from small follicles, whilst no such synergistic interactions were observed in granulosa cells from medium-sized and large follicles. It was concluded that the increase in the number of small ovarian follicles induced by BST treatment in heifers may be mediated by increased peripheral concentrations of IGF-I and/or insulin, possibly acting in synergy with gonadotrophins. Furthermore, insulin probably acts through its own receptor rather than acting via the type-I IGF receptor, as it can stimulate the proliferation of bovine granulosa cells at physiological concentrations. Journal of Endocrinology (1993) 139, 67–75

Blended Effects of Herbal Components of Tokishakuyakusan on Somatomedin C/Insulin-like Growth Factor 1 Level in Rat Corpus Luteum

1991 ◽  
Vol 19 (01) ◽  
pp. 61-64 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Growth Factor ◽  
Corpus Luteum ◽  
Corpora Lutea ◽  
Insulin Like Growth Factor ◽  
Somatomedin C ◽  
Factor I ◽  
Peony Root ◽  
Growth Factor I ◽  
Herbal Components

The effect of herbal components of Tokishakuyakusan on somatomedin C/insulin-like growth factor I (IGF-1) level in medium from rat corpora lutea incubated in vitro was examined. Hoelen + peony root + Japanese angelica root, hoelen + peony root, hoelen + Japanese angelica root or peony root + Japanese angelica root decreased the IGF-1 level. The data suggest that constituent herbal components of Tokishakuyakusan regulate the IGF-1 level by rat corpora lutea.

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