Insulin and insulin-like growth factor I (IGF I) in early mouse embryogenesis

Development ◽  
1990 ◽  
Vol 108 (3) ◽  
pp. 491-495
Author(s):  
R. Spaventi ◽  
M. Antica ◽  
K. Pavelic
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Indirect Evidence ◽  
Mouse Embryos ◽  
Insulin Like Growth Factor ◽  
Embryonic Cells ◽  
Mouse Development ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Growth factors have an important role in the regulation of cell growth, division and differentiation. They are also involved in the regulation of embryonic growth and differentiation. Insulin and insulin-like growth factor I (IGF I) play an important part in these events in the later stages of embryogenesis, when organogenesis is completed. In this study, we are presenting evidence that insulin and IGF I are also secreted by embryonic tissues during the prepancreatic stage of mouse development. We found measurable amounts of insulin and IGF I in 8- to 12-day-old mouse embryos. We also showed that embryonic cells derived from 8-, 9- and 10-day-old mouse embryos secrete insulin, IGF I and/or related molecules. Furthermore, the same growth factors, when added to the culture of 9-day-old mouse embryonic cells, stimulate their proliferation. These results lead to the conclusion that insulin can stimulate the growth of embryonic cells during the period when pancreas is not yet formed, which is indirect evidence for a paracrine (or autocrine) type of action.

Effects of dietary recombinant human insulin-like growth factor-I on concentrations of hormones and growth factors in the blood of newborn calves

1994 ◽  
Vol 140 (1) ◽  
pp. 15-21 ◽  
Author(s):  
C R Baumrucker ◽  
J W Blum
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Milk Replacer ◽  
Insulin Like Growth Factor ◽  
Recombinant Human Insulin ◽  
Blood Concentrations ◽  
Factor I ◽  
First Feeding ◽  
Igf I ◽  
Growth Factor I

Abstract Colostrum is rich in insulin-like growth factor-I (IGF-I) and IGF-II and the dietary effects of recombinant human IGF-I (rhIGF-I) on the newborn are of interest. The objective of this study was to examine the effects of dietary rhIGF-I upon selected hormones and growth factors in the blood. Calves were fed for the first 2 days of life with one of three experimental diets: (1) milk replacer plus isolated colostrum-derived globulin (MR−), (2) as (1) plus 98 μmol rhIGF-I/l (MR+) or (3) pooled cow colostrum. Thereafter, all animals received only milk replacer at 5% of body weight/feeding twice a day with only treatment 2 having the continued addition of 98 μmol rhIGF-I/l until completion of the experiment 7 days after birth. Radioimmunoassays for insulin, prolactin, IGF-I, IGF-II, GH, l-thyroxine, 3,5,3′-l-triiodothyroline and cortisol were conducted. With the exception of GH, all hormones and growth factors examined showed some form of dietary effect, but many were transient, changing only with the first feeding. Both insulin and prolactin concentrations exhibited a transient increase in blood at the first feeding, but insulin increased with the MR− treatment whereas prolactin increased with the MR+ treatment. Total IGF-I concentration in blood did not show any diet-induced changes for the first 4 days, but thereafter a rise in blood concentrations of IGF-I was observed. These data indirectly support the hypothesis that dietary IGF-I may be absorbed and causes transient systemic effects in the newborn calf. Journal of Endocrinology (1994) 140, 15–21

Insulin-like growth factor-I stimulates oxytocin and progesterone production by bovine granulosa cells in culture

1988 ◽  
Vol 116 (1) ◽  
pp. 97-100 ◽  
Author(s):  
D. Schams ◽  
R. Koll ◽  
C. H. Li
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Corpora Lutea ◽  
Dependent Manner ◽  
Insulin Like Growth Factor ◽  
Luteal Cells ◽  
Factor I ◽  
Igf I ◽  
Epidermal Growth ◽  
Growth Factor I

ABSTRACT The effect of insulin-like growth factor-I (IGF-I), epidermal growth factor (EGF), fibroblast growth factor (FGF) and nerve growth factor (NGF) on production of oxytocin and progesterone by cultured bovine granulosa and luteal cells was studied. Secretion of oxytocin was stimulated, in a dose-dependent manner, by IGF-I at 48 and 120 h of culture to levels much higher than those after stimulation with LH, FSH, EGF, FGF or NGF. A similar effect of IGF-I was observed for progesterone but, in contrast to oxytocin, secretion of progesterone was not increased by EGF, NGF or FGF. During primary culture, for 4 h, of dispersed bovine luteal cells obtained from corpora lutea between days 4 and 10 of the oestrous cycle, all the growth factors tested failed to stimulate secretion of oxytocin or progesterone. The data suggest the relevance of growth factors (especially IGF-I) for ovarian physiology and their possible importance for differentiation of follicles and luteinization. J. Endocr. (1988) 116, 97–100

Anabolic influences of insulin-like growth factor I and/or growth hormone on the diaphragm of young rats

1997 ◽  
Vol 82 (6) ◽  
pp. 1972-1978 ◽  
Author(s):  
Michael I. Lewis ◽  
Thomas J. Lorusso ◽  
Mario Fournier
Keyword(s):  
Growth Hormone ◽  
Growth Factors ◽  
Growth Factor ◽  
Body Growth ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Young Rats ◽  
Igf I ◽  
Adolescent Rats ◽  
Growth Factor I

Lewis, Michael I., Thomas J. LoRusso, and Mario Fournier.Anabolic influences of insulin-like growth factor I and/or growth hormone on the diaphragm of young rats. J. Appl. Physiol. 82(6): 1972–1978, 1997.—It is controversial whether insulin-like growth factor I (IGF-I), growth hormone (GH), or their combination might enhance body growth and/or tissue anabolism in the well-fed animal with an intact somatotrophic axis. To assess this further, we studied four groups of adolescent rats: 1) control (Ctr), 2) GH, 3) IGF-I, and 4) GH/IGF-I. IGF-I was given via an osmotic minipump, whereas GH was injected subcutaneously for a period of 72 h. Diaphragm (Dia) contractile and fatigue properties were determined in vitro. Quantitative histochemical and morphometric analyses were performed on Dia fibers. Total serum IGF-I levels were significantly increased in the groups receiving growth factors. Although body weight increased to a greater extent in the animals receiving growth factors, a further synergistic effect was noted in the GH/IGF-I animals compared with either GH or IGF-I groups. Costal Dia mass was greater in the groups receiving growth factors. The Dia of GH/IGF-I animals was more fatigue resistant than the Dia in Ctr. The cross-sectional area of types IIa and IIx fibers were increased to a similar extent in all groups receiving growth factors compared with Ctr. Succinate dehydrogenase activity of type IIa fibers was significantly greater in the GH/IGF-I animals compared with the other groups. We conclude that the short-term provision of growth factors to well-nourished, normally growing adolescent rats can accelerate body growth and promote selective hypertrophy of predominantly type II Dia fibers.

Characterization of insulin-like growth factor I and epidermal growth factor receptors in meningioma

1989 ◽  
Vol 71 (4) ◽  
pp. 538-544 ◽  
Author(s):  
Masaki Kurihara ◽  
Yoshiharu Tokunaga ◽  
Keisuke Tsutsumi ◽  
Tsutomu Kawaguchi ◽  
Kazuto Shigematsu ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Number Of Binding Sites ◽  
Epidermal Growth ◽  
Growth Factor I

✓ Receptors for insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) were localized and characterized in eight samples of human meningioma (four fibrous, two meningothelial, and two angioblastic types), using quantitative autoradiographic techniques. Effects of both growth factors on deoxyribonucleic acid (DNA) synthesis in the cultured meningioma cells were examined. High numbers of specific binding sites for both IGF-I and EGF were homogeneously present in tissue sections derived from fibrous and meningothelial types of meningiomas, whereas binding sites for these growth factors were not detectable in adjacent leptomeninges. While relatively large numbers of IGF-I binding sites were located in the wall of the intratumoral vasculature, the number of binding sites in the stromal component was lower in angioblastic-type meningiomas, including a low number of EGF binding sites detected only in the stromal portion. Scatchard analysis revealed the presence of a single class of high-affinity binding sites for both IGF-I and EGF in the meningiomas examined (dissociation constant (Kd) = 0.6 to 2.9 nM, and the maximum number of binding sites (Bmax) = 16 to 80 fmol/mg for IGF-I; and Kd = 0.6 to 4.0 nM, Bmax = 3 to 39 fmol/mg for EGF). Both growth factors increased the synthesis of DNA, in a dose-dependent manner, as measured by 3H-thymidine incorporation. The combination of IGF-I and EGF synergistically stimulated the synthesis of DNA, and the effects seen with 10% fetal bovine serum could be reproduced at a concentration of 10−10 M. These observations can be interpreted to mean that both IGF-I and EGF may be involved in the growth modulation of meningiomas, possibly through paracrine or autocrine mechanisms.

Autocrine control of wound repair by insulin-like growth factor I in cultured endothelial cells

1993 ◽  
Vol 265 (3) ◽  
pp. C801-C805 ◽  
Author(s):  
W. R. Taylor ◽  
R. W. Alexander
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Wound Repair ◽  
Repair Process ◽  
Insulin Like Growth Factor ◽  
Wound Edge ◽  
Factor I ◽  
Autocrine Control ◽  
Igf I ◽  
Growth Factor I

The repair process of the vascular endothelium is modulated by growth factors from both endogenous (within the vessel wall) and exogenous (blood borne) sources. We utilized a tissue culture model of endothelial wounding to gain further insight into the potential autocrine control of proliferation during wound repair. Cultured porcine aortic endothelial monolayers were mechanically wounded by passing a 7-mm sterile glass rod over the surface of the culture. Proliferation at the wound edge was quantified using [3H]thymidine autoradiography. In wounded cultures incubated in media supplemented with 10% fetal calf serum, 81 +/- 2% of the nuclei at the wound edge were labeled. When the cultures were incubated in serum-free media, proliferation at the wound edge was only slightly diminished with 65 +/- 3% (P < 0.05) of the cells labeled. These findings raise the possibility that there is a significant contribution from autocrine growth factors to endothelial wound repair. To evaluate the potential role of insulin-like growth factor I (IGF-I) in the wound repair process, we used a radioimmunoassay to measure IGF-I secretion. Wounded cultures exhibited a 187 +/- 58% increase in IGF-I production when compared with nonwounded cultures (P < 0.05). To determine the extent to which endogenous IGF-I mediates the proliferative response of endothelial cell monolayers to wounding, wounded cultures were incubated with inactivating concentrations of IGF-I antibody. When IGF-I antibody was present in the culture media, only 26 +/- 3% of the nuclei at the wound edge were labeled with [3H]thymidine (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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