scholarly journals The Effect of HT-2 Toxin on Ovarian Steroidogenesis and Its Response to IGF-I, Leptin and Ghrelin in Rabbits

2017 ◽  
pp. 705-708 ◽  
Author(s):  
A. KOLESAROVA ◽  
N. MARUNIAKOVA ◽  
A. KADASI ◽  
M. HALENAR ◽  
M. MARAK ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fusarium Species ◽  
Endocrine System ◽  
Control Group ◽  
Trichothecene Mycotoxin ◽  
Ovarian Steroidogenesis ◽  
Estradiol Secretion ◽  
Igf I ◽  
17Β Estradiol

T-2 toxin and its metabolite HT-2 toxin are one of the most toxic mycotoxins of type A-trichothecenes, which are produced mainly by Fusarium species. Therefore, study of Fusarium toxins T-2 toxin and HT-2 toxin is an essential issue because they could also play role in failures of reproductive functions as well as endocrine system of domestic animals. Assessment of the effect of A-trichothecene mycotoxin HT-2 toxin alone or combined with insulin-like growth factor (IGF-I), leptin and ghrelin on estradiol secretion by rabbit ovarian fragments in vitro was done. Rabbit ovarian fragments were incubated without (control group) or with HT-2 toxin, or its combinations with IGF-I, leptin and ghrelin at various concentrations for 24 h. Secretion of 17β-estradiol was determined by ELISA. Firstly, HT-2 toxin at the doses 10 and 100 ng.ml-1, but not at 1 ng.ml-1 decreased 17β-estradiol secretion by ovarian fragments. Secondly, 17β-estradiol secretion was not affected by HT-2 toxin exposure combined with growth factor IGF-I, metabolic hormones leptin and ghrelin. In conclusion, HT-2 toxin has potent direct dose-dependent effects on ovarian steroidogenesis in rabbits. These direct effects of HT-2 mycotoxin on ovarian steroidogenesis could impact negatively on the reproductive performance of rabbits.

scholarly journals Possible mechanism for acceleration of meiotic progression of bovine follicular oocytes by growth factors in vitro

Reproduction ◽  
2002 ◽  
pp. 135-142 ◽  
Author(s):  
M Sakaguchi ◽  
T Dominko ◽  
N Yamauchi ◽  
ML Leibfried-Rutledge ◽  
T Nagai ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Kinase Activity ◽  
Polar Body ◽  
Control Group ◽  
Meiotic Cell ◽  
Treatment Groups ◽  
Igf I ◽  
Polar Body Extrusion

The mechanism for the accelerating effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on the meiotic cell cycle of bovine oocytes cultured in vitro was investigated. Cumulus-oocyte complexes (COCs) were obtained from small (< or = 3 mm in diameter), medium (4-6 mm in diameter) or large (7-10 mm in diameter) ovarian follicles and cultured with or without a combination of EGF and IGF-I (growth factors). Growth factors significantly increased the frequency of first polar body extrusion of oocytes derived from small follicles at 16 h of culture (PB16 oocytes; with growth factors: 75%; without growth factors: 55%), but did not increase the frequency in oocytes from medium or large follicles. COCs from small follicles were cultured with individual growth factors and sampled for kinase activity. The frequencies of polar body extrusion in EGF only (67%) and EGF + IGF-I (75%) treatment groups were significantly higher than those in the control (no growth factor) group (49%), but not significantly higher than in the IGF-I only group (63%). The H1 kinase activity at 6-8 h of culture in each group increased significantly from the baseline value at 0 h of culture, and the H1 kinase activities in the EGF only, IGF-I only and EGF + IGF-I treatment groups were significantly higher than those in the control group at 8 h of culture. MAP kinase activity was significantly higher than the baseline value and significantly higher than that in the control group at 6 h of culture in the EGF treatment group only. In conclusion, EGF and IGF-I act on COCs from small follicles to accelerate the meiotic cell cycle of the oocytes. This accelerating effect may be related to increased H1 and MAP kinase activities during the early stages of maturation.

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.

209 A COMPARISON OF THE EFFECTS OF DEFINED, SEMI-DEFINED, AND UNDEFINED MATURATION MEDIA ON CLEAVAGE AND SUBSEQUENT EMBRYO DEVELOPMENT OF SHEEP OOCYTES

2009 ◽  
Vol 21 (1) ◽  
pp. 202
Author(s):  
H. Karami Shabankareh ◽  
M. Zandi
Keyword(s):  
Growth Factor ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Statistical Significance ◽  
In Vitro Production ◽  
Efficient System ◽  
Significant Difference ◽  
Igf I ◽  
17Β Estradiol

The objectives were to determine the effects of addition of growth factor(s) and antioxidant to defined (DMM), semi-defined (SDMM), or undefined (UDMM) sheep oocyte maturation media on cleavage and subsequent embryo development. Exogenous epidermal growth factor (EGF, 10 ng mL–1), insulin-like growth factor-I (IGF-I, 50 ng mL–1), or cysteamine (Cys, 100 m) was added to DMM, SDMM, or UDMM. In the experiments, 967 oocytes were collected from 1160 ovaries (Experiment 1), 770 oocytes were collected from 831 ovaries (Experiment 2), and 778 oocytes were collected from 845 ovaries (Experiment 3). After in vitro fertilization with fresh ram semen in SOF medium, groups of 10 oocytes were stripped free of cumulus cells and transferred into 50 μL of a 2-step SOF medium. The incubations were conducted under paraffin oil at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90% N2. In all experiments, data were analyzed by ANOVA. Duncan’s multiple range test was used to determine the difference between 2 means after ANOVA. Results were expressed as mean ± SEM, and statistical significance was accepted from P < 0.05. In Experiment 1, the effects of IGF-I and EGF in DMM (TCM-199 supplemented with FSH, LH, 17β-estradiol, Na pyruvate, gentamycin sulfate, and polyvinyl alcohol) were evaluated in 4 treatment groups (DMM as a control, DMM + EGF, DMM + IGF-I, and DMM + EGF + IGF-I). Cleavage, morula, and blastocyst production rates were higher in the DMM + EGF + IGF-I (83.1 ± 0.5, 47.7 ± 0.5, and 30.8 ± 1.2) than in the DMM (72.9 ± 1.3, 37.0 ± 1.1, and 20.2 ± 1.2), DMM + EGF (77.2 ± 1.0, 43.2 ± 2.1, and 26.1 ± 1.8), or DMM + IGF-I (79.9 ± 0.6, 43.3 ± 1.2, and 25.7 ± 1.3) groups (P < 0.05). In Experiment 2, the effects of Cys in DMM were evaluated. The addition of Cys to DMM + EGF + IGF-I resulted in a mean blastocyst rate of 35.0 ± 0.9% compared with 31.5 ± 1.3% in DMM + EGF + IGF-I alone (P < 0.05); however, mean cleavage rates (84.5 ± 1.3 v. 82.8 ± 1.0) did not differ (P = 0.32). In Experiment 3, the effects of DMM + EGF + IGF-I + Cys, SDMM (TCM-199 supplemented with FSH, LH, 17β-estradiol, Na pyruvate, gentamycin sulfate, and BSA) + EGF + IGF-I + Cys, and UDMM (TCM-199 supplemented with FSH, LH, 17β-estradiol Na pyruvate, gentamycin sulfate, and FBS) + EGF + IGF-I + Cys on cleavage and embryo developmental were compared. The UDMM supplemented with EGF, IGF-I, and Cys resulted in higher proportions of cleavage, morula yields, and blastocyst yields (P < 0.05) than the DMM or SDMM supplemented with EGF + IGF-I + Cys. There was no significant difference between DMM and SDMM in the proportions of oocytes reaching the morula and blastocyst stages. In conclusion, an efficient system for in vitro production of sheep blastocysts was developed by using a defined oocyte maturation system combined with growth factors, hormones, and an antioxidant, but the UDMM resulted in higher cleavage, morula yields, and blastocyst yields than the DMM or SDMM.

The effect of growth hormone (GH) and insulin-like growth factor-I (IGF-I) on in vitro maturation of equine oocytes

Zygote ◽  
2011 ◽  
Vol 20 (4) ◽  
pp. 353-360 ◽  
Author(s):  
Gabriel Ribas Pereira ◽  
Pedro Luis Lorenzo ◽  
Gustavo Ferrer Carneiro ◽  
Barry Allen Ball ◽  
Paulo Bayard Dias Gonçalves ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Control Group ◽  
Factor I ◽  
Stage Of Development ◽  
Igf I ◽  
Group 15 ◽  
Cytoplasmic Maturation ◽  
Growth Factor I

SummaryThe objective of this study was to test the hypothesis that equine growth hormone (eGH), in combination with insulin growth factor-I (IGF-I), influences positively in vitro nuclear and cytoplasmic maturation of equine oocytes. Cumulus–oocyte complexes were recovered from follicles that were < 25 mm in diameter, characterized by morphology and were allocated randomly as follow: (a) control (no additives); (b) 400 ng/ml eGH; (c) 200 ng/ml IGF-I; (d) eGH + IGF-I; and (e) eGH + IGF-I + 400 ng/ml anti-IGF-I antibody. Oocytes were matured for 30 h at 38.5°C in air with 5% CO2 and then stained with 10 μg/ml propidium iodide (PI) to evaluate nuclear status and 10 μg/ml Lens culinaris agglutinin-fluorescein complex (FITC-LCA) to assess cortical granule migration by confocal microscopy. The proportion of immature oocytes that developed to the metaphase II (MII) stage in the eGH + IGF-I group (15 of 45) was greater than in the groups that were treated only with IGF-I (7 of 36, p = 0.03). Oocytes that reached MII in the control group (20 of 56; 35.7%) showed a tendency to be different when compared with eGH + IGF-I group (15 of 45; 33.3%, p = 0.08). The treated group that contained anti-IGF-I (15 of 33; 45.4%) decreased the number of oocytes reaching any stage of development when compared with eGH (47 of 72; 65.3%) and eGH + IGF-I (33 of 45; 73.3%) groups (p = 0.05) when data from MI and MII were combined. We concluded that the addition of eGH to in vitro maturation (IVM) medium influenced the in vitro nuclear and cytoplasmic maturation of equine oocytes. The use of GH and IGF-I in vitro may represent a potential alternative for IVM of equine oocytes.

Cyclic stretch regulates autocrine IGF-I in vascular smooth muscle cells: implications in vascular hyperplasia

1999 ◽  
Vol 276 (4) ◽  
pp. E697-E705 ◽  
Author(s):  
Paul R. Standley ◽  
Tamar J. Obards ◽  
Cherie L. Martina
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Systolic Hypertension ◽  
Cyclic Stretch ◽  
Cation Channels ◽  
Igf I

Vascular smooth muscle cells (VSMC) subjected to acute or chronic stretch display enhanced growth rates in vitro and in vivo. Clinical examples of vascular hyperplasia (e.g., systolic hypertension and postinjury restenosis) suggest that local insulin-like growth factor I (IGF-I) expression is enhanced. Therefore, we investigated the role of in vitro cyclic stretch on rat VSMC IGF-I secretion and cellular growth. In serum-free medium, cyclic stretch (1 Hz at 120% resting length for 48 h) stimulated thymidine incorporation ∼40% above that seen in nonstretched cells. Graded stretch magnitude (100–125% resting length) yielded graded increases in VSMC growth. Exogenous IGF-I increased growth of serum-starved, nonstretched VSMC in a dose-dependent manner, with maximal growth seen with 10−7 M. IGF-I secretion from stretched cells was 20- to 30-fold greater than from those cells cultured in a static environment. Stretch-induced increases in growth were completely blocked on addition of anti-IGF-I and partially blocked with platelet-derived growth factor (PDGF) antibodies and with a tyrosine kinase inhibitor (tyrphostin-1). Finally, blockade of stretch-activated cation channels with GdCl3 profoundly inhibited stretch-induced growth. We conclude that stretch increases VSMC IGF-I secretion and that such autocrine IGF-I is required for stretch-induced growth. PDGF and stretch-sensitive cation channels are likely additional components of a complex pathway that regulates stretch-induced VSMC seen in systolic hypertension and postinjury restenosis.

Longitudinal bone growth in vitro: effects of insulin-like growth factor I and growth hormone

1991 ◽  
Vol 124 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Ben A. A. Scheven ◽  
Nicola J. Hamilton
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Bone Growth ◽  
Long Bone ◽  
Long Bones ◽  
Insulin Like Growth Factor ◽  
Serum Free ◽  
Factor I ◽  
Igf I

Abstract. Longitudinal growth was studied using an in vitro model system of intact rat long bones. Metatarsal bones from 18- and 19-day-old rat fetuses, entirely (18 days) or mainly (19 days) composed of chondrocytes, showed a steady rate of growth and radiolabelled thymidine incorporation for at least 7 days in serum-free media. Addition of recombinant human insulin-like growth factor-I to the culture media resulted in a direct stimulation of the longitudinal growth. Recombinant human growth hormone was also able to stimulate bone growth, although this was generally accomplished after a time lag of more than 2 days. A monoclonal antibody to IGF-I abolished both the IGF-I and GH-stimulated growth. However, the antibody had no effect on the growth of the bone explants in control, serum-free medium. Unlike the fetal long bones, bones from 2-day-old neonatal rats were arrested in their growth after 1-2 days in vitro. The neonatal bones responded to IGF-I and GH in a similar fashion as the fetal bones. Thus in this study in vitro evidence of a direct effect of GH on long bone growth via stimulating local production of IGF by the growth plate chondrocytes is presented. Furthermore, endogenous growth factors, others than IGFs, appear to play a crucial role in the regulation of fetal long bone growth.

Effects of elevated blood insulin-like growth factor-I (IGF-I) concentration upon IGF-I in bovine mammary secretions during the colostrum phase

1993 ◽  
Vol 137 (2) ◽  
pp. 223-230 ◽  
Author(s):  
D. L. Hadsell ◽  
C. R. Baumrucker ◽  
R. S. Kensinger
Keyword(s):  
Growth Factor ◽  
Nutrient Restriction ◽  
Control Group ◽  
Insulin Like Growth Factor ◽  
Dry Period ◽  
Entire Treatment Period ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I ◽  
Serum Gh

ABSTRACT The objectives of these studies were to determine if the concentration of insulin-like growth factor-I (IGF-I) in mammary colostrum secretions could be altered through manipulation of IGF-I concentrations in blood and to compare the temporal changes of IGF-I in mammary secretions to those occurring for IgG1. Milking of 15 pregnant Holstein cows was stopped at 8 weeks prepartum and they were randomly assigned to one of three treatments. A control (C) treatment consisted of feeding the animals 100% of NRC requirements for protein and energy. A second group of cows was fed as the control group and injected with 1·8 μmol bovine GH/day. The third group was fed at 70% of NRC requirements for protein and energy to cause a moderate nutrient restriction (NR). Body weight was measured weekly. Blood was collected by tail venepuncture at 4 h intervals for 24 h. Mammary secretions were collected and pooled among contralateral front and rear quarters (diagonal) for measurement of volume, IGF-I and IgG1 concentrations. Samples were collected at −7, −5, −2, 0 and 1 week postpartum. Cows on the NR treatment failed to gain weight during the dry period compared with C cows (P < 0·05). Blood GH and IGF-I concentrations (P > 0·1) were unaffected by NR treatment. Cows treated with GH had higher (P < 0·01) serum GH and IGF-I levels throughout the entire treatment period, and higher serum IgG1 at 5 and 2 weeks prepartum (P < 0·01). Total mass of IGF-I secreted per diagonal averaged 3·6-fold greater for GH-treated cows during the prepartum period than C and NR cows (P < 0·01). The concentration of IGF-I in mammary secretions was not affected by treatment during the prepartum period, but was 40% greater (P < 0·05) in GH-treated cows than C and NR cows at parturition. Analysis of a selective index comparing IGF-I secretion with that of IgG1 suggested that IGF-I does not enter mammary secretions by passive diffusion from blood. Journal of Endocrinology (1993) 137, 223–230

scholarly journals In vitro analysis of the oligodendrocyte lineage in mice during demyelination and remyelination.

1990 ◽  
Vol 111 (3) ◽  
pp. 1183-1195 ◽  
Author(s):  
R Armstrong ◽  
V L Friedrich ◽  
K V Holmes ◽  
M Dubois-Dalcq
Keyword(s):  
Growth Factor ◽  
Glial Cells ◽  
Demyelinating Disease ◽  
Hepatitis Virus ◽  
Relative Proportion ◽  
Biological Properties ◽  
Murine Hepatitis Virus ◽  
Adult Mice ◽  
Igf I

A demyelinating disease induced in C57B1/6N mice by intracranial injection of a coronavirus (murine hepatitis virus strain A59) is followed by functional recovery and efficient CNS myelin repair. To study the biological properties of the cells involved in this repair process, glial cells were isolated and cultured from spinal cords of these young adult mice during demyelination and remyelination. Using three-color immunofluorescence combined with [3H]thymidine autoradiography, we have analyzed the antigenic phenotype and mitotic potential of individual glial cells. We identified oligodendrocytes with an antibody to galactocerebroside, astrocytes with an antibody to glial fibrillary acidic protein, and oligodendrocyte-type 2 astrocyte (O-2A) progenitor cells with the O4 antibody. Cultures from demyelinated tissue differed in several ways from those of age-matched controls: first, the total number of O-2A lineage cells was strikingly increased; second, the O-2A population consisted of a higher proportion of O4-positive astrocytes and cells of mixed oligodendrocyte-astrocyte phenotype; and third, all the cell types within the O-2A lineage showed enhanced proliferation. This proliferation was not further enhanced by adding PDGF, basic fibroblast growth factor (bFGF), or insulin-like growth factor I (IGF-I) to the defined medium. However, bFGF and IGF-I seemed to influence the fate of O-2A lineage cells in cultures of demyelinated tissue. Basic FGF decreased the percentage of cells expressing galactocerebroside. In contrast, IGF-I increased the relative proportion of oligodendrocytes. Thus, O-2A lineage cells from adult mice display greater phenotypic plasticity and enhanced mitotic potential in response to an episode of demyelination. These properties may be linked to the efficient remyelination achieved in this demyelinating disease.

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