scholarly journals Growth Hormone and Epidermal Growth Factor in Salivary Glands of Giant and Dwarf Transgenic Mice

2004 ◽  
Vol 52 (9) ◽  
pp. 1191-1197 ◽  
Author(s):  
William G. Young ◽  
German O. Ramirez-Yañez ◽  
Terry J. Daley ◽  
Joseph R. Smid ◽  
Karen T. Coshigano ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transgenic Mice ◽  
Salivary Glands ◽  
Epidermal Growth

scholarly journals Attenuation of epidermal growth factor (EGF) signaling by growth hormone (GH)

2017 ◽  
Vol 233 (2) ◽  
pp. 175-186 ◽  
Author(s):  
Lorena González ◽  
Johanna G Miquet ◽  
Pablo E Irene ◽  
M Eugenia Díaz ◽  
Soledad P Rossi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Hormone ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transgenic Mice ◽  
Mitogen Activated Protein Kinase ◽  
Compensatory Mechanism ◽  
Similar Response ◽  
Epidermal Growth ◽  
Egf Signaling

Transgenic mice overexpressing growth hormone (GH) show increased hepatic protein content of the epidermal growth factor receptor (EGFR), which is broadly associated with cell proliferation and oncogenesis. However, chronically elevated levels of GH result in desensitization of STAT-mediated EGF signal and similar response of ERK1/2 and AKT signaling to EGF compared to normal mice. To ascertain the mechanisms involved in GH attenuation of EGF signaling and the consequences on cell cycle promotion, phosphorylation of signaling mediators was studied at different time points after EGF stimulation, and induction of proteins involved in cell cycle progression was assessed in normal and GH-overexpressing transgenic mice. Results from kinetic studies confirmed the absence of STAT3 and 5 activation and comparable levels of ERK1/2 phosphorylation upon EGF stimulation, which was associated with diminished or similar induction of c-MYC, c-FOS, c-JUN, CYCLIN D1 and CYCLIN E in transgenic compared to normal mice. Accordingly, kinetics of EGF-induced c-SRC and EGFR phosphorylation at activating residues demonstrated that activation of these proteins was lower in the transgenic mice with respect to normal animals. In turn, EGFR phosphorylation at serine 1046/1047, which is implicated in the negative regulation of the receptor, was increased in the liver of GH-overexpressing transgenic mice both in basal conditions and upon EGF stimulus. Increased basal phosphorylation and activation of the p38-mitogen-activated protein kinase might account for increased Ser 1046/1047 EGFR. Hyperphosphorylation of EGFR at serine residues would represent a compensatory mechanism triggered by chronically elevated levels of GH to mitigate the proliferative response induced by EGF.

Interaction of Growth Hormone-Releasing Factor and Somatostatin on Ulcer Healing and Mucosal Growth in Rats: Role of Gastrin and Epidermal Growth Factor

Digestion ◽  
1988 ◽  
Vol 41 (3) ◽  
pp. 121-128 ◽  
Author(s):  
S.J. Konturek ◽  
T. Brzozowski ◽  
A. Dembinski ◽  
Z. Warzecha ◽  
P.K. Konturek ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Ulcer Healing ◽  
Growth Hormone Releasing Factor ◽  
Epidermal Growth ◽  
Mucosal Growth

Effect of sialoadenectomy on ethanol-induced gastric mucosal damage in the rat: role of neutrophils

1990 ◽  
Vol 68 (2) ◽  
pp. 207-210 ◽  
Author(s):  
B. L. Tepperman ◽  
B. D. Soper
Keyword(s):  
Growth Factor ◽  
Gastric Mucosa ◽  
Epidermal Growth Factor ◽  
Salivary Glands ◽  
Mucosal Damage ◽  
Gastric Mucosal Damage ◽  
Mucosal Inflammation ◽  
Prostaglandin E ◽  
Epidermal Growth ◽  
Extent Of Damage

We have observed that removal of the salivary glands is associated with an increase in the susceptibility to gastric mucosal damage in the rat. In the present study, we have examined the effect of sialoadenectomy on ethanol-induced mucosal hemorrhagic damage and myeloperoxidase (MPO) activity. Hemorrhagic damage and MPO activity in response to intragastric 50% w/v ethanol were greater in sialoadenectomized rats when compared with sham-operated animals. Pretreatment with 16,16-dimethylprostaglandin E2 (0.3 μg/kg s.c.) reduced damage and MPO activity in both sialoadenectomized and sham control rats receiving 50% ethanol. The reduction in these parameters was greater in control than in sialoadenectomized rats. Pretreatment with epidermal growth factor (5 μg/kg s.c.) significantly reduced MPO activity but did not significantly affect the extent of damage. These data suggest that sialoadenectomy is associated with an increase in mucosal inflammation in animals given ethanol. However, in some situations tissue inflammation (as indicated by MPO activity) was reduced, while the proportion of gastric mucosa exhibiting hemorrhagic damage was not changed.Key words: salivary glands, gastric mucosa, neutrophils, prostaglandin E2, epidermal growth factor.

scholarly journals Prolactin, Growth Hormone, and Epidermal Growth Factor Activate Stat5 in Different Compartments of Mammary Tissue and Exert Different and Overlapping Developmental Effects

2001 ◽  
Vol 229 (1) ◽  
pp. 163-175 ◽  
Author(s):  
Marta I. Gallego ◽  
Nadine Binart ◽  
Gertraud W. Robinson ◽  
Ryugo Okagaki ◽  
Karen T. Coschigano ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mammary Tissue ◽  
Developmental Effects ◽  
Epidermal Growth

Changes in protein metabolism of ovine primary muscle cultures on treatment with growth hormone, insulin, insulin-like growth factor I or epidermal growth factor

1987 ◽  
Vol 112 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J. M. M. Harper ◽  
J. B. Soar ◽  
P. J. Buttery
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Muscle Cultures ◽  
Epidermal Growth ◽  
Growth Factor I ◽  
High Concentrations

ABSTRACT Methods for the primary culture of muscle cells from fetal sheep were developed which gave high yields of cells. Myoblasts were grown in vitro, and allowed to fuse to form contractile multinucleate myotubes; these could be maintained in a good condition for at least 2 weeks. Protein turnover in these differentiated cultures was examined for sensitivity to each of four potentially anabolic peptide hormones and growth factors: insulin, insulin-like growth factor I (somatomedin C), epidermal growth factor and growth hormone. Insulin was found to have no effect except at high concentrations (1 μmol/l), compatible with its role as a somatomedin analogue. Insulin-like growth factor I was active at lower levels (1 nmol/l) but the cultures were not as responsive to it as were primary rat muscle cultures or differentiated L6 cells, which were tested in similar experiments. The maximum stimulation of protein synthesis observed with the ruminant system was only 16%. Epidermal growth factor was highly anabolic for primary cultures from sheep muscle, and the cells were very sensitive to it, half-maximal stimulation of protein synthesis being seen with concentrations as low as 20 pmol/l. No effects of bovine growth hormone were seen in the ovine system. However, an inhibition of protein breakdown was found with high concentrations (0·1 μmol/l) in the L6 rat myoblast cell line. It was found that the culture conditions used could affect the observed responses of protein synthesis and degradation, despite withdrawal of serum from the incubation media 22 h before testing. J. Endocr. (1987) 112, 87–96

Epidermal Growth Factor Stimulates Growth Hormone Secretion from Superfused Rat Adenohypophyseal Fragments

Endocrinology ◽  
1984 ◽  
Vol 115 (2) ◽  
pp. 556-558 ◽  
Author(s):  
HITOSHI IKEDA ◽  
TOMOAKI MITSUHASHI ◽  
KEN KUBOTA ◽  
NOBUAKI KUZUYA ◽  
HIDEMASA UCHIMURA
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Epidermal Growth
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