Growth Regulation of Human Thyrocytes by Thyrotropin, Cyclic Adenosine Monophosphate, Epidermal Growth Factor and Insulin-Like Growth Factor

2015 ◽  
pp. 56-80 ◽  
Author(s):  
Peter E. Goretzki ◽  
Andrea Frilling ◽  
Dietmar Simon ◽  
Massoud Rastegar ◽  
Christian Ohmann
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Regulation ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Insulin Like Growth Factor ◽  
Epidermal Growth

Epidermal growth factor stimulates the prolactin synthesis and secretion in rat pituitary cells in culture (GH4C1 cells) by increasing the intracellular concentration of free calcium

1993 ◽  
Vol 128 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Marie Aanestad ◽  
J Sigurd Røtnes ◽  
Peter A Torjesen ◽  
Egil Haug ◽  
Olav Sand ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Intracellular Concentration ◽  
Free Calcium ◽  
Pituitary Cells ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Epidermal Growth

Epidermal growth factor (EGF) stimulated the prolactin (PRL) synthesis and release from the GH4C1 cells in a dose-dependent manner. The ED50 was between 10−11 and 10−10 mol/l. The maximal effect was obtained at 10−9 mol/l EGF for the release, and 10−8 mol/l EGF for the synthesis. EGF stimulated the release of PRL from cell perfusion columns after a lag period of about 30 s. The maximal secretion of PRL occurred about 60 s after the start of stimulation. The PRL secretion declined to basal levels within 2 min. The EGF-stimulated PRL release was additive to the secretion evoked by thyrotropin-releasing hormone (TRH) and vasoactive intestinal peptide (VIP). An instantaneous increase in the intracellular concentration of free calcium, [Ca2+]i, of the GH4C1 cells was observed after the administration of EGF. EGF modified neither the basal nor the TRH-stimulated inositoltrisphosphate production in the GH4C1 cells, and EGF did not show any effect on the cyclic adenosine monophosphate production of these cells.

scholarly journals Reversible meiotic arrest in feline oocytes

2014 ◽  
Vol 26 (2) ◽  
pp. 258 ◽  
Author(s):  
Jason R. Herrick
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Blastocyst Stage ◽  
Chorionic Gonadotrophin ◽  
Developmental Competence ◽  
Camp Production ◽  
Cumulus Oocyte Complex ◽  
Epidermal Growth

Increasing intracellular concentrations of cyclic adenosine monophosphate (cAMP) within the cumulus–oocyte complex (COC) inhibits or delays spontaneous oocyte maturation and improves the developmental competence of the oocyte in many species, but information for carnivores is limited. The objectives of the present study were to describe the effects of isobutyl methylxanthine (IBMX), which decreases cAMP degradation, and forskolin, which increases cAMP production, on spontaneous and induced maturation (by equine chorionic gonadotrophin (eCG) and epidermal growth factor (EGF)) of feline oocytes and to evaluate the reversibility of IBMX-induced arrest by measuring the resumption of meiosis and embryonic development following IVF. IBMX decreased (P < 0.05) the incidence of spontaneous (6.7% vs 42.0%, metaphase II (MII)) and induced (5.6% vs 66.1% MII) maturation after 24 h of culture. In contrast, forskolin stimulated meiosis (81.7% MII; P < 0.05). Following 12 h of culture with IBMX and an additional 24 h with eCG and EGF in the absence of IBMX, the proportions of oocytes reaching MII (66.1%), cleaving (79.9%) and developing to the blastocyst stage (15.3%) were similar (P > 0.05) to oocytes cultured continuously with eCG and EGF (70.2%, 83.0% and 18.1%, respectively). These results demonstrate that IBMX reversibly inhibits both spontaneous and eCG+EGF-induced meiosis in feline oocytes without compromising the oocyte’s developmental competence.

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