Vasopressin stimulation of cell proliferation in the rat pituitary gland in vitro

1990 ◽  
Vol 126 (2) ◽  
pp. 255-259 ◽  
Author(s):  
A. M. McNicol ◽  
J. E. Murray ◽  
W. McMeekin
Keyword(s):  
Growth Factor ◽  
Test System ◽  
Pituitary Cells ◽  
Short Term ◽  
Corticotrophin Releasing Factor ◽  
Rat Pituitary ◽  
Epidermal Growth ◽  
Short Term Culture ◽  
Stimulation Of

ABSTRACT Proliferative activity was measured in rat anterior pituitary cells in short-term culture by calculating the labelling index (LI), based on the immunohistochemical detection of cells incorporating the thymidine analogue bromodeoxyuridine. Basal LI was reproducible in the test system. Arginine vasopressin (AVP) induced a dose-related increase in LI up to 20 ng/ml. Corticotrophin-releasing factor-41 (CRF-41) had no effect at doses up to 20 ng/ml. However, in the presence of 10 ng CRF-41/ml, AVP induced a greater increase in LI at lower doses than did AVP alone. Fibroblast growth factor also induced a significant increase in LI. In the system used, epidermal growth factor and insulin had no effect on proliferation. Journal of Endocrinology (1990) 126, 255–259

scholarly journals Epidermal growth factor, like glucagon, exerts a short-term stimulation of alanine transport in rat hepatocytes

1987 ◽  
Vol 247 (1) ◽  
pp. 233-235 ◽  
Author(s):  
S K Moule ◽  
J D McGivan
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Membrane ◽  
Rat Hepatocytes ◽  
Short Term ◽  
Membrane Hyperpolarization ◽  
Control Value ◽  
Alanine Transport ◽  
Epidermal Growth ◽  
Stimulation Of

Epidermal growth factor causes a transient stimulation of alanine transport in hepatocytes. The stimulation is maximal after 30 min, and the rate returns to the control value after 90 min. These characteristics are very similar to the short-term stimulation of alanine transport by glucagon, which has been attributed to cell membrane hyperpolarization.

Acute effects of epidermal growth factor on Na+, K+-ATPase-dependent oxygen consumption and the amount of the enzyme units in enterocytes isolated from the jejunum of chickens

1998 ◽  
Vol 78 (3) ◽  
pp. 327-333 ◽  
Author(s):  
H. Park ◽  
B. W. McBride ◽  
L. P. Milligan ◽  
L. M. Trouten-Radford
Keyword(s):  
Oxygen Consumption ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Intracellular Ph ◽  
Basolateral Membrane ◽  
Fixed Number ◽  
Short Term ◽  
Key Words Oxygen Consumption ◽  
Epidermal Growth

Enterocytes from jejunum of male White Leghorn chickens aged 14 d and 20 wk were used to investigate the short-term effect of epidermal growth factor (EGF) on total O2 uptake (TO2) and Na+, K+-dependent O2 uptake (OSO2) and intracellular pH (pHi). Total O2 uptake and OSO2 was decreased (P < 0.05) in enterocytes, isolated from both young and adult birds as concentration of EGF increased in the incubation medium from 0 to 100 ng mL−1. The energy required to support Na+, K+-ATPase activity in jejunal enterocytes obtained from 2-wk-old and 20-wk-old birds was 33–37% and 31–34% of total O2 uptake, respectively. No changes were observed in the amount of the maximal binding sites for 3H-ouabain in enterocytes incubated with EGF; the regulation had not caused rapid decrease in the amount of Na+, K+-ATPase units in the basolateral membrane of enterocytes. Epidermal growth factor caused short-term reduction of pHi as did amiloride. Seemingly, an acute action of EGF in chicken enterocytes in vitro is to reduce the activity of a fixed number of Na+, K+-ATPase units in enterocytes by decreasing Na+, H+-antiport-dependent Na+ influx. Key words: Oxygen consumption, enterocytes, Na+, K+-ATPase, ouabain, epidermal growth factor, intracellular pH, chicks

scholarly journals Lack of correlation between changes in polyphosphoinositide levels and actin/gelsolin complexes in A431 cells treated with epidermal growth factor.

1991 ◽  
Vol 112 (6) ◽  
pp. 1151-1156 ◽  
Author(s):  
C Y Dadabay ◽  
E Patton ◽  
J A Cooper ◽  
L J Pike
Keyword(s):  
Growth Factor ◽  
Actin Cytoskeleton ◽  
Actin Polymerization ◽  
Inositol Phosphates ◽  
A431 Cells ◽  
Pi Turnover ◽  
Epidermal Growth ◽  
Stimulation Of

The polyphosphoinositides, PIP and PIP2, have been proposed to regulate actin polymerization in vivo because they dissociate actin/gelsolin complexes in vitro. We tested this hypothesis by comparing the ability of EGF and bradykinin to affect PI metabolism and the actin cytoskeleton in A431 cells. EGF, but not bradykinin, was found to induce ruffling and dissociation of actin/gelsolin complexes in these cells. However, both EGF and bradykinin stimulated the accumulation of inositol phosphates in [3H]inositol-labeled cells indicating that stimulation of PI turnover is not sufficient for the induction of changes in actin/gelsolin complex levels. EGF stimulated a twofold increase in the level of PIP in A431 cells. Other phosphoinositide levels were not markedly altered. Treatment of the cells with cholera toxin abrogated the EGF-induced rise in PIP levels without altering the dissociation of actin from gelsolin. These data indicate that increases in PIP and/or PIP2 are not necessary for dissociation of actin/gelsolin complexes. Overall, these experiments suggest that in A431 cells, the effects of EGF on the actin cytoskeleton are unlikely to be mediated through changes in PIP or PIP2 levels.

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