Effects of glucocorticosteroids on prolactin and growth hormone production and characterization of the intracellular hormone receptors in rat pituitary tumour cells

1980 ◽  
Vol 95 (3) ◽  
pp. 319-327 ◽  
Author(s):  
Oddvar Naess ◽  
Egil Haug ◽  
Kaare Gautvik
Keyword(s):  
Growth Hormone ◽  
Hormone Receptors ◽  
Pituitary Tumour ◽  
Tumour Cells ◽  
Scatchard Analysis ◽  
Hormone Production ◽  
Single Class ◽  
High Affinity ◽  
Rat Pituitary

Abstract. The effect of corticosterone and dexamethasone on the production of growth hormone and prolactin was studied in rat pituitary tumour cells (GH3-cells) in culture. Corticosterone and dexamethasone caused a dose-dependent stimulation of growth hormone synthesis, and the highest concentration (10−6 mol/l) increased growth hormone levels to 250% of controls. This concentration, however, decreased prolactin synthesis to 25% of the control values. The cytosol fractions from monolayer cultures as well as from tumours of GH3-cells were found to possess receptor molecules for glucocorticoid hormones, having a sedimentation constant close to 8 S in a salt-free buffer and 4 S in the presence of 0.5 mol/l KCL. Isoelectric point of the receptor was 5.8. Scatchard analysis showed one single class of binding sites with high affinity (Kd 2.1 ± 0.4 (sd × 10−9 mol/l). Studies on the steroid specificity revealed that dexamethasone had the highest affinity for the receptor. Corticosterone, cortisol and progesterone had also high affinity, whereas testosterone and oestradiol-17β had no significant affinity for the receptors. After in vivo administration of [3H]dexamethasone to GH3 tumour-bearing rats, radioactivity could be extracted from purified nuclei bound to 4 S macromolecules. The presence of receptors for glucocorticosteroid hormones in the GH3-cells, suggests that these hormones may alter growth hormone and prolactin production at the anterior pituitary level.

Specific antisense RNA inhibition of growth hormone production in differentiated rat pituitary tumour cells

1990 ◽  
Vol 171 (1) ◽  
pp. 293-300 ◽  
Author(s):  
Ruth H. Paulssen ◽  
Eyvind J. Paulssen ◽  
Peter Aleström ◽  
Jan O. Gordeladze ◽  
Kaare M. Gautvik
Keyword(s):  
Growth Hormone ◽  
Antisense Rna ◽  
Pituitary Tumour ◽  
Tumour Cells ◽  
Hormone Production ◽  
Inhibition Of Growth ◽  
Rat Pituitary ◽  
Rna Inhibition

Progestin receptors in prolactin and growth hormone producing tumours in rats

1982 ◽  
Vol 100 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Oddvar Naess ◽  
Egil Haug ◽  
Arne Attramadal ◽  
Kaare M. Gautvik
Keyword(s):  
Growth Hormone ◽  
Glucocorticoid Receptors ◽  
Progesterone Receptors ◽  
Pituitary Tumour ◽  
Tumour Cells ◽  
Female Rats ◽  
Progestin Receptors ◽  
High Affinity ◽  
Protein Nature ◽  
Specific Receptors

Abstract. Progesterone and corticosterone have a similar effect on the production of growth hormone (GH) and prolactin (Prl) by pituitary tumour cells (GH3 cells) in culture. Previously we have shown that progesterone has a high affinity for the glucocorticoid receptors in these cells. Progesterone may therefore exert its effects through binding to the glucocorticoid receptor. The aim of the present study was to investigate if the GH3 tumour cells and an oestrogen induced pituitary tumour, which also produce GH and Prl, possess specific receptors for progesterone. Both the GH3 tumours and the oestrogen induced pituitary tumour were in fact found to possess cytoplasmatic receptor molecules for progesterone by using the potent progestin R5020 as a marker. Isoelectric focusing revealed one binding component (pH 5.9), which was of protein nature. The binding was of high affinity (Kd 2 × 10−9 mol/l). In the oestrogen induced tumour, the maximal binding was 70 fmol/mg cytosol protein. In female rats with GH3 tumours the binding was 55 fmol/mg cytosol protein. Priming of the animals with 1 mg oestradiol-valerate increased the binding to 116 fmol/mg cytosol protein, whereas very little binding was found in GH3 tumours from rats castrated 7 days before sacrifice. The receptors in the oestrogen induced pituitary tumour and the GH3 tumours exhibited high affinity for R5020 and progesterone, whereas corticosterone had no significant affinity for the receptors. Using exchange assay, it was demonstrated that the cytoplasmic progestin receptors could be translocated to the nucleus after administration of progesterone to the animals. Thus, the presence of specific progesterone receptors, different from the glucocorticoid receptors, strongly indicates that the effects of progesterone on GH and Prl production are mediated through the progesterone receptors.

scholarly journals Human chorionic somatomammotropin and growth hormone gene expression in rat pituitary tumour cells is dependent on proximal promoter sequences

1989 ◽  
Vol 17 (11) ◽  
pp. 4327-4337 ◽  
Author(s):  
Mark W. Nachtigal ◽  
Barbara E. Nickel ◽  
Margaret E. Klassen ◽  
Wengang Zhang ◽  
Norman L. Eberhardt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Pituitary Tumour ◽  
Tumour Cells ◽  
Proximal Promoter ◽  
Growth Hormone Gene ◽  
Promoter Sequences ◽  
Rat Pituitary ◽  
Chorionic Somatomammotropin

Growth hormone receptors in the liver and osmoregulatory organs of rainbow trout: characterization and dynamics during adaptation to seawater

1991 ◽  
Vol 130 (3) ◽  
pp. 425-433 ◽  
Author(s):  
T. Sakamoto ◽  
T. Hirano
Keyword(s):  
Growth Hormone ◽  
Rainbow Trout ◽  
Binding Sites ◽  
Chum Salmon ◽  
Hormone Receptors ◽  
Sea Water ◽  
Specific Binding ◽  
Head Kidney ◽  
Scatchard Analysis ◽  
Single Class

ABSTRACT Specific binding sites for chum salmon growth hormone (sGH) were identified in the membranes obtained from tissues of rainbow trout. Specific binding of 125I-labelled sGH (% per mg protein) was found in the liver (37%), ovary (6%), brain (6%), gill (4%), intestine (4%) and posterior body kidney (4%). Specific binding was not significant in head kidney, anterior body kidney, spleen, heart, skeletal muscle or skin. Scatchard analyses demonstrated the presence of a single class of high-affinity low-capacity receptors in the liver, gill, intestine and kidney. The association constants for the membranes from liver, gill, intestine and kidney were of the same order (1 litre/nmol). Chum salmon prolactin did not inhibit the binding of 125I-labelled sGH to receptors in the liver, gill, intestine and kidney. Transfer of rainbow trout from fresh water to 80% seawater evoked a rise in plasma concentration of GH and a significant decrease in the GH binding to the liver membranes after 1 day. Binding in the gill and kidney was not altered significantly. Membranes were treated with 4 mol MgCl2/l to remove bound GH from the receptors, and the results indicated that the reduction in binding in the liver after transfer to sea-water was probably due to receptor occupancy by increased endogenous GH. The occupancy of liver GH-binding sites was maximal 4 days after transfer. Total (MgCl2-treated) binding sites in the liver increased significantly 14 days after transfer. Scatchard analysis indicated that receptors were altered in capacity without changes in binding affinity. Although GH may also directly affect osmoregulatory organs through their GH receptors, the present results indicate the likelihood of at least partial mediation by the liver of the seawater-adapting action of GH in the rainbow trout. Journal of Endocrinology (1991) 130, 425–433

Differential effects of extracellular matrix on secretion of prolactin and growth hormone by rat pituitary tumour cells in vitro

1985 ◽  
Vol 108 (2) ◽  
pp. 156-160 ◽  
Author(s):  
R. A. Prysor-Jones ◽  
J. J. Silverlight ◽  
J. S. Jenkins
Keyword(s):  
Growth Hormone ◽  
Extracellular Matrix ◽  
Corneal Endothelium ◽  
Pituitary Tumour ◽  
Tumour Cells ◽  
Cell Protein ◽  
Thyrotrophin Releasing Hormone ◽  
Rate Of Spread ◽  
Rat Pituitary

Abstract. Two types of rat pituitary tumour cells secreting both prolactin (Prl) and growth hormone (GH) were cultured in vitro either on plastic dishes or on surfaces coated with an extracellular matrix (ECM) derived from bovine corneal endothelium. The presence of ECM caused an increase in Prl but a decrease in GH. On one cell line the Prl response to thyrotrophin releasing hormone (TRH) was increased by ECM. There was an increase in the rate of spread of the cultures, an increase in cell protein, and DNA synthesis and a change in cell morphology when ECM was used. It is suggested that these observations can be explained by a sensitizing action of ECM to growth factors present in serum.

Characterization of gonadotropin-releasing hormone receptors in goldfish ovary: variation during follicular development

1993 ◽  
Vol 264 (2) ◽  
pp. R227-R234 ◽  
Author(s):  
D. Pati ◽  
H. R. Habibi
Keyword(s):  
Binding Sites ◽  
Hormone Receptors ◽  
Tissue Concentration ◽  
High Capacity ◽  
Follicular Development ◽  
Gonadotropin Releasing Hormone ◽  
Scatchard Analysis ◽  
Single Class ◽  
Releasing Hormone ◽  
High Affinity

Gonadotropin-releasing hormone (GnRH) receptors were characterized in the goldfish ovary using an analogue of salmon GnRH ([D-Arg6,Trp7,Leu8,Pro9-NEt]GnRH; sGn-RH-A) as a labeled ligand. Binding of sGnRH-A to goldfish follicular membrane preparation was found to be saturable, reversible, and dependent on time, temperature, tissue concentration, and pH. Addition of unlabeled sGnRH-A displaced the bound 125I-labeled sGnRH-A in a dose-related manner. Hill plot as well as Scatchard analysis indicated the presence of two classes of binding sites, a high-affinity/low-capacity site and a low-affinity/high-capacity site, in the fully mature and less mature goldfish ovary. However, immature goldfish ovary contained only a single class of low-affinity binding sites. The equilibrium association constants (Ka) of the low-affinity sites were found to be similar in all follicular groups. However, there was a tendency for a higher Ka value of the high-affinity sites in the less mature follicles (0.5-0.95 mm) compared with the fully mature follicles (1.11-1.48 mm), although the differences were not statistically significant. Bound 125I-sGnRH-A was also found to be displaceable by sGnRH ([Trp7,Leu8]GnRH) and chicken GnRH-II (cGnRH-II; [His5,Trp7,Tyr8]GnRH), which occur naturally in the goldfish brain. sGnRH-A and cGnRH-II were found to bind with greater affinity than sGnRH to the goldfish ovarian GnRH binding sites.

EFFECTS OF SEX STEROIDS ON GROWTH HORMONE PRODUCTION IN CULTURED RAT PITUITARY CELLS

1978 ◽  
Vol 87 (1) ◽  
pp. 40-54 ◽  
Author(s):  
E. Haug ◽  
K. M. Gautvik
Keyword(s):  
Growth Hormone ◽  
Sex Steroids ◽  
Pituitary Tumour ◽  
Maximum Effect ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Thyrotrophin Releasing Hormone ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Dose Dependent

ABSTRACT Monolayer cultures of rat pituitary tumour cells (GH3) were used to study the effects of different sex steroids on growth hormone (GH) production expressed as the amount of extracellular hormone which accumulated during 24 h. The hormone was measured with a sensitive and specific radioimmunoassay. Oestradiol-17β (10−12 mol/l—10−6 mol/l) caused a dose-dependent decrease in GH production with the maximum effect (30 % of controls) at 10−10 mol/l. After the cessation of treatment with oestradiol-17β (10−8 mol/l for 7 days), control levels of GH were obtained within 11 days, after a transient augmentation of production. Progesterone (10−11–10−6 mol/l) caused a dose-dependent stimulation of GH production, and the maximum effect (160 % of controls) was observed at 10−6 mol/l. Testosterone (10−6 mol/l) decreased the production of GH to 70 % of control values, whereas 5α-dihydrotestosterone (DHT) had no effect. Cell growth was not affected by any of the sex steroids. Corticosterone (10−6 mol/l) increased GH production to about 400 % of control values, and this effect was inhibited by oestradiol-17β (10−6 mol/l). The hypothalamic peptides, thyrotrophin releasing hormone (TRH) and somatostatin, that both depressed GH production did not significantly inhibit the stimulatory effect of corticosterone. When used in combination, the effects of oestradiol-17β (10−6 mol/l) and TRH (3 × 10−7 mol/l) were additive which was not the case for the combination oestradiol-17β (10−6 mol/l) and testosterone (10−6 mol/l). These results suggest different mechanisms of action of peptide and steroid hormones on GH production in the GH3 cells. If the properties of the GH3 cells reflect those of normal somatotrophs the sex steroids may alter GH production at the pituitary level, an influence that may be further modulated by corticoids, TRH and somatostatin.

THE PRESENCE OF BIOSYNTHETIC PRECURSORS AND HETEROGENEOUS MESSENGER RNAs FOR PROLACTIN IN CULTURED RAT PITUITARY TUMOUR CELLS

1983 ◽  
Vol 104 (2_Supplb) ◽  
pp. S66-S69
Author(s):  
P. Aleström ◽  
E.J. Paulssen ◽  
V. Gautvik ◽  
M. Kriz ◽  
E. Haug ◽  
...  
Keyword(s):  
Pituitary Tumour ◽  
Tumour Cells ◽  
Messenger Rnas ◽  
Rat Pituitary
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