GROWTH IN MONOLAYER CULTURE OF RAT PITUITARY CELLS WHICH SYNTHETIZE AND RELEASE ACTH

1975 ◽  
Vol 79 (3) ◽  
pp. 421-430 ◽  
Author(s):  
R. E. Lang ◽  
I. Hilwig ◽  
K. H. Voigt ◽  
H. L. Fehm ◽  
E. F. Pfeiffer
Keyword(s):  
Pituitary Gland ◽  
Monolayer Culture ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Antibody Technique ◽  
Gland Cells ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Dose Dependent ◽  
Acth Release

ABSTRACT Cultures of rat pituitary gland cells were developed to study biosynthesis and release of ACTH. ACTH measurement was accomplished by radioimmunoassay. ACTH release was observed following stimulation with theophylline and cAMP in a dose-dependent manner. Biosynthesis was demonstrated by incorporation of 3H-phenylalanine into the hormone, employing a double antibody technique.

scholarly journals CircAgtpbp1 Acts as a Molecular Sponge of miR-543-5p to Regulate the Secretion of GH in Rat Pituitary Cells

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 558
Author(s):  
ZeWen Yu ◽  
WenZhi Ren ◽  
Tian Wang ◽  
WeiDi Zhang ◽  
ChangJiang Wang ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Inhibitory Effect ◽  
Pituitary Cells ◽  
Sequencing Analysis ◽  
Hormone Regulation ◽  
Gh Secretion ◽  
Qrt Pcr ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

CircRNAs have been identified to be expressed differently and stably in numerous species and tissues, but their functions in growth hormone (GH) secretion are still largely unknown. In summary, we have revealed a circRNA-miRNA-mRNA network that may play a biological role in the rat pituitary gland. First, we verified the chromosome location information of circAgtpbp1 according to sequencing analysis. The circAgtpbp1 characteristics were authenticated through PCR, qRT–PCR, treating with RNase and fluorescent in situ hybridization (FISH). Second, we detected the expression pattern of circAgtpbp1 in the rat anterior pituitary by qRT–PCR. We also designed circAgtpbp1 siRNA and constructed overexpression plasmid to evaluate the effect of circAgtpbp1 function on GH secretion by qRT–PCR, ELISA and Western blot. CircAgtpbp1 is a stable, truly circular molecule. We found that circAgtpbp1 interacted with miR-543-5p and can regulate GH secretion in pituitary cells through a circAgtpbp1-miR-543-5p-GH axis. Overall, the evidence generated by our study suggests that circAgtpbp1 can act as a sponge of miR-543-5p to reduce the inhibitory effect of miR-543-5p on Gh1 and further promote GH secretion. These findings expand our existing knowledge on the mechanisms of hormone regulation in the pituitary gland.

In vitro evidence of a role for inhibin in female rabbits

1984 ◽  
Vol 246 (3) ◽  
pp. E243-E248
Author(s):  
A. L. Goodman
Keyword(s):  
Granulosa Cells ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
C Cells ◽  
Rat Pituitary ◽  
Reference Preparation ◽  
Lh Release ◽  
Rat Pituitary Cells ◽  
I Cells

To examine a regulatory role for inhibin in female rabbits, an in vitro bioassay for inhibin activity was modified to use cultured rabbit pituitary cells and charcoal-extracted porcine follicular fluid (pFFx) as a reference preparation. pFFx inhibited follicle-stimulating hormone (FSH) release in a dose-dependent manner in cultures from both intact (I) and castrate (C) does at doses that also inhibited FSH release by cultured rat pituitary cells. Basal FSH release by I cells was inhibited greater than 10% by 0.02% (vol/vol) and greater than 90% by greater than or equal to 0.2% pFFx, whereas in C cells maximal inhibition of FSH release plateaued at only approximately 75%. FSH secretion was restored after removal of pFFx in day 2 media. Luteinizing hormone (LH) release by C cells was not inhibited at any dose of pFFx, but in I cells LH was progressively inhibited to approximately 60% of control levels during day 2 (but not day 1). Charcoal-extracted media (0.25-1%) in which 5 X 10(5) rabbit granulosa cells had been earlier cultured for 72 h produced a parallel inhibition of FSH release. The present findings demonstrate that 1) rabbit pituitary cells are responsive to inhibin, i.e., pFFx preferentially inhibited FSH secretion in a direct, graded, and reversible manner and 2) rabbit follicular granulosa cells secrete an inhibin-like substance.

Oxytocin has a role in gonadotrophin regulation in rats

1990 ◽  
Vol 125 (3) ◽  
pp. 425-432 ◽  
Author(s):  
G. Robinson ◽  
J. J. Evans
Keyword(s):  
Follicular Development ◽  
Pituitary Cells ◽  
Lh Surge ◽  
Rat Pituitary ◽  
Lh Release ◽  
Rat Pituitary Cells ◽  
Dose Dependent ◽  
In Vivo Administration

ABSTRACT We previously demonstrated that oxytocin stimulates LH release from rat pituitary cells in vitro and advances follicular development and ovulation in mice in vivo. This study reports an investigation of rat LH levels following in-vivo administration of oxytocin. Injection of oxytocin (10 mIU/g, i.p.) to rats at 07.00, 08.00 and 09.00 h of pro-oestrus or at 09.00, 10.00 and 11.00 h of pro-oestrus advanced the onset of the LH surge (P<0.005) and attainment of peak concentrations of LH (P<0.02) in peripheral blood. On the other hand, the descending phase of the LH surge and the surge amplitude were not altered by oxytocin. Treatment at 05.00, 06.00 and 07.00 h of pro-oestrus or at 11.00, 12.00 and 13.00 h of pro-oestrus had no effect on the LH profile. A higher oxytocin dose (20 mIU/g) inhibited LH release when treatment was begun at 05.00, 07.00 or 09.00 h of pro-oestrus. A lower dose (5 mIU/g) was ineffective in altering LH concentrations. In addition, injections of oxytocin (10 mIU/g) at oestrus, metoestrus or dioestrus had no effect on the release of LH. Thus the efficacy of oxytocin in altering concentrations of LH was dose dependent and also critically affected by the day of the oestrous cycle and the time of pro-oestrus. Removal of endogenous oxytocin activity by the use of an oxytocin receptor antagonist abolished the pro-oestrous LH surge, indicating that oxytocin is a vital physiological component of the LH-releasing mechanism in rats. The study provides unequivocal evidence that oxytocin induces LH release in vivo, but the manifestation of oxytocin activity is dependent upon conditions of exposure. Journal of Endocrinology (1990) 125, 425–432

scholarly journals Pharmacological characterisation of a new oral GH secretagogue, NN703

1999 ◽  
pp. 180-189 ◽  
Author(s):  
BS Hansen ◽  
K Raun ◽  
KK Nielsen ◽  
PB Johansen ◽  
TK Hansen ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Inositol Phosphate ◽  
Body Weight Gain ◽  
The Body ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Orally Active

NN703 is a novel orally active GH secretagogue (GHS) derived from ipamorelin. NN703 stimulates GH release from rat pituitary cells in a dose-dependent manner with a potency and efficacy similar to that of GHRP-6. The effect is inhibited by known GHS antagonists, but not by a GH-releasing hormone antagonist. Binding of (35)S-MK677 to the human type 1A GHS receptor (GHS-R 1A) stably expressed on BHK cells was inhibited by GHRP-6 and MK677 as expected. NN703 was also able to inhibit the binding of (35)S-MK677. However, the observed K(i) value was lower than expected, as based on the observed potencies regarding GH release from rat pituitary cells. Similarly, the effect of NN703 on the GHS-R 1A-induced inositol phosphate turnover in these cells showed a lower potency, when compared with GHRP-6 and MK677, than that observed in rat pituitary cells. The effect of i.v. administration of NN703 on GH and cortisol release was studied in swine. The potency and efficacy of NN703 on GH release were determined to be 155+/-23 nmol/kg and 91+/-7 ng GH/ml plasma respectively. A 50% increase of cortisol, compared with basal levels, was observed for all the tested doses of NN703, but no dose-dependency was shown. The effect of NN703 on GH release after i. v. and oral dosing in beagle dogs was studied. NN703 dose-dependently increased the GH release after oral administration. At the highest dose (20 micromol/kg), a 35-fold increase in peak GH concentration was observed (49.5+/-17.8 ng/ml, mean+/-s.e.m.). After a single i.v. dose of 1 micromol/kg the peak GH plasma concentration was elevated to 38.5+/-19.6 ng/ml (mean+/-s.e.m.) approximately 30 min after dosing and returned to basal level after 360 min. The oral bioavailability was 30%. The plasma half-life of NN703 was 4.1+/-0.4 h. A long-term biological effect of NN703 was demonstrated in a rat study, where the body weight gain was measured during a 14-day once daily oral challenge with 100 micromol/kg. The body weight gain was significantly increased after 14 days as compared with a vehicle-treated group. In summary, we here describe an orally active and GH specific secretagogue, NN703. This compound acts through a similar mechanism as GHRP-6, but has a different receptor pharmacology. NN703 induced GH release in both swine and dogs after i.v. and/or p.o. administration, had a high degree of GH specificity in swine and significantly increased the body weight gain in rats.

Studies on the glucocorticoid-receptor blocking action of RU 38486 in cultured ACTH-secreting human pituitary tumour cells and normal rat pituitary cells

1985 ◽  
Vol 109 (1) ◽  
pp. 64-69 ◽  
Author(s):  
S. W. J. Lamberts ◽  
E. G. Bons ◽  
P. Uitterlinden
Keyword(s):  
Pituitary Tumour ◽  
Tumour Cells ◽  
Pituitary Cells ◽  
Human Pituitary ◽  
Inhibiting Effect ◽  
Rat Pituitary ◽  
Normal Rat ◽  
Rat Pituitary Cells ◽  
Acth Secreting ◽  
Acth Release

Abstract. The glucocorticoid-receptor blocking actions of RU 38486, a new compound with anti-progesterone activity, have been investigated in cultured human ACTH-secreting pituitary tumour cells and normal rat pituitary cells. Pre-incubation of human pituitary tumour cells for 24 h with RU 38486 (1 μm) did not influence basal or CRF-stimulated ACTH release. RU 38486 (100 nm–1 μm) significantly overcame or prevented the dexamethasone (100 nm–1 μm)-induced inhibition of CRF-stimulated ACTH release by the cultured tumour cells prepared from 2 patients with Cushing's disease. The tumour cells of a third patient were insensitive to CRF. Pre-incubation for 24 h with 1 μm RU 38486 facilitated CRF-stimulated ACTH release significantly. Studies with cultured normal rat pituitary cells showed that the inhibiting effect of 24 h pre-incubation with 10 and 50 nm dexamethasone on CRF-stimulated ACTH release could be acutely (measured over 4 h) overruled in a dose-dependent way by RU 38486 (100 nm, 1 and 10 μ), while pre-incubation for 24 h of these cells with RU 38486 (100 nm and 1 μm) significantly attenuated the acute inhibiting effect of 1 μm dexamethasone on CRF-stimulated ACTH-release. The results of these in vitro experiments are discussed against the background of the possible therapeutic use RU 38486 in patients with Cushing's syndrome in order to block the deleterious effects of high circulating cortisol concentrations.

Effect of phorbol esters on the release of growth hormone and prolactin from rat pituitary cells cultured in monolayer

1984 ◽  
Vol 107 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Eiji Ohmura ◽  
Toshio Tsushima ◽  
Hitomi Murakami ◽  
Kae Wakai ◽  
Kazuo Shizume
Keyword(s):  
Growth Hormone ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Time Course ◽  
Phorbol Esters ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Cells Cultured

Abstract. The effect of phorbol diester tumour promoters on the release of growth hormone (GH) and prolactin (Prl) was studied in rat pituitary cells cultured in monolayer. 12-O-tetradecanoyl phorbol-13-acetate (TPA), the most potent phorbol ester, stimulated GH accumulation in the cultured medium in a dose-dependent manner. TPA also stimulated Prl accumulation. A time course study indicated that TPA mainly stimulates release of GH. The maximal stimulation of GH release by TPA (100 ng/ml) was 3–4-fold over control. Phorbol-12,13-dibutyrate (PDB), another tumour-promoting phorbol ester, stimulated GH release to an extent similar to that of TPA, while a biologically inactive compound, phorbol-12,13-diacetate (PDA), had no effect. TPA-stimulated GH release was not affected by the presence of indomethacin, an inhibitor of prostaglandin (PG) synthesis, indicating that PG is not involved in the process of TPA-stimulated GH release. Co++, a competitive antagonist of Ca++, at 2.0 mm completely suppressed the GH release induced by TPA, and this inhibition was partially reversed by the addition of 2.0 mm Ca++. Verapamil, a Ca++ channel blocker, reduced TPA-stimulated GH release, and trifluoperazine, an inhibitor of Ca-calmodulin formation, had a similar effect. Somatostatin (SRIF) also inhibited the GH release by TPA. These observations are compatible with the idea that Ca++ may be involved in the process of TPA-stimulated GH release. Since TPA has been reported to activate a Ca++- and phospholipiddependent protein kinase (protein kinase C), it is possible that TPA stimulate GH release by activating the enzyme. Further studies are required to clarify this point.

Site of inhibitory action of CRF 9-41 on ACTH release from isolated rat pituitary cells

Life Sciences ◽  
1987 ◽  
Vol 40 (12) ◽  
pp. 1179-1184 ◽  
Author(s):  
Mark J. Rosenthal ◽  
James C. Kraner ◽  
Glenn T. Peake
Keyword(s):  
Inhibitory Action ◽  
Pituitary Cells ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Isolated Rat ◽  
Acth Release

RAT MELANIN CONCENTRATING HORMONE DOES NOT MODIFY THE RELEASE OF CRH-41 FROM RAT HYPOTHALAMUS OR ACTH FROM THE ANTERIOR PITUITARY IN VITRO

1990 ◽  
Vol 127 (1) ◽  
pp. R1-R4 ◽  
Author(s):  
P. Navarra ◽  
S. Tsagarakis ◽  
D. H. Coy ◽  
L.H. Rees ◽  
G. M. Besser ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Anterior Pituitary ◽  
Pituitary Cells ◽  
Inhibitory Effects ◽  
Acth Secretion ◽  
Rat Pituitary ◽  
Melanin Concentrating Hormone ◽  
Rat Pituitary Cells ◽  
Acth Release

ABSTRACT It has been suggested that melanin concentrating hormone (MCH) possesses potent corticotrophin (ACTH) inhibitory activity, on the basis of the inhibitory effects displayed by salmon MCH on ACTH release from either trout or rat isolated pituitary fragments. Recently, rat MCH has been characterised, and this prompted us to investigate the putative inhibitory activity of synthetic rat MCH on basal and stimulated ACTH secretion from freshly-dispersed rat pituitary cells or incubated rat pituitary fragments, as well on KCl (28 mmol/l) or noradrenaline-evoked release of corticotrophin releasing hormone-41 (CRH-41) from rat hypothalamic explants in vitro. There were no effects of rat MCH on either CRH-41 or ACTH release in vitro.

A new clonal strain of rat pituitary tumour cells: a model for non-regulated secretion of prolactin

1984 ◽  
Vol 106 (4) ◽  
pp. 459-470 ◽  
Author(s):  
Marianne J. Reymond ◽  
D. Dale Nansel ◽  
G. Howard Burrows ◽  
William B. Neaves ◽  
John C. Porter
Keyword(s):  
Golgi Complex ◽  
Monolayer Culture ◽  
Pituitary Tumour ◽  
Pituitary Cells ◽  
Trace Quantity ◽  
Clonal Strain ◽  
Rat Pituitary ◽  
Dense Core Granules ◽  
Rat Pituitary Cells ◽  
Single Set

Abstract. A new clonal strain of Prl-secreting cells derived from the transplantable rat pituitary tumour. 7315a, has been established in culture. The cells of this strain, designed 235-1, have a highly developed Golgi complex, an extensive rough endoplasmic reticulum, and a few small but no large dense-core granules. When inoculated into athymic mice and rats of the Buffalo strain, the 235-1 cells produce tumours, and the host animals have hypertrophied mammary glands that produce milk, indicating that Prl secreted by these cells has mammotrophic activity. In monolayer culture, the doubling time of 235-1 cells is 31 ± 1 h (mean ± se). The cells secrete Prl, a trace quantity of GH, but no LH, FSH, TSH, ACTH, or α-MSH. Prl is released at a rate of 257 ± 12 fg per h per cell. The cellular content of Prl is 424 ± 23 fg per cell. Prl secretion by 235-1 cells is not affected by dopaminergic agonists and antagonists, TRH, or oestradiol-17β but is inhibited in the presence of EGTA or monensin, an ionophore that is believed to act at the level of the Golgi complex. The subcellular distribution of Prl in 235-1 cells is different from that in rat pituitary cells. In 235-1 cells, Prl is associated not with a single set of dense particles as it is in pituitary cells but with 2 sets of subcellular particles, of which co-et co-sedimented with particles having lysosomal enzyme activity. These findings suggest that Prl secretion by 235-1 cells involves secretory pathways that are different from those seen in normal lactotrophs.

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