Dose-dependent inhibition of growth hormone (GH)-releasing hormone- induced GH release by corticotropin-releasing hormone in prepubertal children

1996 ◽  
Vol 81 (4) ◽  
pp. 1397-1400 ◽  
Author(s):  
L. Ghizzoni
Keyword(s):  
Growth Hormone ◽  
Corticotropin Releasing Hormone ◽  
Prepubertal Children ◽  
Releasing Hormone ◽  
Inhibition Of Growth ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Targeted, Dose-Dependent Inhibition of Growth Hormone Secretion by the Botulinum Neurotoxin-Based TSI SXN101000 and SXN101742

2011 ◽  
pp. P2-332-P2-332
Author(s):  
James Daniel Leggett ◽  
Eleanor Jane Waite ◽  
Philip Michael Hunt Marks ◽  
Alberto Martinez ◽  
Stafford Louis Lightman
Keyword(s):  
Growth Hormone ◽  
Botulinum Neurotoxin ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Inhibition Of Growth ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

scholarly journals In vitro impact of pegvisomant on growth hormone-secreting pituitary adenoma cells

2016 ◽  
Vol 23 (7) ◽  
pp. 509-519 ◽  
Author(s):  
Thomas Cuny ◽  
Caroline Zeiller ◽  
Martin Bidlingmaier ◽  
Céline Défilles ◽  
Catherine Roche ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cell Line ◽  
Primary Cultures ◽  
Somatostatin Analogs ◽  
Primary Tumors ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
The Impact ◽  
Dose Dependent

Pegvisomant (PEG), an antagonist of growth hormone (GH)-receptor (GHR), normalizes insulin-like growth factor 1 (IGF1) oversecretion in most acromegalic patients unresponsive to somatostatin analogs (SSAs) and/or uncontrolled by transsphenoidal surgery. The residual GH-secreting tumor is therefore exposed to the action of circulating PEG. However, the biological effect of PEG at the pituitary level remains unknown. To assess the impact of PEG in vitro on the hormonal secretion (GH and prolactin (PRL)), proliferation and cellular viability of eight human GH-secreting tumors in primary cultures and of the rat somatolactotroph cell line GH4C1. We found that the mRNA expression levels of GHR were characterized in 31 human GH-secreting adenomas (0.086 copy/copy β-Gus) and the GHR was identified by immunocytochemistry staining. In 5/8 adenomas, a dose-dependent inhibition of GH secretion was observed under PEG with a maximum of 38.2±17% at 1μg/mL (P<0.0001 vs control). A dose-dependent inhibition of PRL secretion occurred in three mixed GH/PRL adenomas under PEG with a maximum of 52.8±11.5% at 10μg/mL (P<0.0001 vs control). No impact on proliferation of either human primary tumors or GH4C1 cell line was observed. We conclude that PEG inhibits the secretion of GH and PRL in primary cultures of human GH(/PRL)-secreting pituitary adenomas without effect on cell viability or cell proliferation.

Corticotropin-Releasing Hormone Inhibition of Growth Hormone-Releasing Hormone-Induced Growth Hormone Release in Man*

1990 ◽  
Vol 71 (5) ◽  
pp. 1368-1374 ◽  
Author(s):  
ANTONINO BARBARINO ◽  
SALVATORE M. CORSELLO ◽  
SILVIA DELLA CASA ◽  
ANNA TOFANI ◽  
ROSA SCIUTO ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Growth Hormone Releasing Hormone ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Inhibition Of Growth

Dose-Dependent Inhibition of Pituitary-Ovarian Function during Administration of a Gonadotropin-Releasing Hormone Agonistic Analog (Nafarelin)*

1986 ◽  
Vol 63 (6) ◽  
pp. 1334-1341 ◽  
Author(s):  
SCOTT E. MONROE ◽  
ZEEV BLUMENFELD ◽  
JANICE L. ANDERYKO ◽  
ELDON SCHRIOCK ◽  
MILAN R. HENZL ◽  
...  
Keyword(s):  
Ovarian Function ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Corticotrophin-releasing hormone (CRH)-binding protein interference with CRH antibody binding: implications for direct CRH immunoassay

1995 ◽  
Vol 146 (1) ◽  
pp. 45-53 ◽  
Author(s):  
E A Linton ◽  
A V Perkins ◽  
P Hagan ◽  
S Poole ◽  
A F Bristow ◽  
...  
Keyword(s):  
Human Plasma ◽  
Binding Protein ◽  
Releasing Hormone ◽  
Standard Curve ◽  
Direct Immunoassay ◽  
Dependent Inhibition ◽  
Normal Human ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Dilution Curves

Abstract Direct immunoassay of plasma corticotrophin-releasing hormone (CRH) is potentially subject to interference from high levels of CRH-binding protein (CRH-BP) that exist in the human circulation. In this study, we tested the effect of CRH-free, native CRH-BP (6·4 nmol/l) purified from human plasma, CRH-BP diluent alone, normal human plasma (containing 5·8 nmol endogenous CRH-BP/1) and normal sheep plasma (containing no CRH-BP) on the binding of 125I-labelled CRH tracer to five N-terminal and four C-terminal CRH antibodies. All anti-(1–20)CRH N-terminal antibody dilution curves displayed marked inhibition of binding in the presence of purified CRH-BP and human plasma in comparison with the curves with the control diluent or sheep plasma. Almost no inhibition of binding was obtained with any of the C-terminal antibodies (all directed against epitopes within the last six amino acids of CRH) and the four dilution curves were nearly superimposable. Liquid-phase CRH IRMAs were then developed with different combinations of two of each of the N- and C-terminal antibodies, using radiolabelled IgG prepared from purified C-terminal antisera as tracer and raw N-terminal antisera as the link antibodies to the separating system. The addition of dilutions of purified CRH-BP over the range 1·25–20 nmol/l to the IRMA standard curve in assay buffer resulted in a dose-dependent reduction in the signal; with 5 nmol CRH-BP/1, a level commonly found in human plasma, the reduction in binding was 67% and 81% in two different IRMAs at a CRH concentration of 631 pmol/l. With endogenous CRH-BP in human plasma, a dose-dependent inhibition of binding similarly resulted, with the plasma containing the most CRH-BP causing the greatest inhibition. Since plasma CRH-BP levels in humans vary widely, direct plasma IRMA using these type of antibodies will give inaccurate results and initial extraction of the CRH is necessary. Methanol extraction of synthetic or endogenous CRH is shown to be both highly efficient and unaffected by variable amounts of endogenous or exogenous CRH-BP; it is therefore suitable as the first step in plasma CRH measurement by IRMA. Journal of Endocrinology (1995) 146, 45–53

Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽  
2000 ◽  
pp. 15-23 ◽  
Author(s):  
K Jewgenow ◽  
M Rohleder ◽  
I Wegner
Keyword(s):  
In Vitro Fertilization ◽  
Zona Pellucida ◽  
Antigenic Determinants ◽  
Vitro Fertilization ◽  
Contraceptive Vaccine ◽  
Sperm Binding ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

Antioxidant effects and in vitro cytotoxicity on human cancer cell lines of flavonoid-rich Flamboyant (Delonix regia (Bojer) Raf.) flower extract

2020 ◽  
Vol 21 ◽  
Author(s):  
Putthiporn Khongkaew ◽  
Phanphen Wattanaarsakit ◽  
Konstantinos I. Papadopoulos ◽  
Watcharaphong Chaemsawang
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Flower Extract ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Murine Leukemia Cell ◽  
Dose Dependent

Background: Cancer is a noncommunicable disease with increasing incidence and mortality rates both worldwide and in Thailand. Its apparent lack of effective treatments is posing challenging public health issues. Introduction: Encouraging research results indicating probable anti-cancer properties of the Delonix regia flower extract (DRE) have prompted us to evaluate the feasibility of developing a type of product for future cancer prevention or treatment. Methods and Results: In the present report, using High Performance Liquid Chromatography (HPLC), we demonstrate in the DRE, the presence of high concentrations of three identifiable flavonoids, namely rutin 4.15±0.30 % w/w, isoquercitrin 3.04±0.02 %w/w, and myricetin 2.61±0.01 % w/w respectively while the IC50 of DPPH and ABTS assay antioxidation activity was 66.88±6.30 µg/ml and 53.65±7.24 µg/ml respectively. Discussion: Our cancer cell line studies using the MTT assay demonstrated DREs potent and dose dependent inhibition of murine leukemia cell line (P-388: 35.28±4.07% of cell viability remaining), as well as of human breast adenocarcinoma (MCF-7), human cervical carcinoma (HeLa), human oral cavity carcinoma (KB), and human colon carcinoma (HT-29) cell lines in that order of magnitude. Conclusion: Three identifiable flavonoids (rutin, isoquercitrin and myricetin) with high antioxidation activity and potent and dose dependent inhibition of murine leukemia cell line and five other cancer cell lines were documented in the DRE. The extract’s lack of cytotoxicity in 3 normal cell lines is a rare advantage not usually seen in current antineoplastic agents. Yet another challenge of the DRE was its low dissolution rate and long-term storage stability, issues to be resolved before a future product can be formulated.

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