scholarly journals Radioligand Binding Characteristics of the Endothelin Receptor in the Rabbit Iris

1998 ◽  
Vol 76 (3) ◽  
pp. 289-296 ◽  
Author(s):  
Chihiro Nosaka ◽  
Hitoshi Ishikawa ◽  
Isao Haruno ◽  
Takeshi Yoshitomi ◽  
Hiroshi Kase ◽  
...  
Keyword(s):  
Radioligand Binding ◽  
Endothelin Receptor ◽  
Binding Characteristics ◽  
Rabbit Iris

A high-affinity folate binding protein in human urine. Radioligand binding characteristics, immunological properties and molecular size

1989 ◽  
Vol 9 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Steen Ingemann Hansen ◽  
Jan Holm ◽  
Mimi Høier-Madsen
Keyword(s):  
Human Urine ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Molecular Size ◽  
Enzyme Linked Immunosorbent Assay ◽  
Folate Binding Protein ◽  
Binding Characteristics ◽  
High Affinity ◽  
Large Peak ◽  
Apparently Healthy

High-affinity binding of [3H]folate in human urine displayed characteristics, e.g. apparent positive cooperativity, which are typical of specific folate binding. By means of a two-site enzyme-linked immunosorbent assay (ELISA) with rabbit antibodies against the low molecular weight folate binding protein from human milk, we measured folate binding protein concentrations in the range of 0.51 to 4.13 nM in urine samples from 16 apparently healthy individuals. Ultrogel AcA 44 chromatography of the urine showed that immunoreactive and radioligand bound folate binding protein coeluted in one large peak (Mr∼25,000).

scholarly journals Pharmacological characterization of mutant huntingtin aggregate-directed PET imaging tracer candidates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Frank Herrmann ◽  
Manuela Hessmann ◽  
Sabine Schaertl ◽  
Karola Berg-Rosseburg ◽  
Christopher J Brown ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Trinucleotide Repeat ◽  
Radioligand Binding ◽  
Ex Vivo ◽  
Binding Assays ◽  
Pharmacological Characterization ◽  
Binding Characteristics

AbstractHuntington’s disease (HD) is caused by a CAG trinucleotide repeat expansion in the first exon of the huntingtin (HTT) gene coding for the huntingtin (HTT) protein. The misfolding and consequential aggregation of CAG-expanded mutant HTT (mHTT) underpin HD pathology. Our interest in the life cycle of HTT led us to consider the development of high-affinity small-molecule binders of HTT oligomerized/amyloid-containing species that could serve as either cellular and in vivo imaging tools or potential therapeutic agents. We recently reported the development of PET tracers CHDI-180 and CHDI-626 as suitable for imaging mHTT aggregates, and here we present an in-depth pharmacological investigation of their binding characteristics. We have implemented an array of in vitro and ex vivo radiometric binding assays using recombinant HTT, brain homogenate-derived HTT aggregates, and brain sections from mouse HD models and humans post-mortem to investigate binding affinities and selectivity against other pathological proteins from indications such as Alzheimer’s disease and spinocerebellar ataxia 1. Radioligand binding assays and autoradiography studies using brain homogenates and tissue sections from HD mouse models showed that CHDI-180 and CHDI-626 specifically bind mHTT aggregates that accumulate with age and disease progression. Finally, we characterized CHDI-180 and CHDI-626 regarding their off-target selectivity and binding affinity to beta amyloid plaques in brain sections and homogenates from Alzheimer’s disease patients.

scholarly journals Concentration, distribution, and influence of aging on the 18 kDa translocator protein in human brain: Implications for brain imaging studies

2019 ◽  
Vol 40 (5) ◽  
pp. 1061-1076 ◽  
Author(s):  
Junchao Tong ◽  
Belinda Williams ◽  
Pablo M. Rusjan ◽  
Romina Mizrahi ◽  
Jean-Jacques Lacapère ◽  
...  
Keyword(s):  
Human Brain ◽  
Protein Concentration ◽  
Radioligand Binding ◽  
Regional Distribution ◽  
Translocator Protein ◽  
Binding Characteristics ◽  
Protein Levels ◽  
Protein Pool ◽  
Positron Emission

Positron emission tomography (PET) imaging of the translocator protein (TSPO) is widely used as a biomarker of microglial activation. However, TSPO protein concentration in human brain has not been optimally quantified nor has its regional distribution been compared to TSPO binding. We determined TSPO protein concentration, change with age, and regional distribution by quantitative immunoblotting in autopsied human brain. Brain TSPO protein concentration (>0.1 ng/µg protein) was higher than those reported by in vitro binding assays by at least 2 to 70 fold. TSPO protein distributed widely in both gray and white matter regions, with distribution in major gray matter areas ranked generally similar to that of PET binding in second-generation radiotracer studies. TSPO protein concentration in frontal cortex was high at birth, declined precipitously during the first three months, and increased modestly during adulthood/senescence (10%/decade; vs. 30% for comparison astrocytic marker GFAP). As expected, TSPO protein levels were significantly increased (+114%) in degenerating putamen in multiple system atrophy, providing further circumstantial support for TSPO as a gliosis marker. Overall, findings show some similarities between TSPO protein and PET binding characteristics in the human brain but also suggest that part of the TSPO protein pool might be less available for radioligand binding.

Radioligand binding characteristics of β2–adrenoceptors of cultured melanoma cells

1990 ◽  
Vol 123 (2) ◽  
pp. 163-170 ◽  
Author(s):  
V. STEINKRAUS ◽  
MONIKA NOSE ◽  
H. MENSING ◽  
CHRISTA KORNER
Keyword(s):  
Radioligand Binding ◽  
Melanoma Cells ◽  
Binding Characteristics

Binding of yohimbine and imipramine to platelets in depressive illness

1986 ◽  
Vol 16 (4) ◽  
pp. 765-773 ◽  
Author(s):  
L. Braddock ◽  
P. J. Cowen ◽  
J. M. Elliott ◽  
S. Fraser ◽  
K. Stump
Keyword(s):  
Radioligand Binding ◽  
Antidepressant Treatment ◽  
Depressive Illness ◽  
Dexamethasone Suppression Test ◽  
Binding Characteristics ◽  
Imipramine Binding ◽  
Suppression Test ◽  
Severity Of Depression ◽  
Dexamethasone Suppression

SynopsisRadioligand binding to intact platelets was carried out in antidepressant-free patients and the 1 mg dexamethasone suppression test (DST) was performed. There were no differences in binding characteristics between patients and controls for either [H]yohimbine or [H]imipramine. There were no differences in binding between patients classified as endogenous using the Newcastle Scale, compared with non-endogenous patients, and no difference between DST suppressors and non-suppressors. The severity of depression did not affect binding values. After 4–6 weeks antidepressant treatment [H]yohimbine binding was significantly reduced but [H]imipramine binding was unaffected.

Differential Effects of a Novel Non-Peptide Endothelin Receptor Antagonist (Bosentan) in Rat Liver and Vasculature

1995 ◽  
Vol 89 (6) ◽  
pp. 575-579 ◽  
Author(s):  
Paddy A. Phillips ◽  
John Risvanis ◽  
Kathryn Aldred ◽  
Louise M. Burrell ◽  
Briony Bartholomeusz
Keyword(s):  
Receptor Antagonist ◽  
Time Course ◽  
Competitive Inhibition ◽  
Ex Vivo ◽  
Female Rat ◽  
Endothelin Receptor ◽  
Binding Characteristics ◽  
Orally Active

1. We studied the effects of the non-selective, non-peptide, orally active endothelin (ET) receptor antagonist bosentan (Ro 47–0203) on rat hepatic and mesenteric vascular membrane 125I-ET-1 binding characteristics in vitro and ex vivo (after bosentan by gavage in vivo). 2. Bosentan caused a concentration-dependent competitive inhibition of 125I-ET-1 binding to female rat mesenteric vascular (predominantly ETA receptors) and hepatic (predominantly ETB receptors) membranes in vitro and ex viva 3. The time course of the inhibition of binding ex vivo after administration of bosentan in vivo was 1–4 h for mesenteric vascular (predominantly ETA receptors) binding and 1–16 h for hepatic (predominantly ETB receptors) binding. 4. The time course of displacement of 125I-ET-1 binding from mesenteric vascular and hepatic membranes by bosentan in vitro was similar. 5. Since bosentan is significantly excreted by the liver, the prolonged hepatic 125I-ET-1 binding by bosentan presumably represents hepatic accumulation of bosentan, which may have implications for bosentan antagonizing the actions of ET in the liver.

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