کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5827142 1558919 2015 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Radiosynthesis and in vitro validation of 3H-NS14492 as a novel high affinity alpha7 nicotinic receptor radioligand
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب سلولی و مولکولی
پیش نمایش صفحه اول مقاله
Radiosynthesis and in vitro validation of 3H-NS14492 as a novel high affinity alpha7 nicotinic receptor radioligand
چکیده انگلیسی
The neuronal α7 nicotinic acetylcholine receptor is a homo-pentameric ligand-gated ion channel that is a promising drug target for cognitive deficits in Alzheimer׳s disease and schizophrenia. We have previously described 11C-NS14492 as a suitable agonist radioligand for in vivo positron emission tomography (PET) occupancy studies of the α7 nicotinic receptor in the pig brain. In order to investigate the utility of the same compound for in vitro studies, 3H-NS14492 was synthesized and its binding properties were characterized using in vitro autoradiography and homogenate binding assays in pig frontal cortex. 3H-NS14492 showed specific binding to α7 nicotinic receptors in autoradiography, revealing a dissociation constant (Kd) of 2.1±0.7 nM and a maximum number of binding sites (Bmax) of 15.7±2.0 fmol/mg tissue equivalent. Binding distribution was similar to that of another selective ligand 125I-α-bungarotoxin (125I-BTX) in autoradiography, and unlabeled NS14492 displaced 125I-BTX with an inhibition constant (Ki) of 23 nM. 3H-NS14492 bound to α7 nicotinic receptors in homogenized pig frontal cortex with a Kd of 0.8±0.3 nM and a Bmax of 30.2±11.6 fmol/mg protein. This binding assay further revealed the Ki rank order for a number of α7 nicotinic receptor agonists, and positive allosteric modulators (PAMs). Further, we saw increased binding of 3H-NS14492 to pig frontal cortex membranes when co-incubated with PNU-120596, a type II PAM. Taken together, these findings show that 3H-NS14492 is a useful new in vitro radioligand for the pig α7 nicotinic receptor.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Journal of Pharmacology - Volume 762, 5 September 2015, Pages 35-41
نویسندگان
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