NPS 2143 causes a brief rise in plasma Ca2+ levels in rats as well as a fast 4- to 5-fold increase in plasma PTH levels. When administered intraperitoneally (i.v.) at a dose of 1 mg/kg, NPS 2143 significantly raises mean arterial blood pressure (MAP) in rats with normotension who also have parathyroid glands.

The HEK 293 4.0-7 clonal cell line is utilized in a high-throughput screening format to identify Ca2+ receptor agonists and allosteric activators. A quantitative and functional evaluation of the Ca2+ receptor activity in these cells can be obtained by measuring changes in the concentration of cytoplasmic [Ca2+]i. The outcomes of this assay are comparable to those obtained using a homologous expression system of bovine parathyroid cells. Using a fluorescence imaging plate reader or a specially designed spectrofluorimeter, HEK 293 4.0-7 cells loaded with either fura-2 or fluo-3 can have their fluorescence measured continuously and online. Extracellular Ca2+ concentration is raised from 1.0 mM to 1.75 mM after NPS-2143 is incubated with cells for one minute. Bioactive NPS-2143 is defined as those that cause more than 40% inhibition of the control response when tested individually at concentrations of 100 μg/mL (20 μM-80 μM). The effects of NPS-2143 on [Ca2+]i evoked by other G protein-coupled receptors are then investigated at a concentration several times their IC50 as an initial assessment of selectivity. Concentration-response curves are obtained to determine the potencies (IC50) of NPS-2143 with biological activity. The activation of intracellular Ca2+ is correlated with the expression of thrombin, bradykinin, and ATP receptors in wild-type HEK 293 cells as well as HEK 293 4.0-7 cells. To evaluate a compound's nonselective action on G protein-coupled receptors quickly, these responses can be examined. Other assays for selectivity involve using HEK 293 cells that have been modified to express receptors that are most similar to the Ca2+ receptor in terms of topology and sequence. These comprise GABABRs (gamma-aminobutyric acid type B) and various metabotropic glutamate receptors, either native or chimeric. In order to couple to the activation of phospholipase C and the release of intracellular Ca2+ in HEK 293 cells, chimeric receptors are synthesized using partial sequences of metabotropic glutamate receptors and Ca2+ receptors. In an iterative process, NPS-2143 lacking pan-activity are then exposed to structural modifications, and their potencies and selectivities are tracked using these HEK 293 4.0-7 cell assays.

Calcilytics NPS-2143 has been shown to reduce the CaSR's sensitivity to [Ca2+]o, which attenuates signal transduction in vitro and increases PTH secretion in vivo. Furthermore, for the wild-type CaSR and mutant CaSR (T151R, P221L, E767Q, G830S, and A844T), respectively, the EC50 values of NPS-2143 are 4.27, 1.56, 1.61, 2.46, 2.07, and 3.15 mM. In addition to this, it has been shown that NPS-2143 inhibits the [Ca2+]o-induced cytosolic calcium signal in HEK 293T cells expressing CaSR in a concentration-dependent way.

[1]. Calcilytic compounds: potent and selective Ca2+ receptor antagonists that stimulate secretion of parathyroid hormone. J Pharmacol Exp Ther. 2001 Oct;299(1):323-31.

[2]. Hypertensive effect of calcilytic NPS 2143 administration in rats. J Endocrinol. 2006 Oct;191(1):189-95.

[3]. Involvement of the calcium-sensing receptor in human taste perception. J Biol Chem. 2010 Jan 8;285(2):1016-22.

[4]. Calcium-sensing receptor mediates dietary peptide-induced CCK secretion in enteroendocrine STC-1 cells. Mol Nutr Food Res. 2012 May;56(5):753-60.

[5]. Calcium-sensing receptor: a sensor and mediator of ischemic preconditioning in the heart. Am J Physiol Heart Circ Physiol. 2010 Nov;299(5):H1309-17.

C24H26CL2N2O2

445.38144

444.14

C, 64.72; H, 5.88; Cl, 15.92; N, 6.29; O, 7.18

324523-20-8

NPS-2143; 284035-33-2

Solid powder

CC(C)(CC1=CC2=CC=CC=C2C=C1)NC[C@H](COC3=C(C(=CC=C3)Cl)C#N)O.Cl

ZEBNDUQLNGYBNL-VEIFNGETSA-N

InChI=1S/C24H25ClN2O2.ClH/c1-24(2,13-17-10-11-18-6-3-4-7-19(18)12-17)27-15-20(28)16-29-23-9-5-8-22(25)21(23)14-26;/h3-12,20,27-28H,13,15-16H2,1-2H3;1H/t20-;/m1./s1

2-chloro-6-[(2R)-2-hydroxy-3-[(2-methyl-1-naphthalen-2-ylpropan-2-yl)amino]propoxy]benzonitrile;hydrochloride

SB262470; SB-262470; SB 262470; SB-262470A; NPS2143; NPS-2143; NPS 2143

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: ≥ 100 mg/mL (~224.5 mM)
H2O: ~1.9 mg/mL (~4.2 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.61 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.61 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.61 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)