AM095 

Known amounts of AM095 (diluted in DMSO) or vehicle (DMSO) are added to 25 to 40 μg of hLPA₁/CHO or mLPA₁/CHO membranes and 0.1 nM [³⁵S]-GTPγS in buffer (50 mM HEPES, 0.1 mM NaCl, 10 mM MgCl₂, 50 μg/mL saponin, pH 7.5) containing 0.2% fatty acid-free human serum albumin and 5 μM GDP. To test for LPA₁ antagonist activity, the ability of AM095 to inhibit GTPγS binding stimulated by 900 nM LPA (18:1) is measured. Alternatively, to test for agonist effects, the ability of AM095 to stimulate GTPγS binding in the absence of LPA is measured. Reactions are incubated for 30 min at 30°C, before harvesting membranes onto glass filter binding plates (UniFilter GF/B) and washing three times with cold buffer containing 50 mM HEPES, pH 7.4, 100 mM NaCl, 10 mM MgCl₂ using a Brandel 96-tip cell harvester. Plates are dried and then cpm are evaluated by using a Packard TopCount NXT microplate scintillation counter^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Rats^[1]
Male Sprague-Dawley rats with surgically implanted jugular vein catheters (250-300 g) are used. In all studies, animals are fasted 15 to 24 h before dosing. For rats, AM095 is administered intraveneously at a dose of 2 mg/kg in 0.9% saline given as a 1 mL/kg bolus injection into the jugular vein. To determine oral exposure, AM095 is administered as a solution in 0.5% methylcellulose via an oral gavage at a dose of 10 mg/kg in a volume of 3 mL/kg. Blood samples (approximately 300 μL of total blood) are taken from each rat via the jugular vein catheter at times up to 24 h postdose (10-11 samples per animal) in potassium EDTA tubes. After each sampling, the catheter is flushed with an equivalent volume of saline. Plasma samples, prepared by centrifugation of whole blood, are stored frozen (−80°C) before analysis. AM095 is dosed intravenously at 2 mg/kg and orally at 5 mg/kg to male beagle dogs (n=3). Plasma samples are collected and analyzed for AM095 concentration by liquid chromatography/mass spectrometry.
Mice^[2]
C57Bl/6 mice are administered the selective LPA₁ antagonist AM095 by oral gavage (30 mg/kg) at time 0 and 8 h, and blood is collected by cardiac puncture under anesthesia in sodium EDTA tubes at 0, 4, 8, 9, 12 and 24 h. Plasma samples are stored at −40°C prior to analysis of AM095 concentrations by liquid chromatography/mass spectrometry (LC-MS/MS). Known amounts of AM095 are added to thawed mouse plasma to yield a concentration range from 0.8 to 4,000 ng/mL. Plasma samples are precipitated using acetonitrile containing the internal standard buspirone. The analyte mixture (10 μL) is injected using a Leap PAL autosampler. Calibration curves are constructed by plotting the peak-area ratio of analyzed peaks against known concentrations. The lower limit of quantitation is 1 ng/mL. The data are subjected to linear regression analysis with 1/x² weighting. The pharmacokinetic parameters of AM095 are calculated by non-compartmental analysis using WinNonlin Professional. C_max and time to C_max (T_max) are obtained directly from the measured data.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Swaney JS, et al. Pharmacokinetic and pharmacodynamic characterization of an oral lysophosphatidic acid type 1 receptor-selective antagonist. J Pharmacol Exp Ther. 2011 Mar;336(3):693-700.  [Content Brief]

  [2]. Castelino FV, et al. Amelioration of dermal fibrosis by genetic deletion or pharmacologic antagonism of lysophosphatidic acid receptor 1 in a mouse model of scleroderma. Arthritis Rheum. 2011 May;63(5):1405-15.  [Content Brief]