Rat H3 receptor (pKi = 8.9); human H3 receptor (pKi = 9.24)

In vitro characterization of JNJ-5207852 [1]
The structure of JNJ-5207852 (1-[4-(3-piperidin-1-yl-propoxy)-benzyl]-piperidine) is shown in Figure 1. In radioligand-binding assays, JNJ-5207852 shows high affinity for both the human and rat H3 receptor with pKi values of 9.24±0.21 and 8.90±0.17, respectively (average±s.d. of at least two triplicates). The corresponding values for the reference antagonist, thioperamide, were 7.40±0.33 and 8.40±0.20, respectively. Thus, JNJ-5207852 had three- and 100-fold higher affinities for the rat and human receptor compared to the reference compound. The functional cell-based assay for antagonist potency measured the ability of the compound to cause a rightward shift in the concentration–response curves of histamine-mediated inhibition of forskolin-induced cAMP accumulation. The results show good concordance with the pKi values obtained in binding experiments, with pA2 values of 8.94 and 9.84 at the rat H3 and human H3 receptor. Slopes of Schild regression analysis were not significantly different from unity.
Constitutive activity has been described for the H3 receptor (Wieland et al., 2001), opening up the possibility that some compounds might function as inverse agonists. However, in our functional assays, we were not able to detect consistent and pronounced constitutive activity of the H3 receptor, which made it difficult to evaluate neutral antagonism or inverse agonism directly. Instead, we utilized a variant of the binding assay, where Ki values were determined in the presence or absence of GppNHp and high concentrations of NaCl. JNJ-5207852 and the reference agonist imetit and the reference inverse agonist thioperamide were evaluated. Imetit, as expected, showed a Ki ratio of <1 (0.47±0.11), while thioperamide had a ratio of >1 (3.39±0.50). JNJ-5207852 had a Ki ratio close to 1 (1.25±0.16), which is indicative of neutral antagonism.
JNJ-5207852 did not bind to human H1, H2 or H4 histamine receptors (pKi <5 for all), despite the significant sequence homology between the H3 and H4 receptors. Thioperamide, in contrast, had a pKi of 7.1 at the human H4 receptor. JNJ-5207852 was also tested in a commercial (CEREP, Rueil-Malmaison, France) battery of approximately 50 G-protein-coupled receptors, ion channels and other drug targets. At a concentration of 1 μM, the compound had no inhibitory effect greater than 50% at any of these targets.

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In vitro autoradiography [1]
JNJ-5207852 was radiolabeled with tritium (3H-JNJ-5207852); so we could assess the direct binding interactions with the H3 receptor. Scatchard analysis of experiments with 3H-JNJ-5207852 yielded pKd values of 8.69 and 8.84 at the human receptor and rat receptor, respectively (Figure 2a and not shown). To further confirm the specificity of the binding, in vitro autoradiography with 3H-JNJ-5207852 was performed on brain slices from wild-type or H3 receptor knockout (H3−/−) mice. The high-affinity H3 receptor agonist 3H-N-α-methylhistamine was evaluated as a reference. Neither 3H-N-α-methylhistamine (not shown) nor 3H-JNJ-5207852 showed any appreciable binding in the brains of H3 receptor-deficient mice, whereas the wild-type mice showed a normal patttern of H3 receptor binding with 3H-JNJ-5207852, with extensive labeling in the cortex, hypothalamus and striatum (Figure 2b).

In H3 receptor knockout mice, JNJ-5207852 (1–10 mg/kg sc) has no effect on wakefulness or sleep, but it enhances wakefulness and decreases REM and slow-wave sleep. H3 receptor antagonists arouse people without the need for strenuous activity. For four weeks, JNJ-5207852 (10 mg/kg ip) administered daily to mice did not cause any changes in body weight. After oral treatment, JNJ-5207852 is well absorbed and reaches high brain levels [1].

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Ex vivo autordiography [1]
In order to evaluate whether JNJ-5207852 would be a suitable tool to study central H3 receptor function in vivo, we performed ex vivo autoradiography to measure receptor occupancy after peripheral administration of unlabeled compound. Ex vivo brain autoradiography was performed after s.c. administration of 0.04–2.5 mg kg−1 of JNJ-5207852. The results indicated that JNJ-5207852 penetrates rapidly into the brain and achieves good receptor occupancy, as measured by the competition for 3H-N-α-methylhistamine-binding sites. The ED50 for receptor occupancy 1 h after dosing was 0.13 mg kg−1, compared to 2 mg kg−1 for thioperamide (Figure 3).

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Provigilant effects of JNJ-5207852 in rats [1]
Based on the receptor occupancy data, doses of 1 and 10 mg kg−1 JNJ-5207852 would be expected to elicit pharmacological effects. These two doses of JNJ-5207852 (1 and 10 mg kg−1) or vehicle were administered s.c. to rats. The animals' various sleep stages were monitored for two intervals of 30 min prior to, and three intervals of 30 min after administration of vehicle or test compound. JNJ-5207852 elicited a dose-dependent increase in the total time spent awake (Figure 4a). This wake-promoting effect was most noticeable at the higher dose, where 10 mg kg−1 JNJ-5207852 caused an increase in time spent awake that manifested within the first 30 min after dosing and remained present throughout the observation period (1580±103 vs 640±122 s in the vehicle-treated animals in the 30–60 min post-dosing interval, P<0.05; 1525±241 vs 577±184 s in the vehicle-treated animals in the 60–90 min post-dosing observation interval, P<0.05). At 1 mg kg−1, a trend for increased waking in treated vs vehicle animals was apparent, which did not reach statistical significance.
The increase in waking was accompanied by significant decreases in the amount of time spent in SWS, as shown in Figure 4b (e.g. for the 60–90 min observation interval: 253±219 s in rats treated with 10 mg kg−1 JNJ-5207852 vs 1026±189 s in vehicle-treated rats, P<0.05). REM sleep was likewise decreased, although the difference did not reach statistical significance (Figure 4e). The increase in waking was apparent both as quiet and active waking (Figure 4c, d).

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Sleep–wake effects of JNJ-5207852 in wild-type and H3 receptor knockout mice [1]
The effects of JNJ-5207852 (10 mg kg−1) on sleep/wake were measured following s.c. injections in H3+/+ (n=6) and H3−/− (n=6) mice at light onset. Administration of JNJ-5207852 (10 mg kg−1) to H3+/+ mice significantly increased wakefulness (P<0.03, treatment × time), in hours 1–2 (+143%, P<0.01), hours 7–8 (+153%, P<0.001), hours 11–12 (+118%, P<0.05) and hours 22–24 (+125%, P<0.01) compared to the vehicle condition (Figure 5, top panel). Consequently, the amount of 24-h accumulated wakefulness was greater following JNJ-5207852 administration (P<0.001). The increase in wakefulness was accompanied by decreased SWS during corresponding time intervals (P<0.04, treatment × time), leading to an overall 24-h reduction in SWS (P<0.001) (Figure 5, middle panel). REM was nonsignificantly attenuated during the same times that SWS was decreased (data not shown). Similarly, JNJ-5207852 reduced total slow-wave delta power (P<0.05), with significant effects during particular 2-h intervals (P<0.001, treatment × time), as shown in Figure 5, bottom panel.
The structure of sleep–wake cycles was also affected in H3+/+ mice by JNJ-5207852, as evidenced by time-dependent increases in the number of stage shifts (P<0.001), wake bouts (P<0.001) and SWS bouts (P<0.001) (Figure 6, top panels). The duration (min) of individual bouts was decreased for wakefulness (P<0.001, treatment × time) and SWS (P<0.001, treatment effect) (Figure 6, bottom panels). In combination, these measures indicate that, in H3+/+ mice, JNJ-5207853 significantly increased wake time and decreased the continuity of the sleep–wake cycle.
In contrast, the H3−/− mice were insensitive to the wake-promoting effect of 10 mg kg−1 JNJ-5207852 and sleep–wake amounts were comparable to the vehicle condition (Figure 5). Sleep latencies for slow-wave and REM sleep were not affected by JNJ-5207852 in either H3+/+ or H3−/− mice. Mean body temperature during the post-injection period was similar regardless of genotype or injection condition (data not shown).

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Absence of locomotor stimulant effects of JNJ-5207852 in rats [1]
In order to differentiate the wake-promoting effects of JNJ-5207852 from other classes of stimulants, we tested the effect of JNJ-5207852 on locomotor activity. Animals were injected s.c. with 3, 10, or 30 mg kg−1 JNJ-5207852 and observed for 4 h. A separate group of animals received 0.75 mg kg−1 D-amphetamine s.c. Figure 7 shows the locomotor activity for the first 90 min after administration. This observation period was chosen to mirror the studies of the effect of JNJ-5207852 on the rat EEG, which ran over three consecutive periods of 30 min. As shown in Figure 7, amphetamine induced a clear increase in locomotion within the first 90 min after injection. In contrast, JNJ-5207852, at doses up to 30 mg kg−1 (s.c.), was devoid of locomotor stimulant effects. Fine movements and rearing were likewise unchanged in the animals treated with JNJ-5207852, indicating the absence of stereotypy. The results were identical when the same doses were administered i.p. (not shown).

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Lack of effect of JNJ-5207852 on body weight in control and ob/ob mice [1]
Control and ob/ob mice received daily i.p. injections of saline, 3 or 10 mg kg−1 JNJ-5207852, and their body weights were measured daily for 28 days. The ob/ob mice displayed the rapid increase in body weight that is typical for this mutant strain with a starting body weight of 40.4±1.6 g to an end of study body weight of 52.2±1.0 g. Treatment of ob/ob mice with JNJ-5207852 did not affect the increase in body weight over time. The ob/ob mice treated with 3 mg kg−1 JNJ-5207852 started the study with a body weight of 41.7±2.4 g and ended it with a body weight of 51.5±1.1 g. The group receiving 10 mg kg−1 i.p. daily went from 40.5±0.7 g at the start of the study to 51.9±1.1 g after 28 days. The control mice treated with vehicle gained weight at a more moderate pace (from 23.0±0.6 to 27.1±0.6 g). The control mice treated with 10 mg kg−1 JNJ-5207852 started out at 22.9±0.8 g and ended the study at 28.4±0.9 g. Daily inspection of the JNJ-5207852-treated mice did not reveal any gross changes in general health or behavior.

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The role of the histamine H(3) receptor (H(3)R) in anxiety is controversial, due to limitations in drug selectivity and limited validity of behavioral tests used in previous studies. In the present report, we describe two experiments. In the first one, Wistar rats were treated with an H(3)R agonist (methimepip), and exposed to an open-field. In the second one, Balb/c mice were treated with H(3)R agonist (methimepip) or antagonist (JNJ-5207852), and exposed to an open space 3D maze which is a modified version of the radial-arm maze. C57BL/6J saline treated mice were included for comparisons. When exposed to an empty open field, Wistar rats spent more time in the outer area and made very low number of brief crossings in the central area. However, when an object occupied the central area, rats crossed frequently into and spent a long time in the central area. Administration of a range of different doses of methimepip (selective H(3)R agonist) reduced the entries into the central area with a novel object, indicating enhanced avoidance response. In the 3D maze, both Balb/c and C57BL/6J saline-treated mice crossed frequently onto the bridges that radiate from the central platform but only C57BL/6J mice crossed onto the arms which extend the bridges. This suggests that Balb/c mice are more anxious than C57BL/6J mice. Neither methimepip nor JNJ-5207852 (selective H(3)R antagonist/inverse agonist) induced entry into the arms of the maze, indicative of lack of anxiolytic effects. [2]

H3 receptor binding [1]
Binding of compounds to the cloned human and rat H3 receptor, stably expressed in SK-N-MC cells, was performed as described earlier (Lovenberg et al., 2000). IC50 values were determined by a single-site curve-fitting program and converted to Ki values based on a N-[3H]-α-methylhistamine Kd of 800 pM and a ligand concentration of 800 pM (Cheng & Prusoff, 1973).
For the experiments to determine inverse agonism/neutral antagonism of the compounds, Ki determinations were performed in the presence or absence of 25 μM 5′-guanylylimidodiphosphate (GppNHp) and 100 mM NaCl (Martin et al., 2002).
3H-JNJ-5207852 (20–30 Ci mmol−1) was prepared through a contract with Sibtech. Saturation-binding experiments were performed at concentrations of radioactive ligand between 0.5 and 65 nM. Nonspecific binding was determined in the presence of 10 μM histamine.

Animal/Disease Models: Male, SD (SD (Sprague-Dawley)) rat, weight 282-334 grams [1].
Doses: 3, 10, 30 mg/kg.
Route of Administration: SC
Experimental Results: Increased wakefulness and diminished REM and slow wave sleep.

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JNJ-5207852 and D-amphetamine were freshly prepared and dissolved in sterile physiological saline. All compounds were administered s.c. or i.p. and all drug dosages refer to the compound salts. For the in vivo pharmacology studies, JNJ-5207852 was used as a hydrochloride salt, except for the locomotor studies, where the fumarate salt was used . For the pharmacokinetics studies, the fumarate salt was also used and a salt correction factor was applied.

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Effect of JNJ-5207852 on sleep and waking in rats [1]
All animal work reported in this paper was performed in accordance with the Declaration of Helsinki.

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Animals and surgery [1]
Male Sprague–Dawley rats weighing 280–350 g were used in all studies. Stereotaxic surgery was performed using halothane anaesthesia administered through a nose cone, with the incisor bar set at 11.5 mm below ear bar zero, and body temperature was maintained at approximately 36°C. Animals were housed in pairs prior to and following surgery. The post-surgical recovery time was 5–7 days.Electroencephalography and electromyography (EEG and EMG) electrodes were implanted as described below. EEG/EMG electrodes were cemented in position with acrylic cement. Animals were maintained on a 11 : 13 h cycle, with lights on at 06:00 h. On the day of testing, animals were connected to an EEG/EMG recording FET headstage. Following the return to a resting state, testing was initiated. Testing was conducted between 10:00 and 15:00 h. Following 60 min of collection of baseline data, animals were injected subcutaneously (s.c.) with vehicle, 1.0 or 10.0 mg kg−1 JNJ-5207852. Recording of behavior and EEG/EMG data was continued for the subsequent 90 min. Each animal was tested with both doses of JNJ-5207852. Testing sessions were separated by 3–4 days. All compounds were dissolved in artificial extracellular fluid (147 mM NaCl, 1.3 mM CaCl2, 0.9 mM MgCl2, 2.5 mM KCl, 5.0 mM NaH2P04, pH 7.4).

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Effect of JNJ-5207852 on sleep-waking and body temperature in mice lacking the H3 receptor [1]
Electrode and transducer implantation [1]
At 3 months of age, H3+/+ (n=6) and H3−/− (n=6) male (24–34 g) mice were surgically implanted with chronic electrodes for EEG/EMG recording as described previously (Toyota et al., 2002). In addition, transducers (PDT-4000 E-Mitter, Mini-Mitter) were inserted in the peritoneal cavity for biotelemetric recording of body temperature. Following surgery, mice were individually housed and given 2 weeks to recover from the procedure.

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Challenge with JNJ-5207852 [1]
Mice were connected to a cable/rotating swivel system for EEG/EMG recording and allowed 1 week of adaptation to a sleep-recording chamber. The recording environment was temperature (23–24°C) and light (12L : 12D) controlled, with food and water available ad libitum. Each mouse was injected 1 day with saline (4 ml kg−1 body weight) and the next day with 10 mg kg−1 of JNJ-5207852 (dissolved in saline), followed by 24-h of EEG/EMG recording. Injections were made s.c. and performed at the onset of the circadian light phase (08:00 h). EEG/EMG signals were fed into amplifiers, filtered (0.3–50 Hz bandpass), and then digitized and stored on an on-line computer data acquisition program.

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Ex vivo autoradiography for determination of receptor occupancy [1]
Male Wistar rats (200 g) were treated by s.c. administration of vehicle or JNJ-5207852 at four dosages ranging from 0.16 to 2.5 mg kg−1 body weight (dosages: 0.16, 0.63, 2.5; three animals per dose). Thioperamide was administered at doses from 0.16 to 10 mg kg−1 (0.16, 0.63, 2.5, 10). The animals were decapitated 1 h after compound administration. Brains were immediately removed from the skull and rapidly frozen in dry-ice-cooled 2-methylbutane (−40°C). Sections (20 μm thick) were cut using a Leica CM 3050 cryostat-microtome, and thaw-mounted on microscope slides. The sections were then kept at −20°C until use.
Occupancy of H3 receptors was measured in the striatum of each individual rat. After thawing, the sections were dried under a stream of cold air and then incubated at RT for 10 min in 50 mM Na/K phosphate buffer (pH 7.4) containing 2 nM [3H]-R-α-methylhistamine. Nonspecific binding was measured on adjacent sections in the presence of 1 μM clobenpropit. After the incubation, the slides were washed (4 × 20 s) in ice-cold buffer, followed by a quick rinse in ice-cold water. The sections were then dried under a stream of cold air.
Quantitative autoradiography analysis was performed after 1 h acquisition with the β-imager according to our standard protocol (Langlois et al., 2001). The ED50 values (dose of compound producing 50% of H3 receptor occupancy) were calculated by nonlinear regression analysis, using the GraphPad Prism program.

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Effect of JNJ-5207852 on body weight in control and ob/ob mice [1]
Male mice (C57BL/6 and ob/ob) were obtained from Jackson Labs and individually housed with a 12L : 12D photoperiod. They had unlimited access to food (a standard diet) and water. The experiment was started when the mice were 5 weeks of age and continued for 4 weeks. Each group comprised 8–10 mice. The ob/ob mice received daily intraperitoneal (i.p.) injections of vehicle (saline) or 3–10 mg kg−1 JNJ-5207852; the mice in the 10 mg kg−1 JNJ-5207852 group received a single loading dose of 30 mg kg−1 JNJ-5207852 on the first day of the experiment. The C57BL/6 mice received either saline or 10 mg kg−1 JNJ-5207852. Dosing was started at 09:00 h every day. Body weights were measured using a Sartorius BL1500 scale daily just prior to dosing.

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Effect of JNJ-5207852 on locomotor activity in rats [1]
Experimentally naïve, male, Sprague–Dawley rats weighing 282–334 g were used. The animals were individually housed with free access to food and water. The animal colony was maintained at 22±2°C during a 12-h light/12-h dark illumination cycle with lights on from 06:00 to 18:00 h. Behavioral testing occurred during the light phase between 08:30 and 14:30 h.
Prior to starting the experiment, animals were handled and given a 1-week acclimation period to the animal colony. At the time of testing, animals were placed into activity chambers for a 6 h test session. The test session consisted of a 2 h habituation period, followed by a 4 h observation period. To assure that there were no pre-existing group differences in activity levels prior to the initiation of treatment, LMA was monitored and recorded during a 2 h habituation period. Following the 2 h habituation period, testing was briefly interrupted and animals were s.c. injected with either saline (1 ml kg−1; n=6), JNJ-5207852 (3, 10, 30 mg kg−1; n=6–7 animals/group) or D-amphetamine (0.75 mg kg−1; n=6). Testing was immediately resumed following the compound injection and LMA was continuously monitored during the remainder of the test session.

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Pharmacokinetics of JNJ-5207852 [1]
A total of 16 male and female Sprague–Dawley rats (four rats/gender/formulation) exhibiting good general health were selected for this study and were assigned to two dose groups. The intravenous (i.v.) formulation was prepared as a solution in 10% solutol/5% dextrose at a nominal concentration of 5.0 mg ml−1. The oral formulation was prepared as a suspension in 0.5% methocel at a nominal concentration of 15 mg ml−1. On day 1 and following an overnight fast, animals were weighed (body weight range: 258–307 g) and each formulation was administered to a group of four male and four female rats. The i.v. formulation was administered by jugular venipuncture at a dose volume of 2 ml kg−1. The oral formulation was administered by gavage at a dose volume of 2 ml kg−1. Following dose administration, blood samples (0.25–0.40 ml) were collected from each animal by jugular venipuncture under isoflurane anesthesia. Blood samples were collected (using lithium heparin as the anticoagulant) at pre-dose and again at 0.08 (i.p. only), 0.25 (oral only), 0.33 (i.p. only), 0.5 (oral only), 1, 2, 4, 8, and 24 h post-dose. Blood samples were placed on ice, pending centrifugation. Following centrifugation, plasma was harvested and stored at approximately −20°C, pending analysis of JNJ-5207852 using an LC assay with a lower limit of quantification of 5 ng ml−1. In addition to the above, brains were collected from all animals (snap frozen in liquid nitrogen or in methanol/dry ice mixture) following collection of the last blood sample. Animals were killed by exsanguination and brains were stored at −20°C pending analysis for JNJ-5207852. The oral bioavailability was calculated relative to the mean AUC value calculated for the i.v.-treated animals.

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Drug treatments [2]
In experiment 2, there were two control groups (C57BL/6J, n = 8 and Balb/c, n = 8) which received physiological saline, and the other groups (n = 8 each) received a single injection of one dose each of methimepip (1, 2.5, and 5 mg/kg i.p.). In experiment 3, there were also two control groups (C57BL/6J, n = 8 and Balb/c, n = 8) which received physiological saline, and three Balb/c groups (n = 8 each) which received a single injection of one dose each of JNJ-5207852 (0.5, 1, and 5 mg/kg i.p) 30 min before introduction to the 3D maze. Methimepip and JNJ-5207852 were kind gifts from Professor Rob Leurs and Dr. Nicholas Curruthers (JNJ, USA), respectively. Selection of drug doses was based on previous in vivo studies (e.g., Kitbunnadaj et al., 2005; Jia et al., 2006).

Oral and i.v. pharmacokinetics of JNJ-5207852 [1]
JNJ-5207852 was dosed orally at 30 mg kg−1 and i.p. at 10 mg kg−1 to four male and female rats. The average plasma concentrations are shown in Figure 8. JNJ-5207852 appeared to be orally absorbed in a moderately fast manner, with Tmax values of 4.5 and 4.0 h for males and females, respectively. A slow elimination was suggested by average half-life values of 14.6 and 16.8 h for males and females, respectively. Following i.p. administration, half-life values were calculated at 13.2 and 20.1 h for males and females, respectively. The mean volume of distribution was 100070 and 105737 ml kg−1 for males and females, respectively, which suggests extensive distribution outside the plasma. The average oral bioavailability of JNJ-5207852 was high in both sexes at 107 and 85% for males and females, respectively.
The concentration of JNJ-5207852 in the brains was also determined at the 24-h time point. The concentrations after oral dosing were 5306±282 ng ml−1 in males and 6726±826 ng ml−1 in females. After i.p. dosing brain levels of 2096±46 and 2483±54 ng ml−1 were reached in males and females, respectively. These data suggest extensive brain penetration and retention.

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Pharmacokinetics experiments revealed that JNJ-5207852 is extensively absorbed after oral administration. It has excellent brain penetration and a relatively long half-life (13–20 h after i.v. administration). One of the most striking characteristics of JNJ-5207852 is its high volume of distribution (more than 100,000 ml kg−1), suggestive of extensive tissue distribution. Thus, JNJ-5207852 may be an excellent tool for probing H3 receptor function. [1]

[1]. Acute wake-promoting actions of JNJ-5207852, a novel, diamine-based H3 antagonist. Br J Pharmacol. 2004 Nov;143(5):649-61.

[2]. Effects of methimepip and JNJ-5207852 in Wistar rats exposed to an open-field with and without object and in Balb/c mice exposed to a radial-arm maze. Front Syst Neurosci. 2012 Jul 16;6:54.

1 1-[4-(3-piperidin-1-yl-propoxy)-benzyl]-piperidine (JNJ-5207852) is a novel, non-imidazole histamine H3 receptor antagonist, with high affinity at the rat (pKi=8.9) and human (pKi=9.24) H3 receptor. JNJ-5207852 is selective for the H3 receptor, with negligible binding to other receptors, transporters and ion channels at 1 microm. 2 JNJ-5207852 readily penetrates the brain tissue after subcutaneous (s.c.) administration, as determined by ex vivo autoradiography (ED50 of 0.13 mg kg(-1) in mice). In vitro autoradiography with 3H-JNJ-5207852 in mouse brain slices shows a binding pattern identical to that of 3H-R-alpha-methylhistamine, with high specific binding in the cortex, striatum and hypothalamus. No specific binding of 3H-JNJ-5207852 was observed in brains of H3 receptor knockout mice. 3 In mice and rats, JNJ-5207852 (1-10 mg kg(-1) s.c.) increases time spent awake and decreases REM sleep and slow-wave sleep, but fails to have an effect on wakefulness or sleep in H3 receptor knockout mice. No rebound hypersomnolence, as measured by slow-wave delta power, is observed. The wake-promoting effects of this H3 receptor antagonist are not associated with hypermotility. 4 A 4-week daily treatment of mice with JNJ-5207852 (10 mg kg(-1) i.p.) did not lead to a change in body weight, possibly due to the compound being a neutral antagonist at the H3 receptor. 5 JNJ-5207852 is extensively absorbed after oral administration and reaches high brain levels. 6 The data indicate that JNJ-5207852 is a novel, potent and selective H3 antagonist with good in vitro and in vivo efficacy, and confirm the wake-promoting effects of H3 receptor antagonists. [1]

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We addressed the possibility that JNJ-5207852 might be an inverse agonist. Due to the difficulty in obtaining a consistent degree of constitutive activity in our cell-based system, we were not able to answer this question definitively using a functional signal transduction assay. Instead, we used a method which relies on the differential binding behavior of neutral antagonists vs inverse agonists to coupled and uncoupled receptors (Childers & Snyder, 1980). Inverse agonists have a higher affinity for the uncoupled state of the receptor, agonists have a lower affinity for the uncoupled state, and the affinity of neutral antagonists is unaffected by the coupling state. Thus, the ratio of the Ki value obtained in the absence of GppNHp/NaCl vs in the presence of these uncoupling conditions is expected to be around 1 for a neutral antagonist, <1 for an agonist and >2 for an inverse agonist. Using this method, we determined that JNJ-5207852, with a Ki ratio of 1.25, is most likely to be a neutral antagonist at the H3 receptor.
In summary, JNJ-5207852 is a potent, selective nonimidazole H3 antagonist with clear in vivo efficacy in rodent arousal models and lack of appetite-suppressant effects. It suppresses SWS and increases waking without inducing rebound hypersomnolence, or increasing locomotor activity. JNJ-5207852 thus represents a new pharmacological tool as a neutral antagonist to explore the role of H3 receptors in the regulation of sleep and wakefulness and possibly in related systems such as circadian rhythms, as well as opening up new avenues for the treatment of conditions associated with excessive daytime sleepiness, such as sleep-apnea, multiple sclerosis and fibromyalgia.[1]

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C20H32N2O

316.480885505676

316.251

C, 75.90; H, 10.19; N, 8.85; O, 5.06

398473-34-2

JNJ-5207852 dihydrochloride;1782228-76-5

2766326

Light yellow to yellow solid powder

1.0±0.1 g/cm3

443.4±30.0 °C at 760 mmHg

123.9±21.8 °C

0.0±1.1 mmHg at 25°C

1.542

4.11

0

3

7

23

303

0

O(C1C=CC(=CC=1)CN1CCCCC1)CCCN1CCCCC1

PTKHFRNHJULJKT-UHFFFAOYSA-N

InChI=1S/C20H32N2O/c1-3-12-21(13-4-1)16-7-17-23-20-10-8-19(9-11-20)18-22-14-5-2-6-15-22/h8-11H,1-7,12-18H2

1-{3-[4-(Piperidin-1-ylmethyl)phenoxy]propyl}piperidine

JNJ-5207852; JNJ5207852; 398473-34-2; JNJ-5207,852; JNJ 5207,852 dihydrochloride; 1-[4-(3-piperidinopropoxy)benzyl]piperidine; 1-(4-(3-(piperidin-1-yl)propoxy)benzyl)piperidine; JNJ 5207852; 1-[3-[4-(piperidin-1-ylmethyl)phenoxy]propyl]piperidine; 4I9OVB1G7D; JNJ 5207852

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 : ~77.5 mg/mL (~244.88 mM)

Solubility in Formulation 1: ≥ 2.58 mg/mL (8.15 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 25.8 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: ≥ 2.58 mg/mL (8.15 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 25.8 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: ≥ 2.58 mg/mL (8.15 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 25.8 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.)