piperidines and Hypothermia

Prewarming prior to surgery is effective in preventing perioperative hypothermia. There is a paucity of evidence, however, regarding the hemodynamic effects of prewarming. We hypothesized that the nadir mean arterial pressure during anesthesia induction would be higher after prewarming than after no prewarming.. We randomized 32 patients prior to elective neurosurgery to receive either one hour of forced-air convective warming at 46°C or routine care (full body blanket with convective warmer attached but not turned on). All patients had invasive blood pressure, heart rate, and core temperature monitoring before and during warming and underwent a protocolized intravenous anesthetic induction with propofol and remifentanil target-controlled infusions. The primary endpoint was the nadir mean arterial blood pressure (MAP) during induction. Hypotension was defined as systolic blood pressure (SBP) < 90 mmHg, MAP < 60 mmHg, or a reduction in either SBP or MAP > 20% from baseline values.. No difference was found in the mean (SD) nadir MAP between the prewarmed group and the control group [64 (11) mmHg vs 68 (16) mmHg, respectively; mean difference, 5 mmHg; 95% confidence interval (CI), -6 to 15; P = 0.36]. Similarly, there was no difference between groups in the incidence of hypotension (100% of prewarmed vs 93% of control patients; relative risk, 1.07; 95% CI, 0.94 to 1.23; P = 0.32) or in the requirement for vasopressors during induction (four patients in each group required metaraminol; P = 1.00).. Prewarming with convective forced air for one hour prior to intravenous anesthetic induction did not prevent hypotension during the induction period (Australian New Zealand Clinical Trials Registry [ANZCTR] ACTRN12615000431527).

Topics: Adult; Aged; Anesthetics, Intravenous; Blood Pressure; Body Temperature; Female; Heart Rate; Humans; Hypotension; Hypothermia; Incidence; Male; Metaraminol; Middle Aged; Neurosurgical Procedures; Piperidines; Propofol; Remifentanil

Previous findings showed that inhibitors of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), degrading enzymes of anandamide (2-AEA) and 2-arachidonoylglycerol (2-AG), reduced the nonsteroidal anti-inflammatory drug-induced gastric lesions. The present study aimed to investigate: i./whether central or peripheral mechanism play a major role in the gastroprotective effect of inhibitors of FAAH, MAGL and AEA uptake, ii./which peripheral mechanism(s) may play a role in mucosal protective effect of FAAH, MAGL and uptake inhibitors.. Gastric mucosal damage was induced by acidified ethanol. Gastric motility was measured in anesthetized rats. Catalepsy and the body temperature were also evaluated. Mucosal calcitonin gene-related peptide (CGRP), somatostatin concentrations and superoxide dismutase (SOD) activity were measured. The compounds were injected intraperitoneally (i.p.) or intracerebroventricularly (i.c.v.).. 1. URB 597, JZL184 (inhibitors of FAAH and MAGL) and AM 404 (inhibitor of AEA uptake) decreased the mucosal lesions significantly given either i.c.v. or i.p. 2. URB 937, the peripherally restricted FAAH inhibitor failed to exert significant action injected i.p. 3. Ethanol-induced decreased levels of mucosal CGRP and somatostatin were reversed by URB 597, JZL 184 and AM 404, the decreased SOD activity was elevated significantly by URB 597 and JZL 184. 4. Neither compounds given i.c.v. influenced gastric motility, elicited catalepsy, or hypothermia.. Elevation of central endocannabinoid levels by blocking their degradation or uptake via stimulation of mucosal defensive mechanisms resulted in gastroprotective action against ethanol-induced mucosal injury. These findings might suggest that central endocannabinoid system may play a role in gastric mucosal defense and maintenance of mucosal integrity.

Topics: Analysis of Variance; Animals; Arachidonic Acids; Benzamides; Benzodioxoles; Calcitonin Gene-Related Peptide; Carbamates; Catalepsy; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Routes; Endocannabinoids; Ethanol; Gastric Mucosa; Gastrointestinal Motility; Hypothermia; Male; Piperidines; Rats; Rats, Wistar; Somatostatin; Stomach Diseases; Superoxide Dismutase

Cannabinoid-induced tetrad is a preclinical model commonly used to evaluate if a pharmacological compound is an agonist of the central type-1 cannabinoid (CB1) receptor in rodents. The tetrad is characterized by hypolocomotion, hypothermia, catalepsy, and analgesia, four phenotypes that are induced by acute administration of CB1 agonists exemplified by the prototypic cannabinoid delta-9-tetrahydrocannabinol (THC). This unit describes a standard protocol in mice to induce tetrad phenotypes with THC as reference cannabinoid. We provide typical results obtained with this procedure showing a dose effect of THC in different mouse strains. The effect of the CB1 antagonist rimonabant is also shown. This tetrad protocol is well adapted to reveal new compounds acting on CB1 receptors in vivo. © 2017 by John Wiley & Sons, Inc.

Topics: Animals; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Catalepsy; Disease Models, Animal; Dronabinol; Exploratory Behavior; Hypothermia; Male; Mice; Mice, Inbred C57BL; Movement Disorders; Piperidines; Pyrazoles; Rimonabant

Cannabis is a recreational drug leading to intoxication, following stimulation of cannabinoid CB. Cannabinoid receptor antagonists have been widely used and so may provide an acceptable single-dose antidote to cannabinoid intoxication. This use may save human life, where the life-threatening effects are mediated by cannabinoid receptors and not off-target influences of the synthetic cannabinoids or non-cannabinoids within the recreational drug mixture.

Topics: Animals; Antidotes; Cannabinoid Receptor Agonists; Drug Inverse Agonism; Female; Hypothermia; Mice; Mice, Biozzi; Naphthalenes; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1

Monoacylglycerol lipase (MAGL) is a serine hydrolase that acts as a principal degradative enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG). In addition to terminating the signaling function of 2-AG, MAGL liberates arachidonic acid to be used as a primary source for neuroinflammatory prostaglandin synthesis in the brain. MAGL activity also contributes to cancer pathogenicity by producing precursors for tumor-promoting bioactive lipids. Pharmacological inhibitors of MAGL provide valuable tools for characterization of MAGL and 2-AG signaling pathways. They also hold great therapeutic potential to treat several pathophysiological conditions, such as pain, neurodegenerative disorders, and cancer. We have previously reported piperidine triazole urea, {4-[bis-(benzo[d][1,3]dioxol-5-yl)methyl]-piperidin-1-yl}(1H-1,2,4-triazol-1-yl)methanone (JJKK-048), to be an ultrapotent and highly selective inhibitor of MAGL in vitro. Here, we characterize in vivo effects of JJKK-048. Acute in vivo administration of JJKK-048 induced a massive increase in mouse brain 2-AG levels without affecting brain anandamide levels. JJKK-048 appeared to be extremely potent in vivo. Activity-based protein profiling revealed that JJKK-048 maintains good selectivity toward MAGL over other serine hydrolases. Our results are also the first to show that JJKK-048 promoted significant analgesia in a writhing test with a low dose that did not cause cannabimimetic side effects. At a high dose, JJKK-048 induced analgesia both in the writhing test and in the tail-immersion test, as well as hypomotility and hyperthermia, but not catalepsy.

Topics: Animals; Arachidonic Acids; Behavior, Animal; Benzodioxoles; Brain; Dose-Response Relationship, Drug; Endocannabinoids; Enzyme Inhibitors; Glycerides; Hypothermia; Male; Mice; Monoacylglycerol Lipases; Nociception; Piperidines; Pyrazoles; Rimonabant

Growing evidence shows cannabidiol (CBD) modulates some of the effects of Δ(9) -tetrahydrocannabinol (THC). CBD is a constituent of some strains of recreational cannabis but its content is highly variable. High CBD strains may have less memory-impairing effects than low-CBD strains and CBD can reverse behavioural effects of THC in monkeys. CBD/THC interactions in rodents are more complicated as CBD can attenuate or exacerbate the effects of THC. This study was undertaken to determine if CBD could reverse hypothermia or hypolocomotor effects caused by THC in rats.. Male Sprague-Dawley rats were prepared with radiotelemetry devices and then given doses of THC (10-30 mg·kg(-1) , i.p.) with or without CBD. Experiments determined the effect of simultaneous or 30 min pretreatment with CBD in a 1:1 ratio with THC, as well as the effect of CBD in a 3:1 ratio. Additional experiments determined the effects of pretreatment with the cannabinoid CB1 receptor antagonist SR141716 (rimonabant).. CBD did not attentuate THC-induced hypothermia or hypolocomotion but instead exaggerated these effects in some conditions. The antagonist SR141716 blocked hypolocomotor effects of THC for the first hour after injection and the hypothermia for 6 h; thus validating the pharmacological model.. There is no evidence from this study that elevated CBD content in cannabis could provide protection from the physiological effects of THC, in rats.

Topics: Animals; Body Temperature; Cannabidiol; Cannabinoid Receptor Antagonists; Dronabinol; Hypothermia; Male; Motor Activity; Piperidines; Pyrazoles; Rats, Sprague-Dawley; Rimonabant; Telemetry

JWH-018 is a synthetic CB1 and CB2 agonist illegally marketed as products named "Spice" or "herbal blend" for its psychoactive effects which are much higher than those produced by cannabis. In the last year, the European Monitoring Centre for Drugs and Drug Addiction reported to the Italian National Early Warning System the seizure of plant material containing new halogenated derivatives of JWH-018 (JWH-018 Cl and JWH-018 Br). The present study aimed to investigate the in vitro and in vivo activity of these two new synthetic cannabinoids in mice. In vitro competition binding experiments performed on mouse and human CB1 receptors revealed a high affinity and potency of the halogenated compounds. Synthetic cannabinoids (0.01-6 mg/kg i.p.) impaired motor activity and induced catalepsy in mice and their effects were more severe with respect to those evoked by Δ(9)-THC. Moreover, they increased the mechanical and thermal pain threshold and induced a marked hypothermia. It is interesting to note that whereas high doses of JWH-018 cause seizures, myoclonia and hyperreflexia, the halogenated compounds, in particular JWH-018Br, were less effective. Behavioral and neurological changes were prevented by the selective CB1 receptor antagonist AM 251. These data demonstrate for the first time that JWH-018 Cl and JWH-018 Br act similarly to JWH-018 while inducing less convulsive episodes and myoclonias. These data support the hypothesis that the halogenated compounds may have been introduced onto market to produce similar intoxicating effects as JWH-018 while causing less side effects.

Topics: Animals; Binding, Competitive; Cannabinoid Receptor Agonists; Cannabinoids; Catalepsy; CHO Cells; Cricetulus; Halogenation; Humans; Hypothermia; Indoles; Male; Mice, Inbred ICR; Motor Activity; Naphthalenes; Pain Threshold; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Reflex, Abnormal; Seizures

High-content screening led to the identification of the N-isobutylamide guineensine from Piper nigrum as novel nanomolar inhibitor (EC50=290nM) of cellular uptake of the endocannabinoid anandamide (AEA). Noteworthy, guineensine did not inhibit endocannabinoid degrading enzymes fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL) nor interact with cannabinoid receptors or fatty acid binding protein 5 (FABP5), a major cytoplasmic AEA carrier. Activity-based protein profiling showed no inhibition of serine hydrolases. Guineensine also inhibited the cellular uptake of 2-arachidonoylglycerol (2-AG). Preliminary structure-activity relationships between natural guineensine analogs indicate the importance of the alkyl chain length interconnecting the pharmacophoric isobutylamide and benzodioxol moieties for AEA cellular uptake inhibition. Guineensine dose-dependently induced cannabimimetic effects in BALB/c mice shown by strong catalepsy, hypothermia, reduced locomotion and analgesia. The catalepsy and analgesia were blocked by the CB1 receptor antagonist rimonabant (SR141716A). Guineensine is a novel plant natural product which specifically inhibits endocannabinoid uptake in different cell lines independent of FAAH. Its scaffold may be useful to identify yet unknown targets involved in endocannabinoid transport.

Topics: Alkenes; Amidohydrolases; Analgesics; Animals; Arachidonic Acids; Biological Transport; Brain; Cannabinoid Receptor Antagonists; Catalepsy; Dose-Response Relationship, Drug; Endocannabinoids; Fatty Acid-Binding Proteins; Glycerides; Heterocyclic Compounds, 2-Ring; Humans; Hypothermia; Locomotion; Male; Mice; Mice, Inbred BALB C; Monoacylglycerol Lipases; Neoplasm Proteins; Piper; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Receptors, Cannabinoid; Rimonabant; Serine Endopeptidases; Structure-Activity Relationship; U937 Cells

Several allosteric modulators (AMs) of the CB1 receptor have been characterized in vitro, including Org27569, which enhances CB1-specific binding of [H]CP55,940, but behaves as an insurmountable CB1-receptor antagonist in several biochemical assays. Although a growing body of research has investigated the molecular actions of this unusual AM, it is unknown whether these actions translate to the whole animal. The purpose of the present study was to determine whether Org27569 would produce effects in well-established mouse behavioral assays sensitive to CB1 orthosteric agonists and antagonists. Similar to the orthosteric CB1 antagonist/inverse agonist rimonabant, Org27569 reduced food intake; however, this anorectic effect occurred independently of the CB1 receptor. Org27569 did not elicit CB1-mediated effects alone and lacked efficacy in altering antinociceptive, cataleptic, and hypothermic actions of the orthosteric agonists anandamide, CP55,940, and Δ-tetrahydrocannabinol. Moreover, it did not alter the discriminative stimulus effects of anandamide in FAAH-deficient mice or Δ-tetrahydrocannabinol in wild-type mice in the drug discrimination paradigm. These findings question the utility of Org27569 as a 'gold standard' CB1 AM and underscore the need for the development of CB1 AMs with pharmacology that translates from the molecular level to the whole animal.

Topics: Allosteric Regulation; Amidohydrolases; Animals; Arachidonic Acids; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoid Receptor Modulators; Catalepsy; Cyclohexanols; Dronabinol; Drug Evaluation; Eating; Endocannabinoids; Female; Hypothermia; Indoles; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Nociception; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant

Eating high fat chow increases the sensitivity of male rats to some behavioral effects of the direct-acting dopamine receptor agonist quinpirole; it is not known whether sensitivity to quinpirole is similarly enhanced in female rats eating high fat chow. Female Sprague-Dawley rats had free access to standard chow (5.7% fat) or either free or restricted access (i.e. body weight matched to rats eating standard chow) to high fat (34.3% fat) chow. Quinpirole (0.0032-0.32 mg/kg) produced hypothermia and a low frequency of yawning. Eating high fat chow produced insulin resistance without affecting quinpirole-induced yawning or hypothermia. Pretreatment with the dopamine D2 receptor antagonist L-741,626 failed to increase quinpirole-induced yawning, indicating that the low frequency of yawning was not due to enhanced D2 receptor sensitivity. Compared with younger (postnatal day 75), drug-naive female rats in a previous study, rats in the present study (postnatal day 275) were more sensitive to cocaine-elicited (1-17.8 mg/kg) locomotion and the development of sensitization across 5 weeks; however, eating high fat chow did not further enhance these effects. These results suggest that drug history and age might modulate the effects of diet on sensitivity to drugs acting on dopamine systems.

Topics: Aging; Animals; Body Temperature; Body Weight; Cocaine; Diet, High-Fat; Dietary Fats; Dopamine Agonists; Dopamine D2 Receptor Antagonists; Dopamine Uptake Inhibitors; Dose-Response Relationship, Drug; Eating; Female; Hypothermia; Indoles; Insulin Resistance; Motor Activity; Piperidines; Quinpirole; Rats, Sprague-Dawley; Receptors, Dopamine D2; Yawning

Several effects of the abused synthetic cannabinoid JWH-018 were compared to those of Δ9-tetrahydrocannabinol (Δ9-THC) in rhesus monkeys. JWH-018 (0.1 mg/kg i.v.) was established as a discriminative stimulus and rimonabant was used to examine mechanisms responsible for discrimination as well as operant response rate-decreasing and hypothermic effects. JWH-018 dose-dependently increased drug-lever responding (ED50=0.01 mg/kg) and decreased response rate (ED50=0.064 mg/kg). Among various cannabinoids, the relative potency for producing discriminative stimulus and rate-decreasing effects was the same: CP-55940=JWH-018>Δ9-THC=WIN-55212-2=JWH-073. The benzodiazepine agonist midazolam and the NMDA antagonist ketamine did not exert JWH-018 like discriminative stimulus effects up to doses that disrupted responding. JWH-018 and Δ9-THC decreased rectal temperature by 2.2 and 2.8°C, respectively; the doses decreasing temperature by 2°C were 0.21 and 1.14 mg/kg, respectively. Antagonism did not differ between JWH-018 and Δ9-THC, but did differ among effects. The apparent affinities of rimonabant calculated in the presence of JWH-018 and Δ9-THC were not different from each other for antagonism of discriminative stimulus effects (6.58 and 6.59, respectively) or hypothermic effects (7.08 and 7.19, respectively). Apparent affinity estimates are consistent with the same receptors mediating the discriminative stimulus and hypothermic effects of both JWH-018 and Δ9-THC. However, there was more limited and less orderly antagonism of rate-decreasing effects, suggesting that an additional receptor mechanism is involved in mediating the effects of cannabinoids on response rate. Overall, these results strongly suggest that JWH-018 and Δ9-THC act at the same receptors to produce several of their shared psychopharmacological effects.

Topics: Animals; Benzoxazines; Body Temperature; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Conditioning, Operant; Cyclohexanols; Discrimination Learning; Dronabinol; Hypothermia; Indoles; Macaca mulatta; Male; Morpholines; Naphthalenes; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant

The endocannabinoid signaling system (ECS) has been targeted for developing novel therapeutics since ECS dysfunction has been implicated in various pathologies. Current focus is on chemical modifications of the hexahydrocannabinol (HHC) nabilone (Cesamet(®)).. To characterize the novel, high-affinity cannabinoid receptor 1 (CB(1)R) HHC-ligand AM2389 [9β-hydroxy-3-(1-hexyl-cyclobut-1-yl)-hexahydrocannabinol in two rodent pre-clinical assays.. CB(1)R mediation of AM2389-induced hypothermia in mice was evaluated with AM251, a CB(1)R-selective antagonist/inverse agonist. Additionally, two groups of rats discriminated the full cannabinergic aminoalkylindole AM5983 (0.18 and 0.56 mg/kg) from vehicle 20 min post-injection in a two-choice operant conditioning task motivated by 0.1% saccharin/water. Generalization/substitution tests were conducted with AM2389, AM5983, and Δ(9)-tetrahydrocannabinol (Δ(9)-THC).. Δ(9)-THC (30 mg/kg)-induced hypothermia exhibited a faster onset and shorter duration of action compared with AM2389 (0.1 and 0.3 mg/kg). AM251 (3 and 10 mg/kg) attenuated/blocked hypothermia induced by 0.3 mg/kg AM2389. In drug discrimination, the order of potency was AM2389 > AM5983 > Δ(9)-THC with ED(50) values of 0.0025, 0.0571, and 0.2635 mg/kg, respectively, in the low-dose condition. The corresponding ED(50) values in the high-dose condition were 0.0069, 0.1246, and 0.8438 mg/kg, respectively. Onset of the effects of AM2389 was slow with a protracted time-course; the functional, perceptual in vivo half-life was approximately 17 h.. This potent cannabinergic HHC exhibited a slow onset of action with a protracted time-course. The AM2389 chemotype appears well suited for further drug development, and AM2389 currently is used to probe behavioral consequences of sustained ECS activation.

Topics: Animals; Benzopyrans; Conditioning, Operant; Discrimination, Psychological; Dose-Response Relationship, Drug; Dronabinol; Drug Interactions; Hypothermia; Indoles; Male; Mice; Mice, Inbred C57BL; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Time Factors

Cannabinoid (CB) receptor agonists are expected to alleviate ischemic brain damage by modulating neurotransmission and neuroinflammatory responses via CB(1) and CB(2) receptors, respectively. In a previous study, TAK-937, a novel potent and selective CB(1) and CB(2) receptor agonist, was shown to exert significant cerebroprotective effects accompanied by hypothermia after transient middle cerebral artery occlusion (MCAO) in rats. Sustained hypothermia itself induces significant neuroprotective effects. In the present studies, we examined the relative contribution of hypothermia and CB(1) receptor activation to the cerebroprotective effects of TAK-937.. Using a multichannel brain temperature controlling system we developed, the brain temperature of freely moving rats was telemetrically monitored and maintained between 37 and 38°C during intravenous infusion of TAK-937 (100 µg/kg/h) or vehicle for 24 h after 2 h MCAO. AM251, a selective CB(1) receptor antagonist, was administered intraperitoneally at 30 mg/kg 30 min before starting intravenous infusion of TAK-937 (100 µg/kg/h) for 24 h. Rats were sacrificed and their brains were isolated 26 h after MCAO in both experiments. When the hypothermic effect of TAK-937 was completely reversed by a brain temperature controlling system, the infarct-reducing effect of TAK-937 was attenuated in part, but remained significant. On the other hand, concomitant AM251 treatment with TAK-937 completely abolished the hypothermic and infarct-reducing effects of TAK-937.. We conclude that the cerebroprotective effects of TAK-937 were at least in part mediated by induction of hypothermia, and mainly mediated by CB(1) receptor activation.

Topics: Amides; Animals; Benzofurans; Body Temperature; Disease Models, Animal; Hypothermia; Infarction, Middle Cerebral Artery; Male; Neuroprotective Agents; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1

Pitolisant (BF2.649) is a selective inverse agonist for the histamine H(3) receptor and was developed for the treatment of excessive daytime sleepiness in Parkinson disease, narcolepsy, and schizophrenia. Since H(3)-ligands can decrease inflammatory pain, we tested Pitolisant in inflammatory and neuropathic pain models. MATERIALS AND TREATMENTS: Behavioral effects of pitolisant and the structural different H(3) receptor inverse agonists ciproxifan and ST-889 were tested in zymosan-induced inflammation and the spared nerve injury model for neuropathic pain.. Responses to mechanical and thermal stimuli were determined. Calcium imaging was performed with primary neuronal cultures of dorsal root ganglions.. Clinically relevant doses of pitolisant (10 mg/kg) had no relevant effect on mechanical or thermal pain thresholds in all animal models. Higher doses (50 mg/kg) dramatically increased thermal but not mechanical pain thresholds. Neither ciproxifan nor ST-889 altered thermal pain thresholds. In peripheral sensory neurons high concentrations of pitolisant (30-500 μM), but not ciproxifan, partially inhibited calcium increases induced by capsaicin, a selective activator of transient receptor potential vanilloid receptor 1 (TRPV1). High doses of pitolisant induced a strong hypothermia.. The data show a dramatic effect of high dosages of pitolisant on the thermosensory system, which appears to be H(3) receptor-independent.

Topics: Animals; Behavior, Animal; Calcium; Cells, Cultured; Ganglia, Spinal; Histamine Agonists; Histamine H3 Antagonists; Hot Temperature; Hypothermia; Imidazoles; Mice; Pain; Pain Threshold; Piperidines; Psychomotor Performance

Physiological alterations that may change pharmacological response accompany aging. Pharmacokinetic/pharmacodynamic properties of cholinesterase inhibitors (ChEIs) used in the treatment of Alzheimer's disease, donepezil, tacrine, and galantamine, were investigated in an aged Lister hooded rat model. Intravenous and oral 6-h blood sampling profiles in old (30 months old) and young (7 months old) rats revealed pharmacokinetic changes similar to those in humans with an approximately 40% increase in C(max) of galantamine and prolonged t(1/2) (1.4-fold) and mean residence time (1.5-fold) of donepezil. Tacrine disposition was maintained with age, and area under the concentration-time curve and clearance in old rats were similar to those in young rats for all drugs tested as was bioavailability. Old rats showed a trend of increased pharmacodynamic sensitivity (<20%) to ChEIs in cholinesterase activity assays, which was attributed to pharmacokinetic effects because a trend of higher blood and brain concentrations was seen in the old rats although brain/blood ratios remained unaffected. Enhanced cholinergic-mediated behaviors such as tremor, hypothermia, salivation, and lacrimation were also observed in the old rats, which could not be accounted for by a similar magnitude of change in pharmacokinetics. A decrease in expression of muscarinic acetylcholine receptor subtype 2 detected in old rat brains was postulated to play a role. Greater age effects in both pharmacokinetics and pharmacodynamics of donepezil and tacrine were seen in previous studies with Fischer 344 rats, indicating a potential risk in overreliance on this rat strain for aging studies.

Topics: Aging; Animals; Biological Availability; Brain; Cholinesterase Inhibitors; Cholinesterases; Donepezil; Dose-Response Relationship, Drug; Galantamine; Half-Life; Hypothermia; Indans; Male; Metabolic Clearance Rate; Piperidines; Random Allocation; Rats; Rats, Inbred Strains; Receptor, Muscarinic M2; Salivation; Tacrine; Tears; Tremor

Cannabinoid CB(1) receptor agonists vary in efficacy in vitro; however, relationships between efficacy and behavioral effects are unclear.. This study examined the relationship between apparent CB(1) agonist efficacy and in vivo effects.. Male C57BL/6J mice responded for food under a fixed ratio 30 schedule; rectal temperature was measured. Sensitivity of the mice to cannabinoid agonists (rank order efficacy in vitro reported to be CP 55940 > anandamide > Δ(9)-tetrahydrocannabinol; Δ(9)-THC) and a non-cannabinoid (the benzodiazepine midazolam) was determined before, during, and after discontinuation of daily Δ(9)-THC treatment (32 mg/kg/day, i.p.). Rimonabant was combined with cannabinoids to examine whether CB(1) receptors mediated effects on response rate.. Δ(9)-THC, CP 55940, anandamide, and midazolam decreased responding at doses smaller than those producing hypothermia. Rimonabant antagonized the rate-decreasing effects of Δ(9)-THC and CP 55940, but not those of anandamide. Δ(9)-THC treatment produced tolerance for both rate-decreasing and hypothermic effects. Δ(9)-THC treatment did not change sensitivity to the rate-decreasing effects of CP 55940, but produced cross-tolerance to CP 55940 for hypothermic effects. Δ(9)-THC treatment did not modify sensitivity to anandamide and midazolam.. CB(1) receptors mediate the operant rate-decreasing effects of Δ(9)-THC and CP 55940, but not anandamide, in mice. CB(1) agonist efficacy is an important determinant of in vivo effects, especially with regard to the magnitude of tolerance and cross-tolerance resulting from daily Δ(9)-THC treatment. This applies not only to different cannabinoids when measuring the same effect but also to the same cannabinoid when measuring different effects.

Topics: Animals; Behavior, Animal; Cannabinoids; Conditioning, Operant; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Tolerance; Hypothermia; Male; Mice; Mice, Inbred C57BL; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant; Time Factors

Hypothermia occurs in the most severe cases of systemic inflammation, but the mechanisms involved are poorly understood. This study evaluated whether the hypothermic response to bacterial lipopolysaccharide (LPS) is modulated by the endocannabinoid anandamide(AEA) and its receptors: cannabinoid-1 (CB1), cannabinoid-2 (CB2) and transient receptor potential vanilloid-1 (TRPV1). In rats exposed to an ambient temperature of 22◦C, a moderate dose of LPS (25 - 100 μg kg−1 I.V.) induced a fall in body temperature with a nadir at ∼100 minpostinjection. This response was not affected by desensitization of intra-abdominal TRPV1 receptors with resiniferatoxin (20 μg kg - 1 I.P.), by systemic TRPV1 antagonism with capsazepine(40mg kg−1 I.P.), or by systemic CB2 receptor antagonism with SR144528 (1.4 mg kg−1 I.P.).However, CB1 receptor antagonism by rimonabant (4.6mg kg−1 I.P.) or SLV319 (15mg kg−1 I.P.)blocked LPS hypothermia. The effect of rimonabant was further studied. Rimonabant blocked LPS hypothermia when administered I.C.V. at a dose (4.6 μg) that was too low to produce systemic effects. The blockade of LPS hypothermia by I.C.V. rimonabant was associated with suppression of the circulating level of tumour necrosis factor-α. In contrast to rimonabant,the I.C.V. administration of AEA (50 μg) enhanced LPS hypothermia. Importantly, I.C.V. AEAdid not evoke hypothermia in rats not treated with LPS, thus indicating that AEA modulates LPS-activated pathways in the brain rather than thermo effector pathways. In conclusion, the present study reveals a novel, critical role of brain CB1 receptors in LPS hypothermia. Brain CB1 receptors may constitute a new therapeutic target in systemic inflammation and sepsis.

Topics: Analysis of Variance; Animals; Arachidonic Acids; Body Temperature Regulation; Brain; Camphanes; Capsaicin; Disease Models, Animal; Diterpenes; Endocannabinoids; Female; Hypothermia; Injections, Intraperitoneal; Injections, Intravenous; Injections, Intraventricular; Lipopolysaccharides; Male; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Long-Evans; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Signal Transduction; Sulfonamides; Time Factors; TRPV Cation Channels

In recent years, there has been increasing interest in hypothermia induced by paracetamol for therapeutic purposes, which, in some instances, has been reported as a side effect. Understanding the mechanism by which paracetamol induces hypothermia is therefore an important question. In this study, we investigated whether the novel metabolite of paracetamol, N-(4-hydroxyphenyl)arachidonylamide (AM404), which activates the cannabinoid (CB) and transient receptor potential vanilloid-1 (TRPV1) systems, mediates the paracetamol-induced hypothermia. The hypothermic response to 300 mg/kg paracetamol in CB(1) receptor (CB(1)R) and TRPV1 knockout mice was compared to wild-type mice. Hypothermia induced by paracetamol was also investigated in animals pretreated with the CB(1)R or TRPV1 antagonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperdinyl-1H-pyrazole-3-carboxamide trifluoroacetate salt (AM251) or 4'-chloro-3-methoxycinnamanilide (SB366791), respectively. In CB(1)R or TRPV1 knockout mice, paracetamol induced hypothermia to the same extent as in wild-type mice. In addition, in C57BL/6 mice pretreated with AM251 or SB366791, paracetamol induced hypothermia to the same extent as in control mice. AM404 failed to induce hypothermia at pharmacological doses. Inhibition of fatty acid amide hydrolase (FAAH), which is involved in the metabolism of paracetamol to AM404, did not prevent the development of hypothermia with paracetamol. Paracetamol also induced hypothermia in FAAH knockout mice to the same extent as wild-type mice. We conclude that paracetamol induces hypothermia independent of cannabinoids and TRPV1 and that AM404 does not mediate this response. In addition, potential therapeutic value of combinational drug-induced hypothermia is supported by experimental evidence.

Topics: Acetaminophen; Amidohydrolases; Anilides; Animals; Arachidonic Acids; Cannabinoids; Cinnamates; Hypothermia; Hypothermia, Induced; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; TRPV Cation Channels

Cannabinoid receptor CB1 is expressed abundantly in the brain and presumably in the peripheral tissues responsible for energy metabolism. It is unclear if the antiobesity effects of rimonabant, a CB1 antagonist, are mediated through the central or the peripheral CB1 receptors. To address this question, we generated transgenic mice with central nervous system (CNS)-specific knockdown (KD) of CB1, by expressing an artificial microRNA (AMIR) under the control of the neuronal Thy1.2 promoter. In the mutant mice, CB1 expression was reduced in the brain and spinal cord, whereas no change was observed in the superior cervical ganglia (SCG), sympathetic trunk, enteric nervous system, and pancreatic ganglia. In contrast to the neuronal tissues, CB1 was undetectable in the brown adipose tissue (BAT) or the liver. Consistent with the selective loss of central CB1, agonist-induced hypothermia was attenuated in the mutant mice, but the agonist-induced delay of gastrointestinal transit (GIT), a primarily peripheral nervous system-mediated effect, was not. Compared to wild-type (WT) littermates, the mutant mice displayed reduced body weight (BW), adiposity, and feeding efficiency, and when fed a high-fat diet (HFD), showed decreased plasma insulin, leptin, cholesterol, and triglyceride levels, and elevated adiponectin levels. Furthermore, the therapeutic effects of rimonabant on food intake (FI), BW, and serum parameters were markedly reduced and correlated with the degree of CB1 KD. Thus, KD of CB1 in the CNS recapitulates the metabolic phenotype of CB1 knockout (KO) mice and diminishes rimonabant's efficacy, indicating that blockade of central CB1 is required for rimonabant's antiobesity actions.

Topics: Adiponectin; Adiposity; Animals; Anti-Obesity Agents; Biomarkers; Body Weight; Central Nervous System; Cholesterol; Diet, High-Fat; Energy Intake; Gastrointestinal Transit; Hypothermia; Insulin; Leptin; Mice; Mice, Knockout; Mice, Transgenic; MicroRNAs; Mutation; Obesity; Peripheral Nervous System; Phenotype; Piperidines; Promoter Regions, Genetic; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant; Triglycerides

To investigate whether drugs targeting peripheral cannabinoid-1 (CB1) receptor ameliorate adiposity comparable to central CB1-receptor antagonist or not.. Receptor binding assay and functional assay in vitro. Pharmacokinetic parameters in mice, brain uptake clearance of compounds in rats and antagonism on the CB1-agonist-induced hypothermia in mice. Diet consumption, body weight changes, hepatic gene expression of sterol-regulatory element-binding protein-1 (SREBP-1) and plasma/tissue concentrations of compounds in HF diet-induced obese (HF-DIO) mice after acute and chronic treatment.. Compound-1, an SR141716A derivative, is a peripheral CB1-receptor-selective antagonist that is 10 times less potent than SR141716A in in vitro evaluations. Although the plasma concentrations of Compound-1 are five times higher than those of SR141716A, its potency is still 10 times lower than that of SR141716A in reducing the consumption of normal or HF diet by mice. Through evaluations of brain uptake and the effect on CB1-agonist-induced hypothermia, it was verified that the blood-brain barrier (BBB) penetration of Compound-1 is much lower than that of SR141716A. In HF-DIO mice, chronic treatment by Compound-1 showed dose-dependent antiobesity activities, while its brain distribution was very low as compared with that of SR141716A. Compound-1's effective doses for antiobesity activity were just over 30 mg kg(-1). However, Compound-1 completely suppressed the elevated hepatic SREBP-1 expression even at 10 mg kg(-1).. These results suggest that (1) central CB1 receptors mediate anorectic response of CB1-receptor antagonists and (2) peripheral modulations, including SREBP-1 expression, are not major mechanisms in the antiobesity effects of CB1-receptor antagonists.

Topics: Adiposity; Animals; Benzoxazines; Brain; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Feeding Behavior; Hypothermia; Male; Mice; Mice, Inbred C57BL; Morpholines; Naphthalenes; Obesity; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Rimonabant; Sterol Regulatory Element Binding Protein 1; Tissue Distribution

F15599 is a novel agonist with high selectivity and efficacy at serotonin 5-HT(1A) receptors (5-HT(1A)Rs). In signal transduction, electrophysiological and neurochemical tests, F15599 preferentially activates post-synaptic 5-HT(1A)Rs in rat frontal cortex. Such a profile may translate to an improved profile of therapeutic activity for mood disorders. The in-vivo effects of F15599 were therefore compared with those of a related compound, F13714, in rat models of antidepressant activity and 5-HT(1A)R activation: forced swimming test (FST), conditioned stress-induced ultrasonic vocalization, 5-HT syndrome, plasma corticosterone and body temperature. Acute administration of F15599 or F13714 reduced immobility in the FST at low doses; these effects were long lasting and the effects of F15599 were maintained after repeated (5 d, p.o.) administration. Both compounds decreased ultrasonic vocalization duration at low doses. In contrast, higher doses of F15599 were required to induce lower lip retraction, elements of the 5-HT behavioural syndrome, hypothermia and to increase plasma corticosterone levels. Notably, there was a greater separation of ED50 between FST and other effects for F15599 than for F13714. Thus, the in-vivo potency of F15599 in models of antidepressant/anti-stress activity is similar to that of F13714, despite the fact that the latter has an in-vitro potency two orders of magnitude greater. In contrast F15599 has a lower propensity than F13714 to induce other serotonergic signs. The distinctive pharmacological profile of F15599 suggests that preferential targeting of post-synaptic 5-HT(1A)Rs constitutes a promising strategy for improved antidepressant therapy.

Topics: Aminopyridines; Animals; Antidepressive Agents; Corticosterone; Depression; Hypothermia; Male; Models, Animal; Molecular Targeted Therapy; Motor Activity; Piperidines; Prefrontal Cortex; Pyrimidines; Rats; Rats, Sprague-Dawley; Rats, Wistar; Serotonin; Serotonin 5-HT1 Receptor Agonists; Stress, Physiological; Swimming

Several lines of evidence support a role for the endogenous opioid system in mediating behaviors associated with drug dependence. Specifically, recent findings suggest that the kappa-opioid receptor (KOR) may play a role in aspects of nicotine dependence, which contribute to relapse and continued tobacco smoking.. The objective of this study is to determine the involvement of the KOR in the initial behavioral responses of nicotine, nicotine reward, and nicotine withdrawal using the highly selective KOR antagonist JDTic. JDTic doses of 1, 4, 8, or 16 mg/kg were administered subcutaneously (s.c.) 18 h prior to nicotine treatment.. JDTic dose-dependently blocked acute nicotine-induced antinociception in the tail-flick but not the hot-plate test and did not significantly attenuate morphine's antinociceptive effect in either the tail-flick or hot-plate test. Furthermore, JDTic (8 and 16 mg/kg, s.c.) failed to block the expression of nicotine reward as measured by the conditioned place preference model. In contrast, JDTic and the KOR antagonist norBNI attenuated the expression of both the physical (somatic signs and hyperalgesia) and affective (anxiety-related behavior and conditioned place aversion) nicotine withdrawal signs.. Our findings clearly show that the KOR is involved in mediating the withdrawal aspects of nicotine dependence. The results from this study suggest that blockade of the KOR by selective KOR antagonists may be useful smoking cessation pharmacotherapies.

Topics: Analgesics; Animals; Anxiety; Buprenorphine; Dose-Response Relationship, Drug; Hyperalgesia; Hypothermia; Male; Mice; Morphine; Nicotine; Piperidines; Receptors, Opioid, kappa; Reward; Substance Withdrawal Syndrome; Tetrahydroisoquinolines

Salvinorin A, the primary psychoactive derivative of the hallucinogenic herb Salvia divinorum, is a potent and highly selective kappa-opioid receptor (KOR) agonist. Several recent studies, however, have suggested endocannabinoid system mediation of some of its effects.. This study represents a systematic examination of this hypothesis.. Salvinorin A was isolated from S. divinorum and was evaluated in a battery of in vitro and in vivo procedures designed to detect cannabinoid activity, including CB(1) receptor radioligand and [(35)S]GTPgammaS binding, calcium flux assay, in vivo cannabinoid screening tests, and drug discrimination.. Salvinorin A did not bind to nor activate CB(1) receptors. In vivo salvinorin A produced pronounced hypolocomotion and antinociception (and to a lesser extent, hypothermia). These effects were blocked by the selective KOR antagonist, JDTic, but not by the CB(1) receptor antagonist rimonabant. Interestingly, however, rimonabant attenuated KOR activation stimulated by U69,593 in a [(35)S]GTPgammaS assay. Salvinorin A did not substitute for Delta(9)-tetrahydrocannabinol (THC) in mice trained to discriminate THC.. These findings suggest that similarities in the pharmacological effects of salvinorin A and those of cannabinoids are mediated by its activation of KOR rather than by any direct action of salvinorin A on the endocannabinoid system. Further, the results suggest that rimonabant reversal of salvinorin A effects in previous studies may be explained in part by rimonabant attenuation of KOR activation.

Topics: Animals; Calcium; Cannabinoid Receptor Modulators; Discrimination Learning; Diterpenes, Clerodane; Dronabinol; Guanosine 5'-O-(3-Thiotriphosphate); Hypothermia; Locomotion; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Pain Measurement; Piperidines; Pyrazoles; Radioligand Assay; Receptor, Cannabinoid, CB1; Receptors, Opioid, kappa; Rimonabant; Salvia; Tetrahydroisoquinolines

In contrast to the numerous reports on the pharmacological effects of Δ(9)-tetrahydrocannabinol (THC), the pharmacological activity of another substituent of Cannabis sativa, cannabichromene (CBC) remains comparatively unknown. In the present study, we investigated whether CBC elicits cannabinoid activity in the tetrad assay, which consists of the following four endpoints: hypomotility, antinociception, catalepsy, and hypothermia. Because cannabinoids are well documented to possess anti-inflammatory properties, we examined CBC, THC, and combination of both phytocannabinoids in the lipopolysaccharide (LPS) paw edema assay. CBC elicited activity in the tetrad that was not blocked by the CB(1) receptor antagonist, rimonabant. Moreover, a behaviorally inactive dose of THC augmented the effects of CBC in the tetrad that was associated with an increase in THC brain concentrations. Both CBC and THC elicited dose-dependent anti-inflammatory effects in the LPS-induced paw edema model. The CB(2) receptor, SR144528 blocked the anti-edematous actions of THC, but not those produced by CBC. Isobolographic analysis revealed that the anti-edematous effects of these cannabinoids in combination were additive. Although CBC produced pharmacological effects, unlike THC, its underlying mechanism of action did not involve CB(1) or CB(2) receptors. In addition, there was evidence of a possible pharmacokinetic component in which CBC dose-dependently increased THC brain levels following an i.v. injection of 0.3mg/kg THC. In conclusion, CBC produced a subset of behavioral activity in the tetrad assay and reduced LPS-induced paw edema through a noncannabinoid receptor mechanism of action. These effects were augmented when CBC and THC were co-administered.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Camphanes; Cannabinoids; Cannabis; Catalepsy; Dose-Response Relationship, Drug; Dronabinol; Hallucinogens; Hypothermia; Inflammation; Male; Mice; Mice, Inbred ICR; Motor Activity; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant

Food restriction enhances sensitivity to the reinforcing effects of a variety of drugs of abuse including opiates, nicotine, and psychostimulants. Food restriction has also been shown to alter a variety of behavioral and pharmacological responses to dopaminergic agonists, including an increased sensitivity to the locomotor stimulatory effects of direct- and indirect-dopamine agonists, elevated extracellular dopamine levels in responses to psychostimulants, as well as suppression of agonist-induced yawning. Behavioral and molecular studies suggest that augmented dopaminergic responses observed in food-restricted animals result from a sensitization of the dopamine D2 receptor; however, little is known about how food restriction affects dopamine D3 receptor function. The current studies were aimed at better defining the effects of food restriction on D2 and D3 receptor function by assessing the capacity of N'-propyl-4,5,6,7-tetrahydrobenzothiazole-2,6-diamine dihydrochloride (pramipexole) to induce yawning, penile erection (PE), hypothermia, and locomotor activity in free-fed and food-restricted rats. Food restriction resulted in a suppression of pramipexole-induced yawning, a sensitized hypothermic response, and an enhanced locomotor response to pramipexole, effects that are suggestive of an enhanced D2 receptor activity; no effect on pramipexole-induced PE was observed. Antagonist studies further supported a food restriction-induced enhancement of the D2 receptor activity because the D2 antagonist 3-[4-(4-chlorophenyl)-4-hydroxypiperidin-l-yl]methyl-1H-indole (L741,626) recovered pramipexole-induced yawning to free-fed levels, whereas yawning and PE were suppressed following pretreatment with the D3 antagonist N-{4-[4-(2,3-dichlorophenyl)-piperazin-1-yl]-trans-but-2-enyl}-4-pyridine-2-yl-benzamide hydrochloride (PG01037). The results of the current studies suggest that food restriction sensitized rats to the D2-mediated effects of pramipexole while having no effect on the D3-mediated effects of pramipexole.

Topics: Animals; Benzamides; Benzothiazoles; Dopamine Agonists; Dopamine D2 Receptor Antagonists; Food; Hypothermia; Indoles; Male; Motor Activity; Penile Erection; Physostigmine; Piperazines; Piperidines; Pramipexole; Pyridines; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D2; Receptors, Dopamine D3; Yawning

The present study used the endpoint of hypothermia to investigate cannabinoid and nociceptin/orphanin FQ (N/OFQ) interactions in conscious animals. Prior work has established that cannabinoids produce hypothermia by activating central cannabinoid CB(1) receptors. The administration of N/OFQ into the brain also causes significant hypothermia. Those data suggest a link between cannabinoid CB(1) receptors and N/OFQ peptide (NOP) receptors in the production of hypothermia. Therefore, we determined if NOP receptor activation is required for cannabinoid-evoked hypothermia and if cannabinoid CB(1) receptor activation is necessary for N/OFQ-induced hypothermia. In actual experiments, a cannabinoid agonist, WIN 55212-2 (2.5, 5, and 10 mg/kg, i.p.), caused significant hypothermia in male Sprague-Dawley rats (200-225 g). A NOP receptor antagonist, JTC-801 (1 mg/kg, i.p.), did not affect body temperature. For combined administration, JTC-801 (1 mg/kg, i.p.) blocked a significant proportion of the hypothermia caused by each dose of WIN 55212-2 (2.5, 5, and 10 mg/kg, i.p.). JTC-801 (1 mg/kg, i.p.) also blocked the hypothermia caused by another cannabinoid agonist, CP-55, 940 (1 mg/kg, i.p.). In separate experiments, the direct administration of N/OFQ (9 microg/rat, i.c.v.) into the brain produced significant hypothermia. The hypothermic effect of N/OFQ was blocked by JTC-801 (1 mg/kg, i.p.) but not by a selective cannabinoid CB(1) antagonist, SR 141716A (5 mg/kg, i.m.). The finding that a NOP receptor antagonist abolishes a significant percentage of cannabinoid-induced hypothermia suggests that NOP receptor activation is required for cannabinoids to produce hypothermia. This interaction, quantitated in the present study, is the first evidence that NOP receptors mediate a cannabinoid-induced effect in conscious animals.

Topics: Aminoquinolines; Analgesics; Animals; Benzamides; Benzoxazines; Body Temperature; Cannabinoids; Humans; Hypothermia; Male; Morpholines; Naphthalenes; Narcotic Antagonists; Nociceptin Receptor; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptors, Opioid; Rimonabant

Although the cannabinoid CB(1) antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR 141716A) blocks many of the in vivo effects of cannabinoids, the antagonist activity of SR 141716A is limited under some conditions. The general aims of this study were to: 1) examine whether the limited antagonist activity of SR 141716A generalizes to the cannabinoid CB(1) antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM 251); and 2) examine mechanisms by which cannabinoids produce hypothermia, catalepsy, and hypoactivity in C57BL/6J mice. SR 141716A and AM 251 were administered alone and in combination with the cannabinoid agonists triangle up(9)-tetrahydrocannabinol (triangle up(9)-THC) and R-(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)-methyl]pyrrolol-[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl) methanone (WIN 55212-2). triangle up(9)-THC and WIN 55212-2 produced catalepsy, hypothermia, and hypoactivity with similar potency; WIN 55212-2 produced greater hypothermia than triangle up(9)-THC, otherwise differences in maximal effect were not detected in the other assays. When administered alone, the antagonists did not produce catalepsy or alter body temperature and they decreased locomotor activity. SR 1417167A and AM 251 blocked catalepsy and hypothermia, and partially attenuated hypoactivity, produced by triangle up(9)-THC and WIN 55212-2. While the antagonists were equipotent in blocking agonist-induced hypothermia, SR 141716A was 6-fold more potent than AM 251 in blocking agonist-induced catalepsy. The results demonstrate that SR 141716A and AM 251 have strikingly similar behavioral activity, i.e., they block some and not other in vivo effects of cannabinoid agonists, and further demonstrate differences in the maximum effect of cannabinoid agonists that might be related to differences in agonist efficacy. While the results strongly suggest that cannabinoid CB(1) receptors mediate the hypothermic and cataleptic effects of cannabinoids, differences in the relative potency of antagonists suggest that mechanisms responsible for these effects are not identical.

Topics: Animals; Benzoxazines; Cannabinoids; Catalepsy; Dose-Response Relationship, Drug; Dronabinol; Hypothermia; Injections, Intraperitoneal; Mice; Mice, Inbred C57BL; Morpholines; Motor Activity; Naphthalenes; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant; Time Factors

A series of new 2-substituted 1,1-dioxo-1,2,6-thiadiazine-5-carboxylate derivatives have been prepared from monosubstituted sulfamides in order to obtain N-substituted 1,1-dioxo-1,2,6-thiadiazine-5-carboxamides as novel cannabinoid derivatives, analogues of Rimonabant (SR141716A). Their potential functional activity on cannabinoid receptors has been evaluated in vitro and in vivo in mice, showing that two compounds (37 and 39) behave as cannabinoid agonists in vitro. Their potency is lower than that of the reference compound, WIN 55,212-2, but their efficacy is similar to that of this cannabinoid agonist, although no in vivo activity is observed. Another derivative (38) behaves as a cannabinoid antagonist both in vitro and in vivo, being its efficacy and potency similar to that of the well-known antagonist SR141716A.

Topics: Animals; Benzoxazines; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Catalepsy; Dose-Response Relationship, Drug; Drug Design; Drug Evaluation, Preclinical; Hypothermia; Injections, Intraperitoneal; Locomotion; Male; Mice; Mice, Inbred ICR; Molecular Structure; Morpholines; Naphthalenes; Pain Measurement; Piperidines; Pyrazoles; Receptors, Cannabinoid; Rimonabant; Stereoisomerism; Thiadiazines; Vas Deferens

AM 404 inhibits endocannabinoid uptake and enhances the cannabinoid CB(1)-mediated effects of endogenous cannabinoids. Accumulating evidence also suggests that AM 404 acts at sites other than the endocannabinoid system. One site is the transient receptor potential vanilloid 1 cation channel (TRPV1). A useful endpoint for discriminating between TRPV1- or CB(1)-mediated effects of AM 404 is hypothermia. This is because TRPV1 or CB(1) receptor activation produces a significant hypothermia in rats. The present study investigated the effects of AM 404 (1, 5, 10 and 20 mg/kg, i.p.) on body temperature in rats and the involvement of TRPV1 and CB(1) receptors in the effects of AM 404. Doses of 10 and 20 mg/kg of AM 404 produced significant hypothermia. Pre-treatment with capsazepine (30 mg/kg, i.p.) blocked the hypothermia caused by 10 and 20 mg/kg of AM 404. Pre-treatment with SB 366791 (2 mg/kg, i.p.), a new TRPV1 antagonist, also abolished the hypothermia evoked by AM 404 (20 mg/kg, i.p.). In contrast, pre-treatment with SR 141716A (Rimonabant), a CB(1) antagonist, or AA-5-HT, a fatty acid amide hydrolase (FAAH) blocker, did not affect AM 404-evoked hypothermia. The present data demonstrate that AM 404 evokes a significant hypothermia in rats that is dependent on TRPV1 receptor activation.

Topics: Amidohydrolases; Anilides; Animals; Arachidonic Acids; Body Temperature; Capsaicin; Cinnamates; Endocannabinoids; Hypothermia; Male; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Rimonabant; TRPV Cation Channels

Series of thiazoles, triazoles, and imidazoles were designed as bioisosteres, based on the 1,5-diarylpyrazole motif that is present in the potent CB(1) receptor antagonist rimonabant (SR141716A, 1). A number of target compounds was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The thiazoles, triazoles, and imidazoles elicited in vitro( )()CB(1) antagonistic activities and in general exhibited considerable CB(1) vs CB(2) receptor subtype selectivities, thereby demonstrating to be cannabinoid bioisosteres of the original diarylpyrazole class. Some key representatives in the imidazole series showed potent pharmacological in vivo activities after oral administration in both a CB agonist-induced hypotension model and a CB agonist-induced hypothermia model. Molecular modeling studies showed a close three-dimensional structural overlap between the key compound 62 and rimonabant. A structure-activity relationship (SAR) study revealed a close correlation between the biological results in the imidazole and pyrazole series.

Topics: Administration, Oral; Animals; CHO Cells; Cricetinae; Cricetulus; Cyclohexanols; Hypotension; Hypothermia; Imidazoles; Mice; Models, Molecular; Molecular Conformation; Piperidines; Pyrazoles; Radioligand Assay; Rats; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Stereoisomerism; Structure-Activity Relationship; Thiazoles; Triazoles

The present study investigated a potential role for cannabinoid CB(1) and CB(2) receptors in capsaicin-evoked hypothermia. Capsaicin (1 mg/kg, s.c.) caused rapid and significant hypothermia in rats. Pretreatment with SR 141716A (1, 2.5 and 5 mg/kg, i.p.), a CB(1) antagonist, or SR 144528 (1, 2.5 and 5 mg/kg, i.p.), a CB(2) antagonist, did not affect capsaicin-induced hypothermia. In separate experiments, the hypothermia caused by WIN 55212-2 (5 mg/kg, i.m.), a cannabinoid agonist, was not significantly altered by capsazepine (10 and 30 mg/kg, i.p.) or SB 366791 (2 mg/kg, i.p.), a novel TRPV1 antagonist. These data suggest that capsaicin causes hypothermia by a CB(1)- and CB(2)-independent mechanism, and that WIN 55212-2 causes hypothermia by a TRPV1-independent mechanism.

Topics: Anilides; Animals; Benzoxazines; Body Temperature; Calcium Channel Blockers; Camphanes; Capsaicin; Cinnamates; Hypothermia; Male; Morpholines; Naphthalenes; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; TRPV Cation Channels

The 5-HT(7) receptor is a recent addition to the 5-HT receptor family and to date there is no clear idea as to its potential role in the CNS. The receptor has been mapped by in situ hybridization and 5-HT(7)-like immunoreactivity and has been detected in discrete areas of the brain including the hypothalamus (Oliver et al., 1999). This suggests the receptor may be involved in temperature regulation and have shown that a selective 5-HT(7) receptor antagonist reverses the hypothermic effect of 5-CT in guinea-pigs. The current study confirmed that the 5-HT(7) receptor antagonists, SB-269970 (1-30 mg/kg, i.p.) and SB-258719 (5-20 mg/kg, i.p.), but not the 5-HT(1A) receptor antagonist, WAY 100635(0.1-1 mg/kg, s.c.), or the 5-HT(1B/D) antagonist, GR127935 (1.25-5 mg/kg, i.p.), reversed the hypothermic effect of 5-CT in mice. In addition the effect of 5-CT on body temperature was examined on 5-HT(7) receptor null mutant mice. 5-CT (0.1-1 mg/kg, i.p.) significantly reduced rectal temperature in wildtype but not 5-HT(7) receptor knockout mice. This suggests that the hypothermic effects of 5-CT are mediated through the 5-HT(7) receptor. All procedures were carried out in accordance with the UK Animals (Scientific Procedures) Act (1986).

Topics: Animals; Body Temperature; Hypothermia; Injections, Intraventricular; Mice; Mice, Knockout; Phenols; Piperidines; Receptors, Serotonin; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Sulfonamides

The dopamine D(3) receptor agonist PD 128907 decreased body temperature in the rat. The selective dopamine D(3) and D(4) receptor antagonists, A-437203 and L-745,870, respectively, did not prevent this effect. In contrast, PD 128907-induced hypothermia was antagonized by SCH 23390, a selective D(1) receptor antagonist, and by L-741,626, a selective D(2) receptor antagonist. Moreover, the selective D(2) receptor agonist trihydroxy-N-n-propylnoraporphine (TNPA) elicited a robust hypothermia which was prevented by pretreatment with L-741,626 but not by A-437203. In agreement with previous data obtained in D(3) knock-out mice, present results suggest that D(2) rather than D(3) receptors mediate dopamine receptor agonist-induced hypothermia in rats. In addition, it appears that both D(1) and D(2) receptors may be involved in a cooperative manner.

Topics: Animals; Aporphines; Benzazepines; Benzopyrans; Body Temperature Regulation; Dopamine Agonists; Dopamine Antagonists; Hypothermia; Indoles; Oxazines; Piperazines; Piperidines; Pyridines; Pyrimidines; Pyrroles; Rats; Rats, Wistar; Receptors, Dopamine D1; Receptors, Dopamine D2; Receptors, Dopamine D3; Receptors, Dopamine D4

Repeated THC administration produces motivational and somatic adaptive changes leading to dependence in rodents. To investigate the molecular basis for cannabinoid dependence and its possible relationship with the endogenous opioid system, we explored delta9-tetrahydrocannabinol (THC) activity in mice lacking mu-, delta- or kappa-opioid receptor genes. Acute THC-induced hypothermia, antinociception, and hypolocomotion remained unaffected in these mice, whereas THC tolerance and withdrawal were minimally modified in mutant animals. In contrast, profound phenotypic changes are observed in several place conditioning protocols that reveal both THC rewarding and aversive properties. Absence of microreceptors abolishes THC place preference. Deletion of kappa receptors ablates THC place aversion and furthermore unmasks THC place preference. Thus, an opposing activity of mu- and kappa-opioid receptors in modulating reward pathways forms the basis for the dual euphoric-dysphoric activity of THC.

Topics: Analysis of Variance; Animals; Behavior, Animal; Cannabinoids; Crosses, Genetic; Dronabinol; Drug Tolerance; Hypothermia; Marijuana Abuse; Mice; Mice, Inbred Strains; Mice, Knockout; Motivation; Motor Activity; Piperidines; Psychotropic Drugs; Pyrazoles; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Reward; Rimonabant; Spatial Behavior; Substance Withdrawal Syndrome

There are now several acetylcholinesterase inhibitors in clinical use for the treatment of Alzheimer's disease, however, no systematic comparative studies of their central and peripheral cholinergic mediated effects in rats appear to have been reported. The present study investigated the dose-response characteristics of donepezil, tacrine, rivastigmine and metrifonate in inducing tremor, lacrimation, salivation and hypothermia and the duration of action of these compounds in Lister hooded rats. Data obtained were compared with the clinical observations on these drugs. Three doses of each compound were given orally to establish a dose-response curve for each behaviour, Tremor and lacrimation were scored, salivation was measured by weighing swabs applied to the mouth area and hypothermia was measured with a rectal probe. ED50 values were calculated for tremor. Using a just sub-maximal tremorigenic dose, the duration of response was examined. All four compounds produced dose-dependent increases in tremor and hypothermia. Only tacrine also produced marked salivation and lacrimation. The order of potency (ED50 value in micromol/kg) was rivastigmine (3.7), donepezil (18.0), tacrine (37.5), metrifonate (470). Tremor following tacrine (150 micromol/kg) and donepezil (20 micromol/kg) was prolonged (> 6 h) with a similar hypothermic response. The duration of these responses following metrifonate (777 micromol/kg) and rivastigmine (12.5 micromol/kg) did not exceed 3 h. Tacrine had poor selectivity for central (tremor) versus peripheral (salivation/lacrimation) effects compared to the other compounds. Donepezil also had a sustained duration of action. The data are consistent with clinical results and indicate that simple in-vivo models may assist in the selection of acetylcholinesterase inhibitors with a suitable response profile for use in the symptomatic treatment of Alzheimer's disease.

Topics: Animals; Body Temperature; Carbamates; Cholinesterase Inhibitors; Donepezil; Dose-Response Relationship, Drug; Hypothermia; Indans; Lacrimal Apparatus; Male; Phenylcarbamates; Piperidines; Rats; Rivastigmine; Saliva; Tacrine; Tremor; Trichlorfon

Tolerance and dependence induced by chronic delta-9-tetrahydrocannabinol (THC) administration were investigated in mice. The effects on body weight, analgesia and hypothermia were measured during 6 days of treatment (10 or 20 mg kg(-1) THC twice daily). A rapid tolerance to the acute effects was observed from the second THC administration. The selective CB-1 receptor antagonist SR 141716A (10 mg kg(-1)) was administered at the end of the treatment, and somatic and vegetative manifestations of abstinence were evaluated. SR 141716A administration precipitated several somatic signs that included wet dog shakes, frontpaw tremor, ataxia, hunched posture, tremor, ptosis, piloerection, decreased locomotor activity and mastication, which can be interpreted as being part of a withdrawal syndrome. Brains were removed immediately after the behavioural measures and assayed for adenylyl cyclase activity. An increase in basal, forskolin and calcium/calmodulin stimulated adenylyl cyclase activities was specifically observed in the cerebellum of these mice. The motivational effects of THC administration and withdrawal were evaluated by using the place conditioning paradigm. No conditioned change in preference to withdrawal associated environment was observed. In contrast, a conditioned place aversion was produced by the repeated pairing of THC (20 mg kg(-1)), without observing place preference at any of the doses used. This study constitutes a clear behavioural and biochemical model of physical THC withdrawal with no motivational aversive consequences. This model permits an easy quantification of THC abstinence in mice and can be useful for the elucidation of the molecular mechanisms involved in cannabinoid dependence.

Topics: Analysis of Variance; Animals; Body Temperature; Body Weight; Conditioning, Psychological; Cyclic AMP; Dronabinol; Drug Interactions; Hallucinogens; Hypothermia; In Vitro Techniques; Male; Mice; Motivation; Narcotics; Pain Measurement; Piperidines; Pyrazoles; Rimonabant; Substance Withdrawal Syndrome

The present study investigated the effects of the cannabinoid receptor agonist CP 55,940 (1-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl) phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol) and the cannabinoid receptor antagonist SR 141716A (N-(piperidin-l-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-me thyl-1 H-pyrazole-3-carboxamide hydrochloride) on ultrasonic vocalizations, body temperature and activity in 11-13-day-old rat pups. Testing occurred in a 5-min session 30 min following drug administration. CP 55,940 produced a dose-dependent decrease in ultrasonic vocalizations, with a 1000-micrograms/kg dose causing an almost complete inhibition of calls. Doses of 100 and 1000 micrograms/kg of CP 55,940, but not 10 micrograms/kg, caused significant hypothermia in the pups and the 1000 micrograms/kg dose also inhibited activity. The cannabinoid receptor antagonist SR 141716A (20 mg/kg) reversed the effects of 1000 micrograms/kg CP 55,940 on ultrasonic vocalizations and body temperature, but the benzodiazepine receptor antagonist flumazenil (20 mg/kg), the dopamine D1 receptor antagonist SCH 23390 (0.5 mg/kg) and the opioid receptor antagonist naloxone (1 mg/kg) did not. When administered alone, SR 141716A (20 mg/kg) increased pup ultrasonic vocalizations without affecting body temperature or activity. These results indicate that cannabinoids modulate ultrasonic vocalization production in rat pups in a manner that is independent of hypothermia. The increase in ultrasonic vocalizations produced by SR 141716A is one of the first reported behavioural effects of this drug and suggests that the endogenous cannabinoid ligand anandamide may be involved in the regulation of ultrasonic vocalizations.

Topics: Analysis of Variance; Animals; Animals, Newborn; Behavior, Animal; Benzazepines; Body Temperature; Cannabinoids; Cyclohexanols; Dopamine Antagonists; Dose-Response Relationship, Drug; Flumazenil; GABA Modulators; Hypothermia; Motor Activity; Naloxone; Narcotic Antagonists; Piperidines; Pyrazoles; Rats; Rimonabant; Vocalization, Animal

In a schizophrenic patient, hypothermia was caused by combined treatment with zotepine, biperiden, and fluphenazine, although combined treatment with zotepine and biperiden had caused no side effects. Other side effects closely resembled those in neuroleptic malignant syndrome.

Topics: Adult; Biperiden; Dibenzothiepins; Drug Therapy, Combination; Fluphenazine; Humans; Hypothermia; Male; Neuroleptic Malignant Syndrome; Piperidines; Schizophrenia

The 3-[(2-ethoxyphenoxy)methyl]piperidine derivatives 3-5 were synthesized and screened as potential antidepressant agents by the reserpine interaction test in mice and the evaluation of reuptake inhibition of biogenic amines in pig brain synaptosomal fractions. In addition, their anticonvulsant activity, tested by pentyleneetrazole antagonism, and approximate acute toxicity were evaluated. In vivo and in vitro tests showed that compounds 3 and 5 possess a biological activity comparable to that of the antidepressant drug viloxazine.

Topics: Animals; Antidepressive Agents; Blepharoptosis; Brain; Desipramine; Dopamine; Drug Evaluation, Preclinical; Ethyl Ethers; Hypothermia; Indicators and Reagents; Mice; Norepinephrine; Phenyl Ethers; Piperidines; Reserpine; Seizures; Serotonin; Structure-Activity Relationship; Synaptosomes; Viloxazine

Topics: Animals; Apomorphine; Brain Chemistry; Clonidine; Dextroamphetamine; Dihydroxyphenylalanine; Dopamine; Drug Combinations; Glycolates; Haloperidol; Hydroxydopamines; Hypothermia; Male; Methysergide; Phenoxybenzamine; Pimozide; Piperidines; Propranolol; Pyrrolidines; Rats; Serotonin; Tyramine