bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential effect of FR122047, a selective cyclo‐oxygenase‐1 inhibitor, in rat chronic models of arthritis
Authors: Ochi Takehiro , Goto Toshio
Published: January 2005

We investigated the effects of FR122047 (1‐[(4,5‐bis(4‐methoxyphenyl)‐2‐thiazoyl)carbonyl]‐4‐methylpiperazine hydrochloride), a selective cyclo‐oxygenase (COX)‐1 inhibitor, in rat type II collagen‐induced arthritis (CIA) and adjuvant‐induced arthritis (AIA).

Using an ex vivo rat whole blood assay, FR122047 (0.032 – 3.2 mg kg−1) inhibited COX‐1‐derived thromboxane (TX) B2 production with ED50 value of 0.059 mg kg−1, indicating that it was orally active, but did not inhibit lipopolysaccharide‐induced prostaglandin (PG) E2 production derived by COX‐2.

Oral administration of FR122047 showed a dose‐dependent anti‐inflammatory effect in rat CIA with ED50 value of 0.56 mg kg−1. This drug also dose dependently suppressed the levels of PGE2 and TXB2 in CIA rat paws with ED50 values of 0.24 and 0.13 mg kg−1, respectively.

FR122047 had no effect in rat AIA model. In contrast, indomethacin, a non‐selective COX inhibitor, was anti‐inflammatory and reduced the formation of PGs in AIA rat paws.

Unlike indomethacin, chronic treatment of FR122047 did not damage the stomach mucosa in CIA rats.

These results demonstrate that COX‐1 contributes to the oedema and the formation of PGE2 and TXB2 in rat CIA model, but not in rat AIA model.

We conclude that FR122047 has an orally active and anti‐inflammatory effect mediated by inhibition of PGE2 and TXB2 produced by COX‐1 at a site of inflammation induced by type II collagen and it may be a useful tool for studying the involvement of COX‐1 in various in vivo models of inflammation.

British Journal of Pharmacology (2002) 135, 782–788; doi:10.1038/sj.bjp.0704511
Pirlindole and dehydropirlindole protect rat cultured neuronal cells against oxidative stress‐induced cell death through a mechanism unrelated to MAO‐A inhibition
Authors: Boland A , Gérardy J , Mossay D , Delapierre D , Seutin V
Published: January 2005

It has been shown that the MAO (monoamine oxidase)‐B inhibitor deprenyl (DPR, selegiline) protects some cell types against oxidative stress. By decreasing H2O2 production, MAO‐A inhibitors could also reduce oxidative stress.

This study reports the effect of the MAO‐A inhibitors, pirlindole (PIR), dehydropirlindole (DHP), brofaromine (BRO) and moclobemide (MCL) on primary‐cultured brain cells exposed to iron‐mediated toxicity. A comparison with trolox (TRO), a hydrosoluble vitamin‐E analogue that protects against such an induced stress, was performed.

Rat hippocampal or cortical cultured cells were exposed either to 2 μM FeSO4 alone or in the presence of PIR, DHP, BRO, DPR, MCL or TRO. Cell survival (lactate‐dehydrogenase measurements, 16 h incubation), intracellular peroxide production (DCF‐fluorescence, 1 h incubation), lipoperoxidation (TBARS‐fluorescence, 6 h incubation) and mitochondrial function (MTT‐test, 16 h incubation) were assessed.

PIR, DHP and TRO significantly protected cultures (P<0.05) against Fe2+‐induced toxicity in a concentration‐dependent manner. The EC50s of these compounds were 6, 12 and 19 μM, respectively, in hippocampal cells. For cortical cell cultures incubated in the presence of iron and PIR or DHP, EC50s were 5 and 6 μM respectively. All Hill coefficients were close to unity. BRO, MCL and DPR were not protective in any type of culture. The IC50s for the inhibition of MAO‐A were 2, 2 and 0.2 μM for PIR, DHP and BRO, respectively. PIR, DHP and TRO, but not DPR, induced a significant decrease in both intracellular peroxide production and lipoperoxidation. They also improved mitochondrial function.

These experiments show that PIR and DHP can protect hippocampal and cortical neurons against oxidative stress at pharmacologically relevant concentrations. This protective effect seems unrelated to inhibition of MAO‐A, but possibly involves free radical scavenging.

British Journal of Pharmacology (2002) 135, 713–720; doi:10.1038/sj.bjp.0704519
Testosterone‐induced vasorelaxation in the rat mesenteric arterial bed is mediated predominantly via potassium channels
Authors: Tep‐areenan Patcharin , Kendall David A , Randall Michael D
Published: January 2005

We have investigated the involvement of nitric oxide and K+ channels in the vasorelaxant responses to physiologically‐relevant concentrations of testosterone in the rat isolated mesenteric arterial bed.

Testosterone (100 pM – 10 μM) elicited concentration‐dependent relaxations in the isolated mesenteric arterial bed (pEC50=9.47 (9.22 – 9.73, 95% CI), maximal relaxation, Rmax=62.8±2.0%, n=6). A nitric oxide synthase (NOS) inhibitor, NG‐nitro‐L‐arginine methyl ester (L‐NAME, 300 μM) or removal of the endothelium significantly inhibited maximal relaxations to testosterone (L‐NAME: Rmax=51.4±1.1%, P<0.01, n=6; endothelium‐denuded: Rmax=46.9±2.8%, P<0.001, n=5).

Raising the extracellular K+ concentration to 30 and 60 mM, or pre‐treatment with 300 μM tetrabutylammonium chloride (TBA), a calcium‐activated K+ channel inhibitor, abolished vasorelaxations induced by testosterone. A selective inhibitor of ATP‐sensitive K+ (KATP) channels, glibenclamide (10 μM) and an inhibitor of voltage‐sensitive K+ (KV) channels, 4‐aminopyridine (4‐AP, 1 mM) did not affect testosterone‐induced responses. Vasorelaxation to 1 μM testosterone was significantly (P<0.05) inhibited by 100 nM charybdotoxin (ChTx), an inhibitor of large conductance calcium‐activated K+ (BKCa) channels (control: 63.3±9.9%, n=6; ChTx: 11.9±12.7%, n=3).

Neither the testosterone receptor antagonist, flutamide (10 μM) nor an aromatase inhibitor, aminoglutethimide (10 μM) inhibited testosterone‐induced responses.

In conclusion, the present findings demonstrate, in the rat isolated mesenteric arterial bed, that testosterone causes acute vasorelaxations at physiologically relevant concentrations which are, in part, mediated via NO‐ and endothelium‐dependent pathways. However, the activation of BKCa channels plays a substantial role in testosterone‐induced vasorelaxation.

British Journal of Pharmacology (2002) 135, 735–740; doi:10.1038/sj.bjp.0704522
Comparison of the ORL1 receptor‐mediated inhibition of noradrenaline release in human and rat neocortical slices
Authors: Rominger Axel , Förster Stefan , Zentner Josef , Dooley David J , McKnight Alexander T , Feuerstein Thomas J , Jackisch Rolf , Vlaskovska Mila
Published: January 2005

The effects of nociceptin/orphanin (N/OFQ) and the selective ORL1 antagonist J‐113397 (1‐[(3R,4R)‐1‐cyclo‐octylmethyl‐3‐hydroxymethyl‐4‐piperidyl]‐3‐ethyl‐1,3‐dihydro‐2H‐benzimidazol‐2‐one) were studied on electrically‐evoked release of [3H]‐noradrenaline ([3H]‐NA) from human and rat neocortical slices. Specimens of human tissue were obtained during neurosurgery.

Slices were preincubated with 0.1 μM[3H]‐NA, superfused in the presence of desipramine, idazoxan, and naloxone (1 μM each), and stimulated electrically up to three times under conditions (4 pulses, 100 Hz, 2 ms, 60 mA) that prevent inhibition of evoked [3H]‐NA release by endogenous modulators accumulating during ongoing stimulation.

N/OFQ decreased electrically‐evoked [3H]‐NA release in both human and rat neocortical slices in a concentration‐dependent manner. The respective pEC50 values were 7.74 [CI95: 7.47, 8.04] and 7.64 [CI95: 7.48, 7.77], and the maximal inhibitions were 36.9%[CI95: 32.4%, 41.8%] and 66.4%[CI95: 61.7%, 72.7%].

N/OFQ (1 μM) inhibited K+ (15 mM)‐evoked [3H]‐NA release from neocortical slices of both species by a similar magnitude, either in the presence or absence of tetrodotoxin.

The nonpeptide ORL1 antagonist J‐113397 competitively attenuated, with similar potency, the inhibition of electrically‐evoked [3H]‐NA release by N/OFQ in both species (pA2 values: human, 8.16 [CI95: 7.64, 8.64]; rat, 8.47 [CI95: 8.27, 8.67]). J‐113397 (0.1 μM) by itself did not alter either the evoked or spontaneous [3H]‐NA release, suggesting that presynaptic ORL1 receptors are not activated by endogenous N/OFQ under the stimulation conditions employed.

This study provides the first evidence that N/OFQ modulates [3H]‐NA release in human neocortex via specific ORL1 receptors most likely located on noradrenergic axon terminals.

British Journal of Pharmacology (2002) 135, 800–806; doi:10.1038/sj.bjp.0704523
Inhibition of slow Ca2+‐activated K+ current by 4‐aminopyridine in rat hippocampal CA1 pyramidal neurones
Authors: Andreasen Mogens
Published: January 2005

The effect of 4‐aminopyridine (4‐AP) on the slow afterhyperpolarization (sAHP) seen after high frequency dendritic or somatic firing was investigated in rat hippocampal CA1 pyramidal neurones (PC). Intracellular recordings were obtained from the distal apical dendrites and somata and suprathreshold depolarizing current pulses were used to evoke a sAHP. The sAHP was blocked by low concentrations of carbacholine (Cch) but insensitive to high concentrations of apamin.

In the presence of extracellular 4‐AP, the first dendritic sAHP evoked was reduced compared to a maximal sAHP evoked in the absence of 4‐AP. The reduction was evident at submillimolar concentration and increased to about 80% with 4 mM 4‐AP.

The stability of the 4‐AP‐induced block was affected by the type of anion used in the electrode solution. With K+ acetate (KAc) or K+ methylsulphate (KMeSO4) containing electrodes, the block was progressively removed during the initial 300 – 400 s of recordings. With KCl containing electrodes, the block remained stable and was 10% larger than that obtained with acetate. Detailed investigations showed that intracellular acetate promotes the removal of the 4‐AP‐induced block in an activity‐dependent manner.

Intracellularly applied 4‐AP also induced an acetate‐sensitive block of the dendritic sAHP.

4‐AP also blocked the somatic sAHP and the stability of the block showed the same sensitivity towards anions as the dendritic sAHP.

Thus 4‐AP appears to block the slow Ca2+‐activated K+ current underlying the sAHP in a complex manner which is sensitive to certain types of anions.

British Journal of Pharmacology (2002) 135, 1013–1025; doi:10.1038/sj.bjp.0704533
Orphanin FQ inhibits capsaicin‐induced thermal nociception in monkeys by activation of peripheral ORL1 receptors
Authors: Ko M C H , Naughton N N , Traynor J R , Song M S , Woods J H , Rice K C , McKnight A T
Published: January 2005

Orphanin FQ (OFQ), an endogenous peptide for ORL1 receptors, has been identified. Although the actions of OFQ have much in common with those of opioid peptides at the cellular level, behavioral studies in rodents seem conflicting.

The aim of this study was to investigate the potential pronociceptive or antinociceptive function of peripheral ORL1 receptors in primates. Experiments were conducted to verify whether local administration of OFQ can attenuate capsaicin‐induced nociception and whether peripheral ORL1 receptors selectively mediate the local action of OFQ in monkeys.

Capsaicin (100 μg) was administered subcutaneously in the tail to locally evoke a nociceptive response (thermal allodynia/hyperalgesia), which was manifested as a reduced tail‐withdrawal latency in normally innocuous 46°C warm water.

Co‐administration of OFQ (1 – 30 μg) with capsaicin in the tail dose‐dependently inhibited thermal nociception. However, a locally effective dose of OFQ (30 μg), when applied in the back, did not inhibit capsaicin‐induced nociception.

OFQ‐induced local antinociception was antagonized by a small dose (10 μg) of J‐113397, a selective ORL1 receptor antagonist, in the tail. Similarly, s.c. administration of 10 μg of J‐113397 in the back did not antagonize local antinociception of OFQ.

In addition, s.c. administration of either OFQ or J‐113397 in the tail alone did not change its thermal nociceptive threshold. Local administration of opioid receptor antagonists selective for mu, kappa, and delta opioid receptors did not antagonize OFQ‐induced local antinociception. Local administration of J‐113397 also did not interfere with the local actions of mu, kappa, and delta opioid agonists in the tail.

These results provide the first functional evidence that activation of peripheral ORL1 receptors produces thermal antinociception in primates and this action is independent of antinociception produced at classical opioid receptors.

British Journal of Pharmacology (2002) 135, 943–950; doi:10.1038/sj.bjp.0704535
Inhibition of the NMDA response by pregnenolone sulphate reveals subtype selective modulation of NMDA receptors by sulphated steroids
Authors: Malayev Andrew , Gibbs Terrell T , Farb David H
Published: January 2005

The neurosteroid pregnenolone sulphate (PS) potentiates N‐methyl‐D‐aspartate (NMDA) receptor mediated responses in various neuronal preparations. The NR1 subunit can combine with NR2A, NR2B, NR2C, or NR2D subunits to form functional receptors. Differential NR2 subunit expression in brain and during development raises the question of how the NR2 subunit influences NMDA receptor modulation by neuroactive steroids.

We examined the effects of PS on the four diheteromeric NMDA receptor subtypes generated by co‐expressing the NR1100 subunit with each of the four NR2 subunits in Xenopus oocytes. Whereas PS potentiated NMDA‐, glutamate‐, and glycine‐induced currents of NR1/NR2A and NR1/NR2B receptors, it was inhibitory at NR1/NR2C and NR1/NR2D receptors.

In contrast, pregnanolone sulphate (3α5βS), a negative modulator of the NMDA receptor that acts at a distinct site from PS, inhibited all four subtypes, but was approximately 4 fold more potent at NR1/NR2C and NR1/NR2D than at NR1/NR2A and NR1/NR2B receptors.

These findings demonstrate that residues on the NR2 subunit are key determinants of modulation by PS and 3α5βS. The modulatory effects of PS, but not 3α5βS, on dose‐response curves for NMDA, glutamate, and glycine are consistent with a two‐state model in which PS either stabilizes or destabilizes the active state of the receptor, depending upon which NR2 subunit is present.

The selectivity of sulphated steroid modulators for NMDA receptors of specific subunit composition is consistent with a neuromodulatory role for endogenous sulphated steroids. The results indicate that it may be possible to develop therapeutic agents that target steroid modulatory sites of specific NMDA receptor subtypes.

British Journal of Pharmacology (2002) 135, 901–909; doi:10.1038/sj.bjp.0704543
Constitutive activation of the neurotensin receptor 1 by mutation of Phe358 in Helix seven
Authors: Barroso Séverine , Richard Françoise , Nicolas‐Ethève Delphine , Kitabgi Patrick , Labbé‐Jullié Catherine
Published: January 2005

The neurotensin receptor 1, NTS1, is a G protein‐coupled receptor with seven transmembrane domains (TM) that mediates most of the known effects of the neuropeptide. Our previous studies have pointed to extracellular loop 3 and adjacent TM7 as being potentially involved in agonist‐induced activation of the NTS1.

Here we investigated residues in these domains that might be involved in transconformational activation of the rat NTS1. Single amino acid mutated receptors were expressed in COS cells and inositol phosphate (IP) and cyclic AMP productions were studied.

The F358A mutation in TM7 resulted in a time‐ and receptor concentration‐dependent increase in spontaneous IP production. At expression levels of 12 pmol mg−1, agonist‐independent IP production was increased 10 fold over basal for the F358A mutant receptor whereas the wild type NTS1 exhibited virtually no spontaneous activity at expression levels of 7.5 pmol mg−1.

Neurotensin remained agonist on the F358A mutant receptor with a maximal effect that amounted to greater than twice basal IP levels. SR 48692 was inverse agonist at the mutant receptor, reversing IP production almost back to the levels measured in wild type NTS1‐transfected cells.

Cyclic AMP production was not constitutively activated with the F358A mutant receptor but was stimulated by neurotensin with the same concentration dependence as that observed with the wild type NTS1.

This is the first report, to our knowledge, of a constitutively active mutant of the NTS1. The data are consistent with TM7 being involved in the transconformational changes that lead to agonist‐induced coupling of the NTS1 to Gq.

British Journal of Pharmacology (2002) 135, 997–1002; doi:10.1038/sj.bjp.0704546
Characterization of an apamin‐sensitive small‐conductance Ca2+‐activated K+ channel in porcine coronary artery endothelium: relevance to EDHF
Authors: Burnham M P , Bychkov R , Félétou M , Richards G R , Vanhoutte P M , Weston A H , Edwards G
Published: January 2005

The apamin‐sensitive small‐conductance Ca2+‐activated K+ channel (SKCa) was characterized in porcine coronary arteries.

In intact arteries, 100 nM substance P and 600 μM 1‐ethyl‐2‐benzimidazolinone (1‐EBIO) produced endothelial cell hyperpolarizations (27.8±0.8 mV and 24.1±1.0 mV, respectively). Charybdotoxin (100 nM) abolished the 1‐EBIO response but substance P continued to induce a hyperpolarization (25.8±0.3 mV).

In freshly‐isolated endothelial cells, outside‐out patch recordings revealed a unitary K+ conductance of 6.8±0.04 pS. The open‐probability was increased by Ca2+ and reduced by apamin (100 nM). Substance P activated an outward current under whole‐cell perforated‐patch conditions and a component of this current (38%) was inhibited by apamin. A second conductance of 2.7±0.03 pS inhibited by d‐tubocurarine was observed infrequently.

Messenger RNA encoding the SK2 and SK3, but not the SK1, subunits of SKCa was detected by RT – PCR in samples of endothelium. Western blotting indicated that SK3 protein was abundant in samples of endothelium compared to whole arteries. SK2 protein was present in whole artery nuclear fractions.

Immunofluorescent labelling confirmed that SK3 was highly expressed at the plasmalemma of endothelial cells and was not expressed in smooth muscle. SK2 was restricted to the peri‐nuclear regions of both endothelial and smooth muscle cells.

In conclusion, the porcine coronary artery endothelium expresses an apamin‐sensitive SKCa containing the SK3 subunit. These channels are likely to confer all or part of the apamin‐sensitive component of the endothelium‐derived hyperpolarizing factor (EDHF) response.

British Journal of Pharmacology (2002) 135, 1133–1143; doi:10.1038/sj.bjp.0704551
Chronic fluoxetine treatment selectively uncouples raphe 5‐HT1A receptors as measured by [35S]‐GTPγS autoradiography
Authors: Pejchal Tina , Foley Melissa A , Kosofsky Barry E , Waeber Christian
Published: January 2005

Selective Serotonin Reuptake Inhibitors (SSRIs) are thought to have a delay in therapeutic efficacy because of the need to overcome the inhibitory influence of raphe 5‐HT1A autoreceptors. Prolonged SSRI administration has been reported to desensitize these autoreceptors. We have used [35S]‐GTPγS autoradiography to determine whether this desensitization occurs at the level of receptor/G protein coupling.

Male mice were injected intraperitoneally once a day with saline or 20 mg kg−1 fluoxetine for either 2 days or 14 days. 5‐HT1A receptor binding and coupling to G proteins were assessed using [3H]‐8‐OH‐DPAT and [35S]‐GTPγS autoradiography, respectively.

The 5‐HT receptor agonist 5‐carboxamidotryptamine (5‐CT) stimulated [35S]‐GTPγS binding in the substantia nigra, as well as in hippocampus and dorsal raphe nucleus. The 5‐HT1A receptor antagonist p‐MPPF (4‐fluoro‐N‐(2‐[4‐(2‐methoxyphenyl)1‐piperazinyl]ethyl)‐N‐(2‐pyridinyl)benzamide) blocked this effect in the latter regions, whereas the 5‐HT1B/D antagonist GR‐127,935 (2′‐methyl‐4′‐(5‐methyl‐[1,2,4]oxadiazol‐3‐yl)‐biphenyl‐4‐carboxylic acid [4‐methoxy‐3‐(4‐methyl‐piperazin‐l‐yl)‐phenyl]‐amide) only decreased labelling in substantia nigra.

Fourteen‐day fluoxetine treatment decreased 5‐CT‐stimulated [35S]‐GTPγS binding in dorsal raphe (saline: 112±12% stimulation; fluoxetine: 66±13%), but not in substantia nigra (99±14% vs 103±7%) or hippocampus (157±3% vs 148±18%). Two‐day fluoxetine treatment did not alter 5‐CT‐stimulated [35S]‐GTPγS binding in any of the brain areas investigated.

Decreased [35S]‐GTPγS binding was not due to receptor down‐regulation, since the density of raphe [3H]‐8‐OH‐DPAT binding sites was unaffected by fluoxetine treatment.

These results suggest that the desensitization of presynaptic 5‐HT1A receptor function occurs at the level of receptor‐G protein interaction on dorsal raphe neurons, and may underlie the therapeutic efficacy of long‐term SSRI treatment.

British Journal of Pharmacology (2002) 135, 1115–1122; doi:10.1038/sj.bjp.0704555
Effect of agmatine on locus coeruleus neuron activity: possible involvement of nitric oxide
Authors: Ruiz‐Durántez Eduardo , Ruiz‐Ortega José A , Pineda Joseba , Ugedo Luisa
Published: January 2005

To investigate whether agmatine (the proposed endogenous ligand for imidazoline receptors) controls locus coeruleus neuron activity and to elucidate its mechanism of action, we used single‐unit extracellular recording techniques in anaesthetized rats.

Agmatine (10, 20 and 40 μg, i.c.v.) increased in a dose‐related manner the firing rate of locus coeruleus neurons (maximal increase: 95±13% at 40 μg).

I1‐imidazoline receptor ligands stimulate locus coeruleus neuron activity through an indirect mechanism originated in the paragigantocellularis nucleus via excitatory amino acids. However, neither electrolytic lesions of the paragigantocellularis nucleus nor pretreatment with the excitatory amino acid antagonist kynurenic acid (1 μmol, i.c.v.) modified agmatine effect (10 μg, i.c.v.).

After agmatine administration (20 μg, i.c.v.), dose‐response curves for the effect of clonidine (0.625 – 10 μg kg−1 i.v.) or morphine (0.3 – 4.8 mg kg−1 i.v.) on locus coeruleus neurons were not different from those obtained in the control groups.

Pretreatment with the nitric oxide synthase inhibitors Nω‐nitro‐L‐arginine (10 μg, i.c.v.) or Nω‐nitro‐L‐arginine methyl ester (100 μg, i.c.v.) but not with the less active stereoisomer Nω‐nitro‐D‐arginine methyl ester (100 μg, i.c.v.) completely blocked agmatine effect (10 and 40 μg, i.c.v.).

Similarly, when agmatine (20 pmoles) was applied into the locus coeruleus there was an increase that was blocked by Nω‐nitro‐L‐arginine methyl ester (100 μg, i.c.v.) in the firing rate of the locus coeruleus neurons (maximal increase 53±11% and 14±10% before and after nitric oxide synthase inhibition, respectively).

This study demonstrates that agmatine stimulates the firing rate of locus coeruleus neurons via a nitric oxide synthase‐dependent mechanism located in this nucleus.

British Journal of Pharmacology (2002) 135, 1152–1158; doi:10.1038/sj.bjp.0704556
Evidence of a novel site mediating anandamide‐induced negative inotropic and coronary vasodilatator responses in rat isolated hearts
Authors: Ford William R , Honan Stuart A , White Richard , Hiley C Robin
Published: January 2005

Cannabinoids are known to cause coronary vasodilatation and reduce left ventricular developed pressure (LVDP) in isolated hearts although the identity of the receptor(s) mediating these responses is unknown. Our objective was to pharmacologically characterize cannabinoid receptors mediating cardiac responses to the endocannabinoid, anandamide.

Dose‐response curves for coronary perfusion pressure (CPP) and LVDP were constructed to anandamide, R‐(+)‐methanandamide, palmitoylethanolamide (PEA) and JWH015 in isolated Langendorff‐perfused rat hearts. Anandamide dose‐response curves were also constructed in the presence of antagonists selective for CB1, CB2 or VR1 receptors.

Anandamide and methanadamide significantly reduced CPP and LVDP but the selective CB2 receptor agonists, PEA and JWH015 had no significant effect, compared with equivalent vehicle doses.

Single bolus additions of the selective CB1‐receptor agonist, ACEA (5 nmol), decreased LVDP and CPP. When combined with JWH015 (5 nmol) these responses were not augmented.

Anandamide‐mediated reductions in CPP were significantly blocked by the selective CB1 receptor antagonists SR 141716A (1 μM) and AM251 (1 μM) and the selective CB2 receptor antagonist SR 144528 (1 μM) but not by another selective CB2 receptor antagonist AM630 (10 μM) nor the vanilloid VR1 receptor antagonist capsazepine (10 μM).

SR 141716A, AM281 and SR 144528 significantly blocked negative inotropic responses to anandamide that were not significantly affected by AM251, AM630 and capsazepine.

One or more novel sites mediate negative inotropic and coronary vasodilatatory responses to anandamide. These sites can be distinguished from classical CB1 and CB2 receptors, as responses are sensitive to both SR 141716A and SR 144528.

British Journal of Pharmacology (2002) 135, 1191–1198; doi:10.1038/sj.bjp.0704565
Ca2+ signalling by recombinant human CXCR2 chemokine receptors is potentiated by P2Y nucleotide receptors in HEK cells
Authors: Werry Tim D , Christie Mark I , Dainty Ian A , Wilkinson Graeme F , Willars Gary B
Published: January 2005

Human embryonic kidney (HEK)‐293 cells expressing recombinant Gαi‐coupled, human CXC chemokine receptor 2 (CXCR2) were used to study the elevation of the intracellular [Ca2+] ([Ca2+]i) in response to interleukin‐8 (IL‐8) following pre‐stimulation of endogenously expressed P2Y1 or P2Y2 nucleotide receptors.

Pre‐stimulation of cells with adenosine 5′‐triphosphate (ATP) revealed a substantial Ca2+ signalling component mediated by IL‐8 (Emax=83±8% of maximal ATP response, pEC50 of IL‐8 response=9.7±0.1).

1 μM 2‐methylthioadenosine 5′‐diphosphate (2MeSADP; P2Y1 selective) and 100 μM uridine 5′‐triphosphate (UTP; P2Y2 selective) stimulated equivalent maximal increases in [Ca2+]i elevation. However, UTP caused a sustained elevation, whilst following 2MeSADP [Ca2+]i rapidly returned to basal levels.

Both UTP and 2MeSADP increased the potency and magnitude of IL‐8‐mediated [Ca2+]i elevation but the effects of UTP (Emax of IL‐8 response increased to 50±1% of the maximal response to ATP, pEC50 increased to 9.8±0.1) were greater than those of 2MeSADP (Emax increased to 36±2%, pEC50 increased to 8.7±0.2).

The potentiation of IL‐8‐mediated Ca2+ signalling by UTP was not dependent upon the time of IL‐8 addition following UTP but was dependent on the continued presence of UTP. Potentiated IL‐8 Ca2+ signalling was apparent in the absence of extracellular Ca2+, demonstrating the release of Ca2+ from intracellular stores.

Activation of P2Y1 and P2Y2 receptors also revealed Ca2+ signalling by an endogenously expressed, Gαs‐coupled β‐adrenoceptor.

In conclusion, pre‐stimulation of P2Y nucleotide receptors, particularly P2Y2, facilitates Ca2+ signalling by either recombinant CXCR2 or endogenous β‐adrenoceptors.

British Journal of Pharmacology (2002) 135, 1199–1208; doi:10.1038/sj.bjp.0704566
Tachykinins via Tachykinin NK2 receptor activation mediate ozone‐induced increase in the permeability of the tracheal mucosa in guinea‐pigs
Authors: Fu Li , Kaneko Takeshi , Ikeda Hirotada , Nishiyama Harumi , Suzuki Shunsuke , Okubo Takao , Trevisani Marcello , Geppetti Pierangelo , Ishigatsubo Yoshiaki
Published: January 2005

Acute exposure to ozone is known to cause airway hyperresponsiveness, which, at least in part, seems to result from an increase in the permeability of the airway mucosa. Recently, we demonstrated that depletion of sensory neuropeptides inhibits the ozone‐induced increase in the permeability of the tracheal mucosa in guinea‐pigs. The aim of this study was to determine whether tachykinins mediate ozone‐induced increase in the permeability of the tracheal mucosa in guinea‐pigs.

Anaesthetized guinea‐pigs were exposed to either 3 p.p.m. ozone or filtered air for 30 min. Immediately after exposure, a tracheal segment was isolated in vivo and administered with horseradish peroxidase (HRP). The permeability was assessed by monitoring the appearance of HRP in the blood.

A low dose of NKA increased the permeability of the tracheal mucosa, whereas a low dose of SP was without effect. Low and high doses of the selective NK3 receptor agonist, senktide, were also without effect. The effect of a low dose of NKA was abolished by the NK2 receptor antagonist, SR‐48,968. A high dose of SP increased the permeability in a manner reversible by the NK1 receptor antagonist, CP‐96,345.

Pretreatment with SR‐48,968 completely inhibited the ozone‐induced increase in the permeability, whereas CP‐96,345 had no effect.

It is thus concluded that endogenous tachykinins mediate the ozone‐induced increase in the permeability of the tracheal mucosa in guinea‐pigs mainly via NK2 receptor activation.

British Journal of Pharmacology (2002) 135, 1331–1335; doi:10.1038/sj.bjp.0704572
Enhancement of 1α,25‐dihydroxyvitamin D3‐induced differentiation of human leukaemia HL‐60 cells into monocytes by parthenolide via inhibition of NF‐κB activity
Authors: Kang S N , Kim S H , Chung S W , Lee M H , Kim H J , Kim T S
Published: January 2005

Transcription factors such as NF‐κB provide powerful targets for drugs to use in the treatment of cancer. In this report parthenolide (PT), a sesquiterpene lactone of herbal remedies such as feverfew (Tanacetum parthenium) with NF‐κB inhibitory activity, markedly increased the degree of human leukaemia HL‐60 cell differentiation when simultaneously combined with 5 nM 1α,25‐dihydroxyvitamin D3 (1,25‐(OH)2D3). PT by itself did not induce HL‐60 cell differentiation.

Cytofluorometric analysis indicated that PT stimulated 1,25‐(OH)2D3‐induced differentiation of HL‐60 cells predominantly into monocytes.

Pretreatment of HL‐60 cells with PT before the 1,25‐(OH)2D3 addition also potentiated the 1,25‐(OH)2D3‐induced HL‐60 cell differentiation in both a dose‐ and a time‐dependent manner, in which the enhanced levels of cell differentiation closely correlated with the inhibitory levels of NF‐κB binding activity by PT.

In contrast, santonin, a sesquiterpene lactone without an inhibitory activity of NF‐κB binding to the κB sites, did not enhance the 1,25‐(OH)2D3‐induced HL‐60 cell differentiation.

In transfection experiments, PT enhanced 1,25‐(OH)2D3‐induced VDRE‐dependent promoter activity. Furthermore, PT restored 1,25‐(OH)2D3‐induced VDRE‐dependent promoter activity inhibited by TNF‐α, an activator of NF‐κB signalling pathway.

These results indicate that PT strongly potentiates the 1,25‐(OH)2D3‐induced HL‐60 cell differentiation into monocytes via the inhibition of NF‐κB activity and provide evidence that inhibition of NF‐κB activation can be a pre‐requisite to the efficient entry of promyelocytic leukaemia cells into a differentiation pathway.

British Journal of Pharmacology (2002) 135, 1235–1244; doi:10.1038/sj.bjp.0704573
Adenosine A2A receptors in portal hypertension: their role in the abnormal response to adenosine of the cranial mesenteric artery in rabbits
Authors: Villa de Brito M T , Canto A , Duarte Correia J H , Cunha R A , Marques M C
Published: January 2005

Adenosine is a regulator of mesenteric vasodilation involved in auto‐regulation and post‐prandial hyperemia, but the adenosine receptor subtype involved in this relaxant effect is poorly characterized. We have now pharmacologically characterized this receptor in rabbit mesenteric arteries and investigated how this adenosine receptor response changes in portal hypertensive animals since the adenosine response is decreased.

The closest non‐metabolisable adenosine analogue, 2‐chloroadenosine (CADO), the mixed A1/A2 receptor agonist, 5′‐ethylcarboxamidoadenosine (NECA), and the selective A2A receptor agonist, 2‐[4‐(2‐p‐carbonyethyl)phenylamino]‐5′‐N‐ethylcarboxamidoadenosine (CGS 21680) (1 pM – 1 mM) relaxed noradrenaline pre‐contracted arteries with a rank order of potency of CGS 21680 (EC50=20 nM)NECA (60 nM)>>CADO (640 nM).

The selective A2A receptor antagonist, 4‐(2‐[7‐amino‐2‐(2‐furyl)‐[1,2,4]‐triazolo[2,3‐a][1,3,5]‐triazin‐5‐ylamino]ethyl)phenol (ZM 241385, 100 nM), shifted to the right the CADO concentration‐response curve.

In portal hypertensive animals, there was mainly a decreased potency but also a decreased efficacy of all tested adenosine agonists compared to normal animals. Concomitantly, there was a decreased adenosine plasma level and a decreased binding density of [3H]‐CGS 21680 and [3H]‐ZM 241385 to mesenteric artery membranes from portal hypertensive compared to normal rabbits.

These results indicate that A2A receptor activation is required for the adenosine‐induced mesenteric relaxation and that the decreased density of A2A receptors may contribute to the decreased relaxation induced by adenosine of mesenteric arteries in portal hypertensive animals.

British Journal of Pharmacology (2002) 135, 1324–1330; doi:10.1038/sj.bjp.0704575
Systemic pre‐treatment with a group II mGlu agonist, LY379268, reduces hyperalgesia in vivo
Authors: Sharpe E F , Kingston A E , Lodge D , Monn J A , Headley P M
Published: January 2005

Previous studies investigating the role of metabotropic glutamate (mGlu) receptors in nociceptive processing have been hampered by the lack of systemically active, selective, ligands. This study investigates the possible analgesic and/or anti‐hyperalgesic properties of the most potent compound to date that has systemic agonist activity at group II mGlu receptors, LY379268.

In testing the drug in rats as an analgesic to acute noxious stimuli, LY379268 (in doses up to 3 mg kg−1 i.p.) did not affect withdrawal latencies to either mechanical or thermal stimulation.

However, when a 3 mg kg−1 dose was given prior to an intraplantar injection of carrageenan, the inflammatory hyperalgesia that developed was significantly delayed compared to saline pre‐treated controls, without affecting the inflammation of the paw. A similar dose of the mGlu‐inactive enantiomer, LY379267, was not anti‐hyperalgesic.

In a model of mouse tail withdrawal to warm water, LY379268 (12 mg kg−1 i.p.), given before a subcutaneous tail injection of capsaicin, reduced the subsequent neurogenic hyperalgesia.

Rota‐rod testing showed that the drug did not produce a motor impairment in rats at antihyperalgesic doses.

The results indicate that systemic activation of this group of mGlu receptors reduces both inflammatory and neurogenic thermal hyperalgesia.

British Journal of Pharmacology (2002) 135, 1255–1262; doi:10.1038/sj.bjp.0704583
Urocortin‐induced endothelium‐dependent relaxation of rat coronary artery: role of nitric oxide and K+ channels
Authors: Huang Yu , Chan Franky Leung , Lau Chi‐Wai , Tsang Suk‐Ying , He Guo‐Wei , Chen Zhen‐Yu , Yao Xiaoqiang
Published: January 2005

The mechanisms underlying the vasodilator response to urocortin are incompletely understood. The present study was designed to examine the role of endothelial nitric oxide and Ba2+‐sensitive K+ channels in the endothelium‐dependent component of urocortin‐induced relaxation in the rat left anterior descending coronary artery.

Urocortin induced both endothelium‐dependent and ‐independent relaxation with respective pD2 of 8.64±0.03 and 7.90±0.10. Removal of endothelium reduced the relaxing potency of urocortin. In rings pretreated with 10−4 M NG‐nitro‐L‐arginine methyl ester, 10−5 M methylene blue or 10−5 M ODQ, the urocortin‐induced relaxation was similar to that observed in endothelium‐denuded rings. L‐Arginine (5×10−4 M) antagonized the effect of NG‐nitro‐L‐arginine methyl ester.

The relaxant response to urocortin was reduced in endothelium‐intact rings preconstricted by 3.5×10−2 M K+ and abolished when extracellular K+ was raised to 5×10−2 M. Pretreatment with 10−4 M BaCl2 significantly inhibited urocortin‐induced relaxation. Combined treatment with 10−4 M BaCl2 plus 10−4 M NG‐nitro‐L‐arginine methyl ester did not cause further inhibition. In urocortin (10−8 M)‐relaxed rings, BaCl2 induced concentration‐dependent reversal in vessel tone. Tertiapin‐Q (10−6 M) also attenuated urocortin‐induced relaxation. In contrast, BaCl2 did not alter urocortin‐induced relaxation in endothelium‐denuded rings.

In endothelium‐denuded rings, hydroxylamine‐ and nitroprusside‐induced relaxation was inhibited by 10−4 M BaCl2, but not by 10−6 M tertiapin‐Q.

The endothelium of the coronary artery was moderately stained with the antiserum against urocortin.

Taken together, the present results indicate that the urocortin‐induced endothelium‐dependent relaxation of rat coronary arteries is likely attributable to endothelial nitric oxide and subsequent activation of Ba2+‐ or tertiapin‐Q‐sensitive K+ channels. The urocortin‐induced endothelium‐dependent relaxation appears to be mediated by cyclic GMP‐dependent mechanisms.

British Journal of Pharmacology (2002) 135, 1467–1476; doi:10.1038/sj.bjp.0704587
Kinetics of antagonist actions at rat P2X2/3 heteromeric receptors
Authors: Spelta Valeria , Jiang Lin‐Hua , Surprenant Annmarie , North R Alan
Published: January 2005

Currents through heteromeric P2X2/3 receptors were evoked by applying α,β‐methylene‐ATP to human embryonic kidney cells transfected with cDNAs encoding the P2X2 and P2X3 subunits. The concentration of α,β‐methylene‐ATP were 30 μM because higher concentrations can activate homomeric P2X2 receptors.

The kinetics of action of three structurally unrelated antagonists were studied; these were 2′, 3′‐O‐(2,4,6,trinitrophenyl)‐ATP (TNP‐ATP), pyridoxal‐5‐phosphate‐6‐azophenyl‐2′,4′‐disulphonate (PPADS) and suramin.

The association and dissociation rate constants were determined by pre‐applying the antagonist for various periods prior to the co‐application of agonist and antagonist, or by changing the solution from one containing only the agonist to one containing both agonist and antagonist.

The high affinity of TNP‐ATP for the P2X2/3 receptor (KD∼2 nM) results from fast binding (k+1∼100 μM−1 s−1) rather than slow unbinding (k−1∼0.3 s−1). For suramin (KD∼1 μM) the association rate constant (∼1 μM−1 s−1) was 100 times slower than that of TNP‐ATP but the dissociation rate constant was similar (k−1 ∼1 s−1). PPADS (KD∼0.1 μM) associated and dissociated some 100 – 10,000 times more slowly than the other antagonists.

British Journal of Pharmacology (2002) 135, 1524–1530; doi:10.1038/sj.bjp.0704591
Experimental model of escape phenomenon in hamsters and the effectiveness of YM‐53601 in the model
Authors: Ugawa Tohru , Kakuta Hirotoshi , Moritani Hiroshi , Shikama Hisataka
Published: January 2005

The aim of this study was to establish an experimental model of the escape phenomenon, in which plasma cholesterol, initially reduced by a 3‐hydroxy‐3‐methylglutaryl CoA (HMG‐CoA) reductase inhibitor such as pravastatin, increases again on long‐term administration. We also evaluated the efficacy of YM‐53601 ((E)‐2‐[2‐fluoro‐2‐ (quinuclidin‐3‐ylidene) ethoxy]‐9H‐carbazole monohydrochloride), a squalene synthase inhibitor, in this model.

Pravastatin inhibited cholesterol biosynthesis in hamster primary hepatocytes (IC50, 14 nM). After pre‐treatment with pravastatin, in contrast, almost no effect on cholesterol biosynthesis was seen.

In hamsters fed a high fat diet, 3 mg kg−1 pravastatin for 9 days decreased plasma non‐HDL cholesterol (total cholesterol – high density lipoprotein cholesterol) (P<0.01), but this effect was lost between 17 and 27 days of treatment, accompanied by an increase in HMG‐CoA reductase activity. No such increase in plasma non‐HDL cholesterol was seen with YM‐53601 at 30 mg kg−1 after 9 (P<0.001), 17 (P<0.01) or 27 (P<0.001) days of treatment. Replacement of pravastatin with YM‐53601 caused a decrease in plasma non‐HDL cholesterol by 53% (P<0.001) and in HMG‐CoA reductase activity.

This animal model thus satisfactorily replicates the escape phenomenon observed in humans and may therefore be useful in evaluation of lipid‐lowering agents, specifically comparison of HMG‐CoA reductase inhibitors. Further, YM‐53601 may be useful in the treatment of hypercholesterolemia without induction of the escape phenomenon.

British Journal of Pharmacology (2002) 135, 1572–1578; doi:10.1038/sj.bjp.0704595
Effects of FPL 64176 on Ca transients in voltage‐clamped rat venticular myocytes
Authors: Fan Jing‐Song , Palade Philip
Published: January 2005

The L‐type Ca channel agonist FPL 64176 increased the amplitude of both Ca currents and Ca transients elicited from isolated voltage clamped rat ventricular myocytes far more than it increased the rate of rise of the Ca transients. Consequently, the gain function relating the amplitude of peak Ca current to Ca transient rate of rise was greatly reduced at all potentials.

Furthermore, an increase in this gain function normally observed at negative potentials is abolished by FPL 64716.

Despite slowing the rate of decline of Ca transients, FPL 64176, at the concentration of 1 μM used throughout, had no direct effect on sarcoplasmic reticulum (SR) Ca uptake or release using isolated cardiac membranes.

Arguments based on results presented here and elsewhere suggest that decreased gain was not due to increased ryanodine receptor adaptation or inactivation, to decreased L‐type single channel current, to decreased SR Ca content, or to decreased synchronization of release. Decreased gain instead appears to reflect a form of decrease in coupling efficiency due either to differential effects of long openings on whole cell currents as opposed to the Ca release the long openings trigger or to some compensatory mechanism activated by the increased Ca trigger or resting free [Ca2+]i.

Abolition by FPL 64176 of the increased gain normally seen at negative potentials rendered it impossible to confirm or refute the claim that a single Ca ion suffices to activate ryanodine receptors.

British Journal of Pharmacology (2002) 135, 1495–1504; doi:10.1038/sj.bjp.0704598
Red wine polyphenols increase calcium in bovine aortic endothelial cells: a basis to elucidate signalling pathways leading to nitric oxide production
Authors: Martin Sophie , Andriambeloson Emile , Takeda Ken , Andriantsitohaina Ramaroson
Published: January 2005

The present study investigates the mechanisms by which polyphenolic compounds from red wine elicit Ca2+ mobilization in bovine aortic endothelial cells (BAECs). Two polyphenol‐containing red wine extracts, red wine polyphenolic compounds (RWPC) and Provinols™, and delphinidin, an anthocyanin were used.

RWPC stimulated a Ca2+‐dependent release of nitric oxide (NO) from BAECs accounting for the relaxation of endothelium‐denuded rat aortic rings as shown by cascade bioassay.

RWPC, Provinols™ and delphinidin increased cytosolic free calcium ([Ca2+]i), by releasing Ca2+ from intracellular stores and by increasing Ca2+ entry.

The RWPC‐induced increase in [Ca2+]i was decreased by exposure to ryanodine (30 μM), whereas Provinols™ and delphinidin‐induced increases in [Ca2+]i were decreased by bradykinin (0.1 μM) and thapsigargin (1 μM) pre‐treatment.

RWPC, Provinols™ and delphinidin‐induced increases in [Ca2+]i were sensitive to inhibitors of phospholipase C (neomycin, 3 mM; U73122, 3 μM) and tyrosine kinase (herbimycin A, 1 μM).

RWPC, Provinols™ and delphinidin induced herbimycin A (1 μM)‐sensitive tyrosine phosphorylation of several intracellular proteins.

Provinols™ released Ca2+ via both a cholera (CTX) and pertussis toxins (PTX)‐sensitive pathway, whereas delphinidin released Ca2+ only via a PTX‐sensitive mechanism.

Our data contribute in defining the mechanisms of endothelial NO production caused by wine polyphenols including the increase in [Ca2+]i and the activation of tyrosine kinases. Furthermore, RWPC, Provinols™ and delphinidin display differences in the process leading to [Ca2+]i increases in endothelial cells illustrating multiple cellular targets of natural dietary polyphenolic compounds.

British Journal of Pharmacology (2002) 135, 1579–1587; doi:10.1038/sj.bjp.0704603
Neuropeptide Y, Y1, Y2 and Y4 receptors mediate Y agonist responses in isolated human colon mucosa
Authors: Cox Helen M , Tough Iain R
Published: January 2005

The aim of this study was to provide a pharmacological characterization of the Y receptor types responsible for neuropeptide Y (NPY), peptide YY (PYY) and pancreatic polypeptide (PP) effects upon electrogenic ion transport in isolated human colonic mucosa.

Preparations of descending colon were voltage‐clamped at 0 mV in Ussing chambers and changes in short‐circuit current (Isc) continuously recorded. Basolateral PYY, NPY, human PP (hPP), PYY(3 – 36), [Leu31, Pro34]PYY (Pro34PYY) and [Leu31, Pro34]‐NPY (Pro34NPY) all reduced basal Isc in untreated colon. Of all the Y agonists tested PYY(3 – 36) responses were most sensitive to tetrodotoxin (TTX) pretreatment, indicating that Y2‐receptors are located on intrinsic neurones as well as epithelia in this tissue.

The EC50 values for Pro34PYY, PYY(3 – 36) and hPP were 9.7 nM (4.0 – 23.5), 11.4 nM (7.6 – 17.0) and 14.5 nM (10.2 – 20.5) and response curves exhibited similar efficacies. The novel Y5 agonist [Ala31, Aib32]‐NPY had no effect at 100 nM.

Y1 receptor antagonists, BIBP3226 and BIBO3304 both increased basal Isc levels per se and inhibited subsequent PYY and Pro34PYY but not hPP or PYY(3 – 36) responses. The Y2 antagonist, BIIE0246 also raised basal Isc levels and attenuated subsequent PYY(3 – 36) but not Pro34PYY or hPP responses.

We conclude that Y1 and Y2 receptor‐mediated inhibitory tone exists in human colon mucosa. PYY and NPY exert their effects via both Y1 and Y2 receptors, but the insensitivity of hPP responses to either Y1 or Y2 antagonism, or to TTX, indicates that Y4 receptors are involved and that they are predominantly post‐junctional in human colon.

British Journal of Pharmacology (2001) 135, 1505–1512; doi:10.1038/sj.bjp.0704604
A comparison of the efficacy of carbamazepine and the novel anti‐epileptic drug levetiracetam in the tetanus toxin model of focal complex partial epilepsy
Authors: Doheny H C , Whittington M A , Jefferys J G R , Patsalos P N
Published: January 2005

The tetanus toxin seizure model, which is associated with spontaneous and intermittent generalized and non‐generalized seizures, is considered to reflect human complex partial epilepsy. The purpose of the present study was to investigate and compare the anticonvulsant effects of carbamazepine with that of levetiracetam, a new anti‐epileptic drug in this model.

One μl of tetanus toxin solution (containing 12 mLD50 μl−1of tetanus toxin) was placed stereotactically into the rat left hippocampus resulting in generalized and non‐generalized seizures. Carbamazepine (4 mg kg−1 h−1) and levetiracetam (8 and 16 mg kg−1 h−1) were administered during a 7 day periodviaan osmotic minipump which was placed in the peritoneal cavity.

Carbamazepine (4 mg kg−1 h−1) exhibited no significant anticonvulsant effect, compared to control, when the entire 7 day study period was evaluated but the reduction in generalized seizures was greater (35.5%) than that for non‐generalized seizures (12.6%). However, during the first 2 days of carbamazepine administration a significant reduction in both generalized seizure frequency (90%) and duration (25%) was observed. Non‐generalized seizures were unaffected. This time‐dependent anticonvulsant effect exactly paralleled the central (CSF) and peripheral (serum) kinetics of carbamazepine in that steady‐state concentrations declined over time, with the highest concentrations achieved during the first 2 days. Also there was a significant 27.3% reduction in duration of generalized seizures during the 7 day study period (P=0.0001).

Levetiracetam administration (8 and 16 mg kg−1 h−1) was associated with a dose‐dependent reduction in the frequency of both generalized (39 v 57%) and non‐generalized (36 v 41%) seizures. However, seizure suppression was more substantial for generalized seizures. Also a significant dose‐dependent reduction in overall generalized seizure duration was observed.

These data provide experimental evidence for the clinical efficacy of levetiracetam for the management of patients with complex partial seizures. Furthermore, levetiracetam probably does not act by preventing ictogenesisper sebut acts to reduce seizure severity and seizure generalization.

British Journal of Pharmacology(2002)135, 1425–1434; doi:10.1038/sj.bjp.0704606