bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence in locomotion test for the functional heterogeneity of ORL‐1 receptors
Authors: Kuzmin Alexander , Sandin Johan , Terenius Lars , Ögren Sven Ove 
Published: January 2004

The ORL1 agonists nociceptin and Ro 64‐6198 were compared in their ability to modify spontaneous locomotor activity in male NMRI mice not habituated to the test environment.
Higher doses of nociceptin (>5 nmol i.c.v.) reduced whereas lower doses (<1 nmol i.c.v.) stimulated locomotor activity. Both effects were blocked by the putative ORL1 antagonists [NPhe1]nociceptin(1–13)NH2 (10 nmol i.c.v.) and UFP101 (10 nmol, i.c.v.). The effects were also blocked by naloxone benzoylhydrazone (1 mg kg−1 s.c.), but not by the nonselective opioid antagonist naloxone (1 mg kg−1 s.c.).
In contrast to nociceptin, the synthetic ORL1 agonist Ro 64‐6198 (0.01–1.0 mg kg−1 i.p.) produced monophasic inhibition of locomotor activity, which was insensitive to the treatment with [NPhe1]nociceptin(1–13)NH2 or naloxone benzoylhydrazone. Treatment with UFP101 abolished the locomotor inhibition induced by Ro 64‐6198 (1.0 mg kg−1), whereas naloxone (1.0 mg kg−1, s.c.) further increased the locomotor‐inhibitory effects.
Naloxone benzoylhydrazone (0.3; 1.0 and 3.0 mg kg−1 s.c.) increased locomotor activity, although the effect was statistically significant only with the highest dose used.
Pretreatment with the tyrosine hydroxylase inhibitor H44‐68 totally eliminated the motor‐stimulatory effects of low doses of nociceptin, probably via dopamine depletion.
The results suggest that nociceptin stimulates locomotor activity at low doses if dopamine activity is intact. High doses of nociceptin and all the tested doses of Ro 64‐6198 seem to interact with a functionally different subset of ORL1 receptors. In addition, the effects of Ro 64‐6198 are modulated by tonic opioid receptor activity.

British Journal of Pharmacology (2004) 141, 132–140. doi:10.1038/sj.bjp.0705583
Phospholipase C, but not InsP3 or DAG, ‐dependent activation of the muscarinic receptor‐operated cation current in guinea‐pig ileal smooth muscle cells
Authors: Zholos Alexander V , Tsytsyura Yaroslav D , Gordienko Dmitri V , Tsvilovskyy Vladimir V , Bolton Tom B 
Published: January 2004

In visceral smooth muscles, both M2 and M3 muscarinic receptor subtypes are found, and produce two major metabolic effects: adenylyl cyclase inhibition and PLCβ activation. Thus, we studied their relevance for muscarinic cationic current (mICAT) generation, which underlies cholinergic excitation. Experiments were performed on single guinea‐pig ileal cells using patch‐clamp recording techniques under conditions of weakly buffered [Ca2+]i (either using 50 μM EGTA or 50–100 μM fluo‐3 for confocal fluorescence imaging) or with [Ca2+]i ‘clamped’ at 100 nM using 10 mM BAPTA/CaCl2 mixture.
Using a cAMP‐elevating agent (1 μM isoproterenol) or a membrane‐permeable cAMP analog (10 μM 8‐Br‐cAMP), we found no evidence for mICAT modulation through a cAMP/PKA pathway.
With low [Ca2+]i buffering, the PLC blocker U‐73122 at 2.5 μM almost abolished mICAT, in some cases without any significant effect on [Ca2+]i. When [Ca2+]i was buffered at 100 nM, U‐73122 reduced both carbachol‐ and GTPγS‐induced mICAT maximal conductances (IC50=0.5–0.6 μM) and shifted their activation curves positively.
U‐73343, a weak PLC blocker, had no effect on GTPγS‐induced mICAT, but weakly inhibited carbachol‐induced current, possibly by competitively inhibiting muscarinic receptors, since the inhibition could be prevented by increasing the carbachol concentration to 1 mM. Aristolochic acid and D‐609, which inhibit PLA2 and phosphatidylcholine‐specific PLC, respectively, had no or very small effects on mICAT, suggesting that these enzymes were not involved.
InsP3 (1 μM) in the pipette or OAG (20 μM) applied externally had no effect on mICAT or its inhibition by U‐73122. Ca2+ store depletion (evoked by InsP3, or by combined cyclopiazonic acid, ryanodine and caffeine treatment) did not induce any significant current, and had no effect on mICAT in response to carbachol when [Ca2+]i was strongly buffered to 100 nM.
It is concluded that phosphatidylinositol‐specific PLC modulates mICAT via Ca2+ release, but also does so independently of InsP3, DAG, Ca2+ store depletion or a rise of [Ca2+]i. Our present results explain the previously established ‘permissive’ role of the M3 receptor subtype in mICAT generation, and provide a new insight into the molecular mechanisms underlying the shifts of the cationic conductance activation curve.

British Journal of Pharmacology (2004) 141, 23–36. doi:10.1038/sj.bjp.0705584
Peroxisome proliferator activated‐receptor agonism and left ventricular remodeling in mice with chronic myocardial infarction
Authors: Frantz Stefan , Hu Kai , Widder Julian , Bayer Barbara , Witzel Catharina Clara , Schmidt Isabel , Galuppo Paolo , Strotmann Jörg , Ertl Georg , Bauersachs Johann 
Published: January 2004

Peroxisome proliferator activated receptor γ (PPARγ) has been implicated in several cellular pathways assumed to beneficially affect heart failure progression. In contrast, population‐based studies demonstrate an increased incidence of heart failure in patients treated with PPARγ agonists. Therefore, we examined the effect of pioglitazone, a PPARγ agonist, on chronic left ventricular remodeling after experimental myocardial infarction (MI) in mice.
Mice were treated with placebo or pioglitazone (20 mg kg−1 by gavage) from week 1 to week 6 after ligation of the left anterior descending artery. Serial transthoracic echocardiography was performed at weeks 1, 3, and 6.
Over 6 weeks, there was no difference in mortality (placebo 12%, pioglitazone 10%). Echocardiography showed significant left ventricular dilatation in animals with MI (week 6, end‐systolic area, placebo sham 9.6±1.3 vs placebo MI 14.4±2.5 mm2). However, there was no difference between the placebo and pioglitazone groups (week 6, end‐systolic area, pioglitazone MI 14.8±2.9 mm2, P=NS vs placebo).
Moreover, there were no changes in metabolic parameters, inflammation, and collagen deposition. Endothelial function in the aorta was not changed by PPARγ activation.
In conclusion, PPARγ activation did not adversely affect left ventricular remodeling and survival in mice with chronic MI. However, we were also not able to identify a protective effect of pioglitazone.

British Journal of Pharmacology (2004) 141, 9–14. doi:10.1038/sj.bjp.0705585
Ligands of the peroxisome proliferator‐activated receptor‐γ and heart failure
Authors: Thiemermann C 
Published: January 2004

Peroxisome proliferator‐activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand‐activated transcription factors that are related to retinoid, steroid and thyroid hormone receptors. The PPAR subfamily comprises of three members, PPAR‐α, PPAR‐β and PPAR‐γ. There is good evidence that ligands of PPAR‐γ, including certain thiazolinediones, reduce myocardial tissue injury and infarct size. The use of PPAR‐γ agonists in the treatment of heart failure is, however, controversial.British Journal of Pharmacology (2004) 141, 1–3. doi:10.1038/sj.bjp.0705586
Repeated treatment with the synthetic cannabinoid WIN 55,212‐2 reduces both hyperalgesia and production of pronociceptive mediators in a rat model of neuropathic pain
Authors: Costa B , Colleoni M , Conti S , Trovato A E , Bianchi M , Sotgiu M L , Giagnoni G 
Published: January 2004

The antinociceptive properties of cannabinoids in persistent pain are not fully elucidated. We investigated the effect of repeated treatment with the synthetic cannabinoid receptor agonist WIN 55,212‐2 on the neuropathic pain induced in rats by chronic constriction of the sciatic nerve. WIN 55,212‐2 administered daily throughout the development of neuropathy reversed the hyperalgesia, at a dose (0.1 mg kg−1, s.c.) that had no effect on the nociceptive responses of either paw contralateral to the sciatic ligation or of animals subjected to sham surgery. At 14 days after injury, the levels of mediators known to be involved in neuropathic pain, such as prostaglandin E2, NO and the neuronal NOS, were increased. Repeated treatment with WIN 55,212‐2 abolished these increases. In the light of the current clinical need for neuropathic pain treatments, these findings indicate that cannabinoid agonists, at doses devoid of psychoactive effects, could constitute important compounds for the development of new analgesics.British Journal of Pharmacology (2004) 141, 4–8. doi:10.1038/sj.bjp.0705587
Adenine nucleotides inhibit recombinant N‐type calcium channels via G protein‐coupled mechanisms in HEK 293 cells; involvement of the P2Y13 receptor‐type
Authors: Wirkner Kerstin , Schweigel Joana , Gerevich Zoltan , Franke Heike , Allgaier Clemens , Barsoumian Edward Leon , Draheim Henning , Illes Peter 
Published: January 2004

N‐type Ca2+ channel modulation by an endogenous P2Y receptor was investigated by the whole‐cell patch‐clamp method in HEK 293 cells transfected with the functional rabbit N‐type calcium channel.
The current responses (ICa(N)) to depolarizing voltage steps were depressed by ATP in a concentration‐dependent manner. Inclusion of either guanosine 5′‐O‐(3‐thiodiphosphate) or pertussis toxin into the pipette solution as well as a strongly depolarizing prepulse abolished the inhibitory action of ATP.
In order to identify the P2Y receptor subtype responsible for this effect, several preferential agonists and antagonists were studied. Whereas the concentration–response curves of ADP and adenosine 5′‐O‐(2‐thiodiphosphate) indicated a higher potency of these agonists than that of ATP, α,β‐methylene ATP, UTP and UDP were considerably less active. The effect of ATP was abolished by the P2Y receptor antagonists suramin and N6‐(2‐methylthioethyl)‐2‐(3,3,3‐trifluoropropylthio)‐β,γ‐dichloromethylene‐ATP, but not by pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulfonic acid, 2′deoxy‐N6‐methyladenosine‐3′,5′‐diphosphate or 2‐methylthio AMP.
Using reverse transcription and polymerase chain reaction, mRNA for the P2Y1, P2Y4, P2Y6, P2Y11 and P2Y13 receptor subtypes, but not the P2Y2, and P2Y12 subtypes, was detected in HEK 293 cells.
Immunocytochemistry confirmed the presence of P2Y1, and to a minor extent that of P2Y4, but not of P2Y2 receptors.
Hence, it is tempting to speculate that P2Y13 receptors may inhibit N‐type Ca2+ channels via the βγ subunits of the activated Gi protein.

British Journal of Pharmacology (2004) 141, 141–151. doi:10.1038/sj.bjp.0705588
A truncated form of CKβ8‐1 is a potent agonist for human formyl peptide‐receptor‐like 1 receptor
Authors: Elagoz Aram , Henderson Duncan , Babu Poda Suresh , Salter Sylvia , Grahames Caroline , Bowers Lorna , Roy Marie‐Odile , Laplante Patricia , Grazzini Eric , Ahmad Sultan , Lembo Paola M C 
Published: January 2004

Human formyl peptide‐receptor‐like‐1 (FPRL‐1) is a promiscuous G protein‐coupled receptor (GPCR), and belongs to a chemoattractant receptor family protein. This receptor has been reported to interact with various host‐derived peptides and lipids involved in inflammatory responses. We described here, a novel role for FPRL‐1 as a high‐affinity β‐chemokine receptor for an N‐terminally truncated form of the CKβ8 (CCL23/MPIF‐1) splice variant CKβ8‐1 (22–137 aa).
RT‐PCR analysis of mRNA derived from human tissues and cells revealed a predominant expression of FPRL‐1 in inflammatory cells, particularly in neutrophils.
Intracellular calcium mobilisation assay, used as screening tool, in recombinant Chinese hamster ovary (CHO‐K1) and human embryonic kidney (HEK293s) cells coexpressing FPRL‐1 and Gα16, demonstrated FPRL‐1 is a functional high‐affinity receptor for CKβ8‐1 (46–137 aa, sCKβ8‐1), with pEC50 values of 9.13 and 8.85, respectively.
The FPRL‐1 activation in CHO‐K1 cells is mediated by Gαi/Gαo proteins, as assessed by pertussis toxin sensitivity and inhibition of forskolin‐induced cyclic AMP accumulation.
Binding experiments were performed with a radio‐iodinated synthetic peptide, [125‐I]‐WKYMVm, a known potent FPRL‐1 agonist. CHO‐K1 cell membranes expressing FPRL‐1 bound [125‐I]‐WKYMVm with a Kd value of 9.34. Many known FPRL‐1 agonists were tested and sCKβ8‐1 was the most effective nonsynthetic ligand in displacing the radiolabelled agonist, with a pIC50 of 7.97.
The functional significance of sCKβ8‐1 interaction with FPRL‐1 was further demonstrated by the activation of polymorphonuclear leukocytes (PMNs) calcium mobilisation and chemotaxis. These interactions were shown to be via FPRL‐1 by specific blockade of PMNs activation in the presence of an FPRL‐1 antibody.

British Journal of Pharmacology (2004) 141, 37–46. doi:10.1038/sj.bjp.0705592
Changes in rectal temperature and ECoG spectral power of sensorimotor cortex elicited in conscious rabbits by i.c.v. injection of GABA, GABAA and GABAB agonists and antagonists
Authors: Frosini Maria , Valoti Massimo , Sgaragli Giampietro 
Published: January 2004

In order to ascertain whether both GABAA and GABAB, or only GABAB receptors, directly modulate thermoregulation in conscious rabbits, GABAA/GABAB agonist and antagonist agents were injected intracerebroventricularly in conscious rabbits while monitoring changes in rectal temperature (RT), gross motor behaviour (GMB) and electrocorticogram (ECoG) power spectra (ps) from sensorimotor cortices.
GABA (48 μmol), nipecotic acid (50 nmol), THIP (60 nmol), muscimol (18 nmol) and baclofen (8 nmol) induced hypothermia (−ΔRTmax values of 1.70±0.1, 1.4±0.2, 1.0±0.4, 1.1±0.2 and 1.6±0.3°C, respectively), accompanied by inhibition of GMB and ECoG synchronization. THIP increased ps at δ frequency band (1.1−3.3 Hz), while GABA, nipecotic acid, muscimol and baclofen did the same at both δ and θ (4.6−6.5 Hz) frequency bands. ECoG ps changes were concomitant or even preceded hypothermia.
Bicuculline (1.8 nmol) induced hyperthermia (ΔRTmax 1.2±0.5°C) and slight excitation of GMB, while CGP35348 (1.2 μmol) did not affect RT nor GMB. Both compounds did not affect ECoG ps.
Bicuculline potentiated muscimol‐induced hypothermia, inhibition of GMB and synchronization of ECoG, while CGP35348 fully antagonized these effects.
In conclusion, the present results, while confirming the prevailing role of GABAB, also outline a direct involvement of GABAA receptors in the central mechanisms of thermoregulation. Ascending inhibition towards discrete cortical areas controlling muscular activity and thermogenesis may result from GABA receptor activation in neurones proximal to the ventricles, thus contributing to hypothermia, although hypothermia‐induced reduction of neuronal activity of these cortical areas cannot be ruled out.

British Journal of Pharmacology (2004) 141, 152–162. doi:10.1038/sj.bjp.0705593
An improved model for the binding of lidocaine and structurally related local anaesthetics to fast‐inactivated voltage‐operated sodium channels, showing evidence of cooperativity
Authors: Leuwer Martin , Haeseler Gertrud , Hecker Hartmut , Bufler Johannes , Dengler Reinhard , Aronson Jeffrey K 
Published: January 2004

The interaction of lidocaine‐like local anaesthetics with voltage‐operated sodium channels is traditionally assumed to be characterized by tighter binding of the drugs to depolarized channels. As inactivated and drug‐bound channels are both unavailable on depolarization, an indirect approach is required to yield estimates for the dissociation constants from channels in inactivated states. The established model, originally described by Bean et al., describes the difference in affinity between resting and inactivated states in terms of the concentration dependence of the voltage shift in the availability curve. We have tested the hypothesis that this model, which assumes a simple Langmuir relationship, could be improved by introducing a Hill‐type exponent, which would take into account potential sources of cooperativity.
Steady‐state block by lidocaine was studied in heterologously (HEK 293) expressed human skeletal muscle sodium channels and compared with experimental data previously obtained for 2,6‐dimethylphenol, 3,5‐dimethyl‐4‐chlorophenol, and 4‐chlorophenol. Cells were clamped to membrane potentials from −150 to −5 mV, and a subsequent test pulse was used to assess the number of channels available to open.
All compounds shifted the voltage dependence of channel availability in the direction of negative prepulse potentials. Prediction of the concentration dependence of the voltage shift in the availability curve was improved by the modified model, as shown by a marked reduction in the residual sum of squares.
For all compounds, the Hill‐type exponent was significantly greater than one. These results could be interpreted in the light of the contemporary hypothesis that lidocaine functions as an allosteric gating effector to enhance sodium channel inactivation by strengthening the latch mechanism of inactivation, which is considered to be a particle‐binding process allosterically coupled to activation. Alternatively, they could be interpreted by postulating additional binding sites for lidocaine on fast‐inactivated sodium channels.

British Journal of Pharmacology (2004) 141, 47–54. doi:10.1038/sj.bjp.0705594
G‐protein receptor kinase 3 (GRK3) influences opioid analgesic tolerance but not opioid withdrawal
Authors: Terman Gregory W , Jin Wenzhen , Cheong Young‐Pyo , Lowe Janet , Caron Marc G , Lefkowitz Robert J , Chavkin Charles 
Published: January 2004

Tolerance to opioids frequently follows repeated drug administration and affects the clinical utility of these analgesics. Studies in simple cellular systems have demonstrated that prolonged activation of opioid receptors produces homologous receptor desensitization by G‐protein receptor kinase mediated receptor phosphorylation and subsequent β‐arrestin binding. To define the role of this regulatory mechanism in the control of the electrophysiological and behavioral responses to opioids, we used mice having a targeted disruption of the G‐protein receptor kinase 3 (GRK3) gene.
Mice lacking GRK3 did not differ from wild‐type littermates neither in their response latencies to noxious stimuli on the hot‐plate test nor in their acute antinociceptive responses to fentanyl or morphine.
Tolerance to the electrophysiological response to the opioid fentanyl, measured in vitro in the hippocampus, was blocked by GRK3 deletion. In addition, tolerance to the antinociceptive effects of fentanyl was significantly reduced in GRK3 knockouts compared to wild‐type littermate controls.
Tolerance to the antinociceptive effects of morphine was not affected by GRK3 deletion although morphine tolerance in hippocampal slices from GRK3 knockout mice was significantly inhibited. Tolerance developed more slowly in vitro to morphine than fentanyl supporting previous work in in vitro systems showing a correlation between agonist efficacy and GRK3‐mediated desensitization.
The results of these studies suggest that GRK3‐mediated mechanisms are important components of both electrophysiologic and behavioral opioid tolerance. Fentanyl, a high efficacy opioid, more effectively produced GRK3‐dependent effects than morphine, a low efficacy agonist.

British Journal of Pharmacology (2004) 141, 55–64. doi:10.1038/sj.bjp.0705595
A nitric oxide (NO)‐releasing derivative of gabapentin, NCX 8001, alleviates neuropathic pain‐like behavior after spinal cord and peripheral nerve injury
Authors: Wu Wei‐Ping , Hao Jing‐Xia , Ongini Ennio , Impagnatiello Francesco , Presotto Cristina , Wiesenfeld‐Hallin Zsuzsanna , Xu Xiao‐Jun 
Published: January 2004

Nitric oxide (NO) participates, at least in part, to the establishment and maintenance of pain after nerve injury. Therefore, drugs that target the NO/cGMP signaling pathway are of interest for the treatment of human neuropathic pain. Various compounds endowed with NO‐releasing properties modulate the expression and function of inducible nitric oxide synthase (iNOS), the key enzyme responsible for sustained NO production under pathological conditions including neuropathic pain.
With this background, we synthesized a new chemical entity, [1‐(aminomethyl)cyclohexane acetic acid 3‐(nitroxymethyl)phenyl ester] NCX8001, which has a NO‐releasing moiety bound to gabapentin, a drug currently used for the clinical management of neuropathic pain. We examined the pharmacological profile of this drug with respect to its NO‐releasing properties in vitro as well as to its efficacy in treating neuropathic pain conditions (allodynia) consequent to experimental sciatic nerve or spinal cord injuries.
NCX8001 (1–30 μM) released physiologically relevant concentrations of NO as it induced a concentration‐dependent activation of soluble guanylyl cyclase (EC50=5.6 μM) and produced consistent vasorelaxant effects in noradrenaline‐precontracted rabbit aortic rings (IC50=1.4 μM).
NCX8001, but not gabapentin, counteracted in a concentration‐dependent fashion lipopolysaccharide‐induced overexpression and function of iNOS in RAW264.7 macrophages cell line. Furthermore, NCX8001 also inhibited the release of tumor necrosis factor alpha (TNFα) from stimulated RAW264.7 cells.
NCX8001 (28–280 μmol kg−1, i.p.) reduced the allodynic responses of spinal cord injured rats in a dose‐dependent fashion while lacking sedative or motor effects. In contrast, gabapentin (170–580 μmol kg−1, i.p.) resulted less effective and elicited marked side effects.
NCX8001 alleviated the allodynia‐like responses of rats to innocuous mechanical or cold stimulation following lesion of the sciatic nerve. This effect was not shared by equimolar doses of gabapentin.
Potentially due to the slow releasing kinetics of NO, NCX8001 alleviated pain‐like behaviors in two rat models of neuropathic pain in a fashion that is superior to its parent counterpart gabapentin. This new gabapentin derivative, whose mechanism deserves to be explored further, offers new hopes to the treatment of human neuropathic pain.

British Journal of Pharmacology (2004) 141, 65–74. doi:10.1038/sj.bjp.0705596
Paradoxical early glucocorticoid induction of stem cell factor (SCF) expression in inflammatory conditions
Authors: Da Silva Carla Alexandra , Kassel Olivier , Lebouquin Renaud , Lacroix Emmanuel Jean , Frossard Nelly 
Published: January 2004

Stem cell factor (SCF) is a major growth factor for mast cells, promoting their differentiation and chemotaxis. Its expression is regulated by glucocorticoids in inflammatory conditions, showing an early increased protein expression, before the expected anti‐inflammatory decrease (Da Silva et al., Br. J. Pharmacol. 2002:135,1634).
We here evaluated the early kinetic of SCF expression regulated by interleukin (IL)‐1β, budesonide and the combination of both in human lung fibroblasts in culture.
Budesonide potentiated the IL‐1β‐enhanced expression of SCF mRNA (+103%) and protein (+98%) very shortly after treatment (at 30 min and 1 h, respectively). A gentle downregulation followed. This potentiating effect of budesonide was related to increased SCF mRNA stability and SCF gene transcription.
Deletion of a κB‐like site that we identified in the first intron of the SCF gene, in a luciferase reporter system, abolished the potentiation by budesonide, as well as the effect of IL‐1β alone, as compared to the wild‐type construction activity.
All budesonide‐induced effects were glucocorticoid‐receptor dependent, since they were reproduced by dexamethasone and blocked by RU486.
IL‐1β+budesonide did not affect the relative expression of the soluble and membrane‐bound forms of SCF.
In conclusion, our results clearly show that glucocorticoids act very early to adversely increase the expression of SCF mRNA and protein in the inflammatory conditions created by IL‐1β, and that this effect involves increased mRNA stability and increased gene expression through activation of the NF‐κB‐like responsive element.

British Journal of Pharmacology (2004) 141, 75–84. doi:10.1038/sj.bjp.0705598