bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the P2 receptors on the human umbilical vein endothelial cell line ECV304
Authors: Conant Alan R , Fisher Michael J , McLennan Alexander G , Simpson Alec W M 
Published: January 2005

To characterize the P2 receptors present on the human umbilical vein endothelial‐derived cell line, ECV304, cytosolic Ca2+, ([Ca2+]c), responses were recorded in single cells and in cell suspensions to a series of nucleotides and nucleotide agonists.
Concentration response curves were obtained in fura‐2‐loaded ECV304 cell suspensions, with EC50 values of 4.2 μM for ATP, 2.5 μM for UTP and 14 μM for adenosine‐5′‐O‐(3‐thio)triphosphate (ATPγS). EC50 values for 2‐methylthioATP, ADP, adenosine‐5′‐O‐(2‐thio)diphosphate (ADPβS) and AMP were 0.5 μM, 3.5 μM, 15 μM and 4.7 μM respectively, but maximal [Ca2+]c responses were less than those produced by a maximal addition of ATP/UTP. ECV304 cells were unresponsive to UDP and β,γ,methyleneATP.
Cross‐desensitization studies on ECV304 cells suggested that ATP and UTP recognized the same receptor. However, ADP recognized a receptor distinct from the UTP‐sensitive receptor and AMP recognized a third distinct receptor.
ECV304 [Ca2+]c responses to 2‐methylthioATP were inhibited in the presence of 30 μM pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS), whereas [Ca2+]c responses to UTP were unaffected by this treatment.
ECV304 cells responded to the diadenosine polyphosphate Ap3A with rises in [Ca2+]c. Apparent responses to Ap4A, Ap5A and Ap6A, were shown to be due to a minor nucleotide contaminant that could be removed by pre‐treatment of the diadenosine samples with either alkaline phosphatase or apyrase.
ECV304 cells display a pharmacology consistent with the presence of at least two P2 receptors; a P2Y2 receptor insensitive to the diadenosine polyphosphates and a P2Y1 receptor sensitive to Ap3A. In addition, ECV304 cells respond to AMP with increases in [Ca2+]c via an as yet uncharacterized receptor.

British Journal of Pharmacology (1998) 125, 357–364; doi:10.1038/sj.bjp.0702082
LF 16.0335, a novel potent and selective nonpeptide antagonist of the human bradykinin B2 receptor
Authors: Pruneau Didier , Luccarini Jean‐Michel , Fouchet Chantal , Defrêne Evelyne , Franck Rose‐Marie , Loillier Bruno , Duclos Hervé , Robert Claude , Cremers Béatrice , Bélichard Pierre , Paquet Jean‐Luc 
Published: January 2005

In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1‐[[3‐[(2,4‐dimethylquinolin‐8‐yl)oxymethyl]‐2,4‐dichloro‐phenyl]sulphonyl] ‐2(S) ‐ [[4 ‐[4‐(aminoiminomethyl)phenylcarbonyl]piperazin‐1‐yl]carbonyl]pyrrolidine), a novel and potent nonpeptide antagonist of the human bradykinin (BK) B2 receptor.
LF 16.0335 displaced [3H]‐BK binding to membrane preparations from CHO cells expressing the cloned human B2 receptor, INT 407 cells and human umbilical vein with Ki values of 0.84±0.39 nM, 1.26±0.68 nM and 2.34±0.36 nM, respectively.
In saturation binding studies performed in INT 407 cell membranes in the presence or absence of LF 16.0335, Bmax values of [3H]‐BK were not significantly changed suggesting that LF 16.0335 behaves as a competitive antagonist.
LF 16.0335 had no affinity for the cloned human kinin B1 receptor stably expressed in 293 cells. In addition, this compound at 1 μM did not significantly bind to a range of 40 different membrane receptors and eight ion channels except muscarinic M2 and M1 receptors for which an IC50 value of 0.9 and 1 μM was obtained.
BK stimulates in a concentration‐dependent manner phosphoinositosides (IPs) production in cultured INT 407 cells. Concentration‐response‐curves to BK were shifted to the right in the presence of LF 16.0335 (0.1 μM) without reduction of the maximum. LF 16.0335 inhibited the concentration‐contraction curve to BK in the human umbilical vein giving a pA2 value of 8.30±0.30 with a Schild plot slope that was not different from unity.
These results demonstrate that LF 16.0335 is a potent, selective and competitive antagonist of the human bradykinin B2 receptor.

British Journal of Pharmacology (1998) 125, 365–372; doi:10.1038/sj.bjp.0702083
Modulation of the vagal bradycardia evoked by stimulation of upper airway receptors by central 5‐HT1 receptors in anaesthetized rabbits
Authors: Dando Simon B , Skinner Matthew R , Jordan David , Ramage Andrew G 
Published: January 2005

The effects of central application of 5‐HT1A and 5‐HT1B/1D receptor ligands on the reflex bradycardia, apnoea, renal sympathoexcitation and pressor response evoked by stimulating upper airway receptors with smoke in atenolol‐pretreated anaesthetized rabbits were studied.
Intracisternal administration of the 5‐HT1A receptor antagonists WAY‐100635 (100 μg kg−1) and (−)pindolol (100 μg kg−1) significantly reduced the smoke‐induced bradycardia, attenuated the pressor response and in the case of (−)pindolol, sympathetic nerve activity. The same dose of WAY‐100635 i.v. was without effect.
Buspirone (200 μg kg−1, i.c.) potentiated the reflex bradycardia. This action was prevented if the animals were pretreated with WAY‐100635 (100 μg kg−1, i.v.)
(+)8‐OH‐DPAT (25 μg kg−1, i.c.) attenuated the evoked bradycardia, pressor response, apnoea and renal sympathoexcitation. The attenuation of the apnoea and renal sympathoexcitation, but not the bradycardia or pressor response was prevented in animals pretreated with WAY‐100635 (100 μg kg−1, i.v.). The attenuation of the reflex bradycardia and the reduction in the renal sympathoexcitation were reduced by pretreatment with the 5‐HT1B/1D receptor antagonist GR127935 (100 μg kg−1, i.v.).
In WAY‐100635 (100 μg kg−1, i.v.) pretreated animals, sumatriptan (a 5‐HT1B/1D receptor agonist) reduced the reflex bradycardia and the pressor response. The 5‐HT1B/1D receptor antagonist GR127935 (20 μg kg−1, i.c. or 100 μg kg−1, i.v.) had no effect on the reflex responses.
In conclusion, the present data are consistent with the hypothesis that activation of central 5‐HT1A receptors potentiate whilst activation of 5‐HT1B/1D receptors attenuate the reflex activation of cardiac preganglionic vagal motoneurones evoked by stimulation of upper airway receptors with smoke in rabbits.

British Journal of Pharmacology (1998) 125, 409–417; doi:10.1038/sj.bjp.0702085
Pharmacological characterization of the nociceptin receptor mediating hyperalgesia in the mouse tail withdrawal assay
Authors: Calò G , Rizzi A , Marzola G , Guerrini R , Salvadori S , Beani L , Regoli D , Bianchi C 
Published: January 2005

The newly discovered neuropeptide nociceptin (NC) has recently been reported to be the endogenous ligand of the opioid‐like orphan receptor. Despite its structural similarity to opioids, when injected intracerebroventricularly (i.c.v.) in the mouse, NC exerts a direct hyperalgesic effect and reverses opioid‐induced analgesia. In the present investigation, these two effects of NC were evaluated under the same experimental conditions; in addition, a pharmacological characterization of the receptor mediating these central effects of NC was attempted.
NC caused a dose dependent (0.1–10 nmol/mouse), naloxone‐insensitive reduction of tail withdrawal latency with a maximal effect of about 50% of the reaction time observed in saline injected mice. In the same range of doses, NC inhibited morphine (1 nmol/mouse) induced analgesia.
The effects of the natural peptide were mimicked by NCNH2 and NC(1–13)NH2 (all tested at 1 nmol/mouse) while 1 nmol NC(1–9)NH2 was found to be inactive either in reducing tail withdrawal latency or in preventing morphine analgesia.
[Phe1ψ(CH2‐NH)Gly2]NC(1–13)NH2 ([F/G]NC(1–13)NH2), which has been shown to antagonize NC effects in the mouse vas deferens, acted as an agonist, mimicking NC effects in both the experimental paradigms. In addition, when NC and [F/G]NC(1–13)NH2 were given together, their effects were additive.
These results demonstrate that both the direct hyperalgesic action and the anti‐morphine effect of NC can be studied under the same experimental conditions in the mouse tail withdrawal assay. Moreover, the pharmacological characterization of the NC functional site responsible for these actions compared with the peripherally active site, indicates the existence of important differences between peripheral and central NC receptors.

British Journal of Pharmacology (1998) 125, 373–378; doi:10.1038/sj.bjp.0702087
Cyclic GMP‐dependent and cyclic GMP‐independent actions of nitric oxide on the renal afferent arteriole
Authors: Trottier Greg , Triggle Chris R , O'Neill Sean K , Loutzenhiser Rodger 
Published: January 2005

The effects of exogenous NO and endothelial‐derived NO (EDNO) on the afferent arteriole were investigated in the in vitro perfused hydronephrotic rat kidney. Vessels were pre‐constricted with angiotensin II (0.1–0.3 nM) or KCl (30 mM). NO was infused directly into the renal artery at concentrations ranging from 30–9000 nM. ODQ (10, 30 μM) was administered to examine the effects of guanylyl cyclase inhibition. Kidneys were treated with ibuprofen (10 μM) to avoid actions of prostaglandins.
During angiotensin II‐induced vasoconstriction, NO elicited vasodilation at concentrations of 30–900 nM (EC50=200 nM) and ODQ caused a 10 fold shift in NO‐sensitivity (EC50 1600 nM). During KCl‐induced vasoconstriction, NO elicited a maximal dilation of 82±9% at 9000 nM (EC50 2000 nM) and ODQ had no effect. Thus in the presence of ODQ, the NO concentration‐response curves for KCl‐ and angiotensin II‐induced vasoconstriction were identical (P>0.2).
To assess the possible role of cyclic GMP‐independent mechanisms in the actions of EDNO, we compared the effects of L‐NAME, ODQ and ODQ+L‐NAME on acetylcholine‐induced vasodilation. Angiotensin II reduced afferent arteriolar diameters from 16.7±0.5 to 8.1±0.8 microns and acetylcholine fully reversed this effect (16.9±0.5 microns). ODQ restored the angiotensin II response in the presence of acetylcholine (7.1±0.6 microns) and the subsequent addition of L‐NAME had no further effect (6.8±0.7 microns). Similarly, L‐NAME alone, fully reversed the actions of acetylcholine.
Our findings indicate that exogenous NO is capable of eliciting renal afferent arteriolar vasodilation through both cyclic GMP‐dependent and cyclic GMP‐independent mechanisms. The cyclic GMP‐independent action of NO did not require K+ channel activation, as it could be elicited in the presence of 30 mM KCl. Finally, although cyclic GMP‐independent effects of exogenous NO could be demonstrated in our model, EDNO appears to act exclusively through cyclic GMP.

British Journal of Pharmacology (1998) 125, 563–569; doi:10.1038/sj.bjp.0702090
NK‐3 receptors mediate enhancement of substance P release from capsaicin‐sensitive spinal cord afferent terminals
Authors: Schmid Giovanna , Carità Francesca , Bonanno Giambattista , Raiteri Maurizio 
Published: January 2005

The effects of NK‐3 receptor agonists on the release of substance P‐immunoreactivity (SP‐LI) have been investigated using superfused rat spinal cord synaptosomes.
The Ca2+‐dependent overflow of SP‐LI evoked by 35 mM KCl was concentration‐dependently enhanced by senktide (EC50=52 nM; maximal effect=70%) or [MePhe7]NKB (EC50=5.5 nM; maximal effect=125%), both selective agonists at receptors of the NK‐3 type.
The potentiation of the SP‐LI overflow elicited by 100 nM senktide or [MePhe7]NKB was prevented by the NK‐3 receptor antagonist (+)‐SR142801. The antagonist halved, at 10 nM, and almost abolished, at 100 nM, the effect of both agonists. The effect of senktide or [MePhe7]NKB was insensitive to antagonists at NK‐1 or NK‐2 receptors.
Capsaicin (0.1–1 μM) stimulated SP‐LI release in a concentration‐dependent manner from spinal cord synaptosomes. The SP‐LI overflow elicited by 1 μM capsaicin was completely dependent on external Ca2+. Senktide could not affect the capsaicin‐evoked release of SP‐LI.
Senktide failed to potentiate the K+‐evoked overflow of SP‐LI from synaptosomes previously exposed for 15 min in superfusion to capsaicin.
The results show that release‐enhancing NK‐3 receptors are located on axon terminals of capsaicin‐sensitive primary afferent neurones in the spinal cord. Antagonists at NK‐3 receptors might help controlling pain transmission.

British Journal of Pharmacology (1998) 125, 621–626; doi:10.1038/sj.bjp.0702093
Analysis of the 5‐HT1Areceptor involvement in passive avoidance in the rat
Authors: Misane Ilga , Johansson Christina , Ove Ögren Sven 
Published: January 2005

The effects of the 5‐HT2A/2Cagonist DOB, the selective 5‐HT1Aagonist NDO 008 (3‐dipropylamino‐5‐hydroxychroman), and the two enantiomers of the selective 5‐HT1Aagonist 8‐OH‐DPAT (R(+)‐8‐OH‐DPAT and S(−)‐8‐OH‐DPAT) were studied in a step‐through passive avoidance (PA) test in the male rat.The 5‐HT1Aagonists injected prior to training (conditioning) produced a dose‐dependent impairment of PA retention when examined 24 h later. R(+)‐8‐OH‐DPAT was four times more effective than S(−)‐8‐OH‐DPAT to cause an impairment of PA retention. Both NDO 008 and the two enantiomers of 8‐OH‐DPAT induced the serotonin syndrome at the dose range that produced inhibition of the PA response, thus, indicating activation of postsynaptic 5‐HT1Areceptors.Neither NDO 008 nor R(+)‐8‐OH‐DPAT induced head‐twitches, a behavioural response attributed to stimulation of postsynaptic 5‐HT2Areceptors. In contrast, DOB induced head‐twitches at the 0.01 mg kg−1dose while a 200 times higher dose was required to produce a significant impairment of PA retention.The impairment of PA retention induced by both NDO 008 and R(+)‐8‐OH‐DPAT was fully blocked by the active S(+)‐ enantiomer of the selective 5‐HT1Aantagonist WAY 100135 and the mixed 5‐HT1A/β‐adrenoceptor antagonist L(−)‐alprenolol. In contrast, the mixed 5‐HT2A/2Cantagonists ketanserin and pirenperone were found to be ineffective. Moreover, the β2‐adrenoceptor antagonist ICI 118551, the β1‐antagonist metoprolol as well as the mixed β‐adrenoceptor blocker D(+)‐alprenolol all failed to modify the deficit of PA retention by NDO 008 and R(+)‐8‐OH‐DPAT. None of the 5‐HT1Aor 5‐HT2A/2Creceptor antagonists tested or the β‐blockers altered PA retention by themselves.A 3 day pretreatment procedure (200+100+100 mg kg−1) with the tryptophan hydroxylase inhibitor p‐chlorophenylalanine (PCPA) did not alter PA retention and did not prevent the inhibitory action of the 5‐HT1Aagonists, indicating that their effects on PA do not depend on endogenous 5‐HT.The effects of NDO 008 on PA were also studied using a state‐dependent learning paradigm. NDO 008 was found to produce a disruption of PA when given either prior to training or retention or both prior to training and retention but it failed to affect PA retention when given immediately after training.These findings indicate that the deficit of passive avoidance retention induced by the 5‐HT1Aagonists is mainly a result of stimulation of postsynaptic 5‐HT1Areceptors but not 5‐HT2Areceptors. The 5‐HT1Areceptor stimulation appears to interfere with learning processes operating at both acquisition and retrieval.British Journal of Pharmacology(1998)125, 499–509; doi:10.1038/sj.bjp.0702098
Inhibitors of spasmogen‐induced Ca2+ channel suppression in smooth muscle cells from small intestine
Authors: Unno T , Beech D J , Komori S , Ohashi H 
Published: January 2005

Whole‐cell patch‐clamp recordings were made from smooth muscle cells isolated from the longitudinal muscle layer of guinea‐pig ileum. Carbachol (acting at muscarinic receptors) or histamine (acting at H1 histamine receptors) suppressed Ca2+ channel current. The effect of either agonist had an initial transient component followed by a sustained component.
Wortmannin inhibited transient and sustained components of carbachol‐induced Ca2+ channel current suppression: half‐effective inhibitory concentrations (IC50) were 1.1 μM and 0.6 μM for the two components respectively. Wortmannin also inhibited the transient phase of carbachol‐induced cationic current (IC50 1.6 μM) and Ca2+‐dependent K+‐current (IC50 1.7 μM). Wortmannin did not appear to produce any direct block of cationic channels or Ca2+ channels.
Intracellular application of the phospholipase inhibitor D609 (tricyclodecan‐9‐ylxanthogenate) inhibited transient and sustained components of histamine action on the Ca2+ channel current: the IC50 was about 130 μM for both components. Carbachol action on Ca2+ channels was also inhibited by D609. D609 had no significant direct blocking effect on Ca2+ channels, cationic channels activated by carbachol, or Ca2+‐activated K+‐current in response to flash‐photolysis of caged‐inositol 1,4,5‐trisphosphate.
Micromolar concentrations of wortmannin and D609 are inhibitors of both components of spasmogen‐induced Ca2+ channel suppression. The data suggest that both components are mediated by a common, or similar, signal transduction element which is a phospholipase C (PLC) or phospholipase D (PLD) isoform.

British Journal of Pharmacology (1998) 125, 667–674; doi:10.1038/sj.bjp.0702112
Effects of mexiletine on ATP sensitive K+ channel of rat skeletal muscle fibres: a state dependent mechanism of action
Authors: Tricarico Domenico , Barbieri Mariagrazia , Franchini Carlo , Tortorella Vincenzo , Conte Camerino Diana 
Published: January 2005

The effects of mexiletine were evaluated on the ATP‐sensitive K+ channel (KATP) of rat skeletal muscle fibres using patch clamp techniques. The effects of mexiletine were studied on macropatch currents 20 s (maximally activated), 8 min (early stage of rundown) and 15 min (late stage of rundown) after excision in the absence or in the presence of internal ADP (50–100 μM) or UDP (500 μM). In addition, the effects of mexiletine were tested on single channel.
In the absence of ADP and UDP, mexiletine inhibited the current through maximally activated channels with an IC50 of −5.58±0.3 M. Nucleoside diphosphates shifted the current versus mexiletine concentration relationship to the right on the log concentration axis. UDP (500 μM) was more efficacious than ADP (50–100 μM) in this effect.
At the early stage of rundown, the sensitivity of the channel to mexiletine was reduced and nucleoside diphosphates, particularly UDP, antagonized the effect of mexiletine. At the late stage of rundown, mexiletine did not affect the currents.
At the single channel level, 1 μM mexiletine reduced the mean burst duration by 63% and prolonged the arithmetic mean closed time intervals between the bursts of openings without altering the open time and closed time distributions. Mexiletine did not affect the single channel conductance.
These results show that in skeletal muscle, mexiletine is a state‐dependent KATP channel inhibitor which either acts through the nucleotide binding site or a site allosterically coupled to it.

British Journal of Pharmacology (1998) 125, 858–864; doi:10.1038/sj.bjp.0702117
iNOS contribution to the NMDA‐induced excitotoxic lesion in the rat striatum
Authors: Lecanu L , Verrecchia C , Margaill I , Boulu R G , Plotkine M 
Published: January 2005

The aim of this study was to assess whether an excitotoxic insult induced by NMDA may induce an iNOS activity which contributes to the lesion in the rat striatum.
For this purpose, rats were perfused with 10 mM NMDA through a microdialysis probe implanted in the left striatum. Microdialysate nitrite content, striatal Ca‐independent nitric oxide synthase activity and lesion volume were measured 48 h after NMDA exposure in rats treated with dexamethasone (DXM) (3 mg kg−1×4) or aminoguanidine (AG) (100 mg kg−1×4).
A significant increase in microdialysate nitrite content and in the Ca‐independent NOS activity was observed 48 h after NMDA infusion. Both these increases were reduced by DXM and AG. The NMDA‐induced striatal lesion was also reduced by both treatments.
Our results demonstrate that NMDA excitotoxic injury induces a delayed, sustained activation of a Ca‐independent NOS activity. This activity is blocked by DXM and AG, strongly suggesting the involvement of iNOS. The fact that AG and DXM reduce the NMDA‐elicited lesion suggests that iNOS contributes to the brain damage induced by excitotoxic insult.

British Journal of Pharmacology (1998) 125, 584–590; doi:10.1038/sj.bjp.0702119
Effects of propafenone and 5‐hydroxy‐propafenone on hKv1.5 channels
Authors: Franqueza Laura , Valenzuela Carmen , Delpón Eva , Longobardo Mónica , Caballero Ricardo , Tamargo Juan 
Published: January 2005

The goal of this study was to analyse the effects of propafenone and its major metabolite, 5‐hydroxy‐propafenone, on a human cardiac K+ channel (hKv1.5) stably expressed in Ltk− cells and using the whole‐cell configuration of the patch‐clamp technique.
Propafenone and 5‐hydroxy‐propafenone inhibited in a concentration‐dependent manner the hKv1.5 current with KD values of 4.4±0.3 μM and 9.2±1.6 μM, respectively.
Block induced by both drugs was voltage‐dependent consistent with a value of electrical distance (referenced to the cytoplasmic side) of 0.17±0.55 (n=10) and 0.16±0.81 (n=16).
The apparent association (k) and dissociation (l) rate constants for propafenone were (8.9±0.9)×106 M−1 s−1 and 39.5±4.2 s−1, respectively. For 5‐hydroxy‐propafenone these values averaged (2.3±0.3)×106 M−1 s−1 and 21.4±3.1 s−1, respectively.
Both drugs reduced the tail current amplitude recorded at −40 mV after 250 ms depolarizing pulses to +60 mV, and slowed the deactivation time course resulting in a ‘crossover’ phenomenon when the tail currents recorded under control conditions and in the presence of each drug were superimposed.
Both compounds induced a small but statistically significant use‐dependent block when trains of depolarizations at frequencies between 0.5 and 3 Hz were applied.
These results indicate that propafenone and its metabolite block hKv1.5 channels in a concentration‐, voltage‐, time‐ and use‐dependent manner and the concentrations needed to observe these effects are in the therapeutical range.

British Journal of Pharmacology (1998) 125, 969–978; doi:10.1038/sj.bjp.0702129