bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and pharmacological characterization of genes encoding urotensin‐II peptides and their cognate G‐protein‐coupled receptors from the mouse and monkey
Authors: Elshourbagy Nabil A. , Douglas Stephen A. , Shabon Usman , Harrison Stephen , Duddy Graham , Sechler Jan L. , Ao Zhaohui , Maleeff Beverly E. , Naselsky Diane , Disa Jyoti , Aiyar Nambi V. 
Published: January 2005

Urotensin‐II (U‐II) and its receptor (UT) represent novel therapeutic targets for management of a variety of cardiovascular diseases. To test such hypothesis, it will be necessary to develop experimental animal models for the manipulation of U‐II/UT receptor system. The goal of this study was to clone mouse and primate preproU‐II and UT for pharmacological profiling.
Monkey and mouse preproU‐II genes were identified to encode 123 and 125 amino acids. Monkey and mouse UT receptors were 389, and 386 amino acids, respectively. Genomic organization of mouse genes showed that the preproU‐II has four exons, while the UT receptor has one exon.
Although initially viewed by many exclusively as cardiovascular targets, the present study demonstrates expression of mouse and monkey U‐II/UT receptor mRNA in extra‐vascular tissue including lung, pancreas, skeletal muscle, kidney and liver.
Ligand binding studies showed that [125I]h U‐II bound to a single sites to the cloned receptors in a saturable/high affinity manner (Kd 654±154 and 214±65 pM and Bmax of 1011±125 and 497±68 fmol mg−1 for mouse and monkey UT receptors, respectively). Competition binding analysis demonstrated equipotent, high affinity binding of numerous mammalian, amphibian and piscine U‐II isopeptides to these receptors (Ki=0.8 – 3 nM). Fluorescein isothiocyanate (FITC) labelled U‐II, bound specifically to HEK‐293 cells expressing mouse or monkey UT receptor, confirming cell surface expression of recombinant UT receptor.
Exposure of these cells to human U‐II resulted in an increase in intracellular [Ca2+] concentrations (EC50 3.2±0.8 and 1.1±0.3 nM for mouse and monkey UT receptors, respectively) and inositol phosphate (Ip) formation (EC50 7.2±1.8 and 0.9±0.2 nM for mouse and monkey UT receptors, respectively) consistent with the primary signalling pathway for UT receptor involving phospholipase C activation.

British Journal of Pharmacology (2002) 136, 9–22; doi:10.1038/sj.bjp.0704671
Pharmacology of the nitric oxide receptor, soluble guanylyl cyclase, in cerebellar cells
Authors: Bellamy Tomas C. , Garthwaite John 
Published: January 2005

The nitric oxide (NO) receptor, soluble guanylyl cyclase (sGC), is commonly manipulated pharmacologically in two ways. Inhibition of activity is achieved using 1‐H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐l‐one (ODQ) which oxidizes the haem prosthetic group to which NO binds, while the compound 3‐(5‐hydroxymethyl‐2‐furyl)‐1‐benzylindazole (YC‐1) is considered an ‘allosteric’ activator. Knowledge of how these agents function and interact in a normal cellular environment is limited. These issues were addressed using rat cerebellar cells.
Inhibition by ODQ was not simply competitive with NO. The rate of onset was ODQ concentration‐dependent and developed in two kinetic phases. Recovery from inhibition occurred with a half‐time of ∼5 min.
YC‐1 slowed the rate at which sGC deactivated on removal of NO by 45 fold, consistent with YC‐1 increasing the potency of NO for sGC. YC‐1 also enhanced the maximal response to NO by 2 fold. Furthermore, when added to cells in which sGC was 90% desensitized, YC‐1 abruptly enhanced sGC activity to a degree that indicated partial reversal of desensitization.
After pre‐exposure to YC‐1, sGC became resistant to inhibition by ODQ. In addition, YC‐1 rapidly reversed inhibition by ODQ in cells and for purified sGC, suggesting that YC‐1 either increases the NO affinity of the oxidized sGC haem or reverses haem oxidation.
It is concluded that the actions of ODQ and YC‐1 on sGC are broadly similar in cells and purified preparations. Additionally, YC‐1 transiently reverses sGC desensitization in cells. It is hypothesized that YC‐1 has multiple actions on sGC, and thereby both modifies the NO binding site and enhances agonist efficacy.

British Journal of Pharmacology (2002) 136, 95–103; doi:10.1038/sj.bjp.0704687
Discrimination by SZL49 between contractions evoked by noradrenaline in longitudinal and circular muscle of human vas deferens
Authors: Amobi Nnaemeka I. B. , Guillebaud John , Kaisary A V. , Turner Eileen , Smith I Christopher H. 
Published: January 2005

The effects of irreversible α1‐adrenoceptor antagonists, SZL‐49 (an alkylating analogue of prazosin), dibenamine and benextramine on contractions to noradrenaline (NA) in longitudinal and circular muscle of human epididymal vas deferens were investigated. Competitive α1‐adrenoceptor antagonists were also used to further characterize the α1‐adrenoceptor subtype stimulated by NA in longitudinal and circular muscle.
NA evoked concentration‐dependent contractions of both muscle types (pD2; 5.4 and 5.2 respectively). The contraction of circular muscle was comparatively more sensitive than that of longitudinal muscle to pretreatment with SZL‐49. In contrast, dibenamine or benextramine produced comparable effects in both muscle types.
The relationship between receptor occupancy and contraction in either longitudinal or circular muscle was nonlinear, with half‐maximal response requiring similar receptor occupancy (longitudinal muscle 14%, circular muscle 16%). Maximal response in both muscle types occurred with little or no receptor reserve (<10%).
The competitive α1‐adrenoceptor antagonists produced dextral shifts of the dose‐response curves to NA in longitudinal and circular muscle. The inhibitory potencies, estimated from the apparent pKB values were significantly different in longitudinal and circular muscle respectively for either WB 4101 (pKB, 8.6 and 9.5) or RS‐17053 (pKB, 7.1 and 9.0) but not for Rec 15/2739 (pKB, 9.2 and 9.8) or HV 723 (pKB, 8.3 and 8.4).
In conclusion, the potency profile of the competitive α1‐adrenoceptor antagonists and the lack of different receptor reserves for NA in the muscle types suggest that the discriminatory effects of SZL‐49 is primarily due to a predominance of the α1L‐adrenoceptor subtype in longitudinal muscle and α1A‐subtype in circular muscle.

British Journal of Pharmacology (2002) 136, 127–135; doi:10.1038/sj.bjp.0704689
Interaction of group I mGlu and NMDA receptor agonists within the dorsal horn of the spinal cord of the juvenile rat
Authors: Dang K , Naeem S , Walker K , Bowery N G , Urban L 
Published: January 2005

The modulatory effects of mGlu receptors on NMDA‐induced potential changes in spinal motoneurones were studied in vitro.
Selective activation of mGlu5 receptors by 10 μM (RS)‐2‐Chloro‐5‐hydroxyphenylglycine (CHPG; EC50=280±24 μM) did not produce any change in the ventral root potential. However, the same concentration of CHPG (10 min perfusion) significantly attenuated the NMDA‐induced ventral root depolarization (VRD). The effect persisted for 10 min after washout. NMDA‐induced responses returned to control in 30 min. Brief co‐application of CHPG and NMDA did not alter the NMDA‐induced response indicating lack of direct receptor interaction.
The attenuating effect of CHPG on the NMDA‐induced VRD was inhibited by the mGluR5 receptor antagonist, 2‐methyl‐6‐phenyl‐ethynylpyridine (MPEP).
In the presence of CGP56433A, a GABAB receptor antagonist, the NMDA‐induced VRD was unchanged. However, NMDA‐induced responses were potentiated after 10 min co‐application of CHPG and CGP56433A.
(2R,4R)‐4‐aminopyrrolidine‐2,4‐dicarboxylate ((2R,4R)‐APDC), a group II mGlu receptor agonist did not attenuate the NMDA‐induced response.
Under normal physiological conditions group I mGlu receptor agonists activate at least two populations of neurones: (1) GABA‐ergic cells, which could release GABA and inhibit dorsal horn neurones, and (2) deep dorsal horn neurones/motoneurones which express NMDA receptors. Therefore, activation of mGlu5 receptors located on GABA‐ergic interneurones could influence any direct potentiating interaction between mGlu5 and NMDA receptors in spinal cord and result in depression of the VRD. In the presence of a GABAB receptor antagonist, the direct synergistic interaction is unmasked. These data suggest that group I mGlu receptors provide a complex modulation of spinal synaptic processes.

British Journal of Pharmacology (2002) 136, 248–254; doi:10.1038/sj.bjp.0704698
Regulation by PGE2 of the production of interleukin‐6, macrophage colony stimulating factor, and vascular endothelial growth factor in human synovial fibroblasts
Authors: Inoue Hideo , Takamori Makiko , Shimoyama Yoshihito , Ishibashi Hideaki , Yamamoto Seizo , Koshihara Yasuko 
Published: January 2005

We examined the effects of endogenous prostaglandin E2 (PGE2) on the production of interleukin‐6 (IL‐6), macrophage colony stimulating factor (M‐CSF), and vascular endothelial growth factor (VEGF) by interleukin‐1β (IL‐1β)‐stimulated human synovial fibroblasts.
NS‐398 (1 μM), a cyclo‐oxygenase‐2 (COX‐2) inhibitor, inhibited IL‐6 and VEGF production (35±4% and 26±2%, respectively) but enhanced M‐CSF production (38±4%) by IL‐1β (1 ng ml−1) in synovial fibroblasts isolated from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). Exogenous PGE2 completely abolished the effects of NS‐398 on the production of each mediator by OA fibroblasts stimulated with IL‐1β.
8‐Bromo cyclic AMP and dibutyryl cyclic AMP, cyclic AMP analogues, mimicked the effects of PGE2 on IL‐6, M‐CSF, and VEGF production by OA fibroblasts.
The EP2 selective receptor agonist ONO‐AE1‐259 (2 nM) and the EP4 selective receptor agonist ONO‐AE1‐329 (2 or 20 nM), but not the EP1 selective receptor agonist ONO‐DI‐004 (1 μM) and the EP3 selective receptor agonist ONO‐AE‐248 (1 μM), replaced the effects of PGE2 on IL‐6, M‐CSF, and VEGF production by OA and RA fibroblasts stimulated with IL‐1β in the presence of NS‐398.
Both OA and RA fibroblasts expressed mRNA encoding EP2 and EP4 but not EP1 receptors. In addition, up‐regulation of EP2 and EP4 receptor mRNAs was observed at 3 h after IL‐1β treatment.
These results suggest that endogenous PGE2 regulates the production of IL‐6, M‐CSF, and VEGF by IL‐1β‐stimulated human synovial fibroblasts through the activation of EP2 and EP4 receptors with increase in cyclic AMP.

British Journal of Pharmacology (2002) 136, 287–295; doi:10.1038/sj.bjp.0704705
[Nphe1,Arg14,Lys15]Nociceptin‐NH2, a novel potent and selective antagonist of the nociceptin/orphanin FQ receptor
Authors: Calo Girolamo , Rizzi Anna , Rizzi Daniela , Bigoni Raffaella , Guerrini Remo , Marzola Giuliano , Marti Matteo , McDonald John , Morari Michele , Lambert David G , Salvadori Severo , Regoli Domenico 
Published: January 2005

Nociceptin/orphanin FQ (N/OFQ) modulates several biological functions by activating a specific G‐protein coupled receptor (NOP). Few molecules are available that selectively activate or block the NOP receptor. Here we describe the in vitro and in vivo pharmacological profile of a novel NOP receptor ligand, [Nphe1,Arg14,Lys15]N/OFQ‐NH2 (UFP‐101).
UFP‐101 binds to the human recombinant NOP receptor expressed in Chinese hamster ovary (CHO) cells with high affinity (pKi 10.2) and shows more than 3000 fold selectivity over classical opioid receptors. UFP‐101 competitively antagonizes the effects of N/OFQ on GTPγ35S binding in CHOhNOP cell membranes (pA2 9.1) and on cyclic AMP accumulation in CHOhNOP cells (pA2 7.1), being per se inactive at concentrations up to 10 μM.
In isolated peripheral tissues of mice, rats and guinea‐pigs, and in rat cerebral cortex synaptosomes preloaded with [3H]‐5‐HT, UFP‐101 competitively antagonized the effects of N/OFQ with pA2 values in the range of 7.3–7.7. In the same preparations, the peptide was inactive alone and did not modify the effects of classical opioid receptor agonists.
UFP‐101 is also active in vivo where it prevented the depressant action on locomotor activity and the pronociceptive effect induced by 1 nmol N/OFQ i.c.v. in the mouse. In the tail withdrawal assay, UFP‐101 at 10 nmol produces per se a robust and long lasting antinociceptive effect.
UFP‐101 is a novel, potent and selective NOP receptor antagonist which appears to be a useful tool for future investigations of the N/OFQ‐NOP receptor system.

British Journal of Pharmacology (2002) 136, 303–311; doi:10.1038/sj.bjp.0704706
Modification of NMDA responses by tri‐n‐butyltin in rat brain neurons
Authors: Kanemoto Yumiko , Ishibashi Hitoshi , Matsuo Shinichiro , Oyama Yasuo , Akaike Norio 
Published: January 2005

The effects of the organotin, tri‐n‐butyltin (TBT), on N‐methyl‐D‐aspartate (NMDA) induced membrane currents were investigated in order to evaluate possible neuronal actions of this toxic environmental pollutant. Experiments were conducted on neurons acutely dissociated from the rat dorsal motor nucleus of vagus (DMV) using the nystatin‐perforated patch clamp recording technique.
In Mg2+‐free physiological recording solutions, the application of NMDA to single DMV neurons held at a holding potential (VH) of −40 mV evoked an inward current which rapidly reached a peak before declining to a steady‐state inward current. This was followed, immediately after NMDA washout, by a transient outward current. TBT (100 nM) reversibly caused a slight reduction in the inward currents and greatly increased the amplitude of the outward currents.
The reversal potential of the NMDA‐induced outward current in the presence of TBT was −86.7 mV, close to the theoretical K+ equilibrium potential of −85.7 mV.
The NMDA‐induced outward current was completely blocked when the K+ in the internal solution was replaced with equimolar Cs+. Under these conditions, the NMDA induced current was more sustained and was unaffected by TBT.
The NMDA‐induced outward current was markedly inhibited by 5 mM tetraethylammonium chloride and 300 nM charybdotoxin, and it was abolished by removal of extracellular Ca2+, suggesting that the outward current was due to the activation of Ca2+‐activated K+ channels by Ca2+ influx through NMDA receptors.
In conclusion, in rat DMV neurons, TBT potentiates the Ca2+‐activated K+ current induced by NMDA application without having any direct effects on the NMDA‐induced inward current. Given the significant role of NMDA receptor mediated excitation in various physiological and pathological processes, the modulation of this response by TBT may have an important influence on neuronal function.

British Journal of Pharmacology (2002) 136, 201–206; doi:10.1038/sj.bjp.0704707
Involvement of 5‐HT1B and 5‐HT1D receptors in sumatriptan mediated vasocontractile response in rabbit common carotid artery
Authors: Akin Demet , Gurdal Hakan 
Published: January 2005

In this study we examined the involvement of 5‐HT1B and 5‐HT1D receptors in the vasocontractile response induced by 5‐HT1B/D‐receptor agonist sumatriptan in rabbit common carotid artery (CCA).
Immunoblotting experiments using specific antisera against 5‐HT1B or 5‐HT1D receptors revealed the presence of one weak (at 93 kD for 5‐HT1B or at 105 kD for 5‐HT1D) and one strong band (at 46 kD for 5‐HT1B or at 52 kD for 5‐HT1D) in CCA.
Sumatriptan‐mediated vasocontractile response was antagonized by SB216641 with an apparent pKb value of 8.6, which was consistent with its affinity for 5‐HT1B receptor. Antagonism by BRL15572 was weak and calculated apparent pKb (6.0) value was consistent with its affinity for 5‐HT1B subtype (but not for 5‐HT1D subtype). This result indicates insignificant or no involvement of 5‐HT1D receptor in the vasocontractile response.
The vasocontractile response induced by sumatriptan was highly sensitive to pertussis toxin treatment of CCA. Nicardipine, a calcium channel blocker, also potently antagonized vasocontractile response induced by sumatriptan.
5‐HT, but not sumatriptan, stimulated inositol phosphate accumulation in CCA.
These results indicate that stimulation of 5‐HT1B subtype activate a pertussis toxin (PTX) sensitive G protein (Go/Gi) and mediate vasocontraction, in which L‐type voltage dependent calcium channels are involved.

British Journal of Pharmacology (2002) 136, 177–182; doi:10.1038/sj.bjp.0704709
Agonist‐directed trafficking explaining the difference between response pattern of naratriptan and sumatriptan in rabbit common carotid artery
Authors: Akin Demet , Onaran H Ongun , Gurdal Hakan 
Published: January 2005

Sumatriptan or eletriptan produced vasocontraction in common carotid artery (CCA) by stimulating 5HT1B receptors (see also Akin & Gurdal, this issue).
Naratriptan as a 5HT1B/D agonist, was unable to produce vasocontraction in this artery, but inhibited the vasocontractile response induced by sumatriptan or eletriptan.
All these agonists inhibited forskolin‐stimulated cyclic AMP production with comparable potencies and maximal responses. This inhibition was mediated by 5HT1B receptors: 5HT1B antagonist SB216641 (1 μM) completeley antagonized sumatriptan‐, eletriptan‐ or naratriptan‐induced cyclic AMP inhibition, but 5HT1D antagonist BRL15572 (1 μM) did not affect this response.
Naratriptan‐induced stimulation of 5‐HT1B receptors resulted only in adenylate cyclase inhibition, whereas stimulation of these receptors by sumatriptan or eletriptan produced vasocontraction as well. Hence, we concluded that the 5HT1B‐mediated inhibition of adenylate cyclase was not a sufficient condition to couple the receptor stimulation to vasocontraction.
We discussed agonist‐induced trafficking as a plausible mechanism for the observed phenomenon.

British Journal of Pharmacology (2002) 136, 171–176; doi:10.1038/sj.bjp.0704710
Arginine to lysine 108 substitution in recombinant CYP1A2 abolishes methoxyresorufin metabolism in lymphoblastoid cells
Authors: Hadjokas Nicholas E , Dai Renke , Friedman Fred K , Spence Michael J , Cusack Barry J , Vestal Robert E , Ma Yongsheng 
Published: January 2005

Cytochrome P4501A2 (CYP1A2) activates a large number of procarcinogens to carcinogens. Phytochemicals such as flavones can inhibit CYP1A2 activity competitively, and hydroxylated derivatives of flavone (galangin) may be potent, selective inhibitors of CYP1A2 activity relative to CYP1A1 activity. Molecular modelling of the CYP1A2 interaction with hydroxylated derivatives of flavone suggests that a number of hydrophobic residues of the substrate‐binding domain engage in hydrogen bonding with such inhibitors.
We have tested this model using site‐directed mutagenesis of these residues in expression plasmids transfected into the human B‐lymphoblastoid cell line, AHH‐1 TK+/−.
Consistent with the molecular model's predicted placement in the active site, amino acid substitutions at the predicted residues abolished CYP1A2 enzymatic activity.
Transfected cell lines contained equal amounts of immunoreactive CYP1A2.
Our results support the molecular model's prediction of the critical amino acid residues present in the hydrophobic active site, residues that can hydrogen bond with CYP1A2 inhibitors and modify substrate binding and/or turnover.

British Journal of Pharmacology (2002) 136, 347–352; doi:10.1038/sj.bjp.0704711
Effects of adenosine A1 and A2A receptor activation on the evoked release of glutamate from rat cerebrocortical synaptosomes
Authors: Marchi Mario , Raiteri Luca , Risso Francesca , Vallarino Annalisa , Bonfanti Andrea , Monopoli Angela , Ongini Ennio , Raiteri Maurizio 
Published: January 2005

The effects of adenosine A2A and A1 receptor activation on the release of glutamate were studied in rat cerebral cortex synaptosomes exposed in superfusion to adenosine receptor ligands.
Adenosine (0.1 μM) produced a significant potentiation of the Ca2+‐dependent K+(15 mM)‐evoked [3H]‐D‐aspartate overflow (20.4±3.5%), which was blocked by A2A blocker SCH58261 (0.1 μM). At higher concentrations (10 – 1000 μM) adenosine inhibited in a DPCPX‐sensitive manner the Ca2+‐dependent K+‐evoked [3H]‐D‐aspartate overflow. The inhibitory effect of adenosine at 1000 μM was significantly increased by SCH58261. This inhibition was antagonized by 1 μM DPCPX. Adenosine did not produce any effect on basal release.
The A2A receptor agonist CGS 21680 was ineffective on basal release, but stimulated the Ca2+‐dependent K+‐evoked overflow of [3H]‐D‐aspartate (EC50 ≃ 1 pM). The effect of 0.01 nM CGS 21680 was totally sensitive to the A2A receptor antagonist SCH58261 (IC50 ≃5 nM).
The A1 receptor agonist CCPA inhibited the Ca2+‐dependent K+‐evoked [3H]‐D‐aspartate overflow (EC50 ≃ 20 nM). The effect of 100 nM CCPA was abolished by 100 nM of the A1 receptor antagonist DPCPX.
The K+(15 mM)‐evoked overflow of endogenous glutamate was enhanced by CGS 21680 (0.01 nM) and inhibited by CCPA (0.1 μM). The effect of CGS 21680 was abolished by SCH58261 (0.1 μM) and that of CCPA by DPCPX (0.1 μM).
It is concluded that adenosine and adenosine receptor agonists modulate glutamate release by activating inhibitory A1 and excitatory A2A receptors present on glutamatergic terminals of the rat cerebral cortex.

British Journal of Pharmacology (2002) 136, 434–440; doi:10.1038/sj.bjp.0704712
Enzymatic activation of endothelial protease‐activated receptors is dependent on artery diameter in human and porcine isolated coronary arteries
Authors: Hamilton Justin R , Moffatt James D , Tatoulis James , Cocks Thomas M 
Published: January 2005

Protease‐activated receptor (PAR)‐mediated vascular relaxations have been compared in coronary arteries of different diameters isolated from both humans and pigs.
Thrombin, trypsin, and the PAR1‐activating peptide, TFLLR, all caused concentration‐dependent relaxation of both large (epicardial; ∼2 mm internal diameter) and small (intramyocardial; ∼200 μm internal diameter) human coronary arteries. EC50 values for thrombin (0.006 u ml−1 in epicardial, 1.69 u ml−1 in intramyocardial) and trypsin (0.02 u ml−1 in epicardial, 1.05 u ml−1 in intramyocardial) were significantly (P<0.01) greater in intramyocardial arteries. By contrast, EC50 values for TFLLR were not different between epicardial (0.35 μM) and intramyocardial (0.43 μM) arteries.
In porcine coronary arteries, EC50 values for relaxations to thrombin (0.03 u ml−1 in epicardial 0.17 u ml−1 in intramyocardial) were also significantly (P<0.01) greater in the smaller arteries. EC50 values for both TFLLR and the PAR2‐activating peptide, SLIGKV, were not different between the two different‐sized pig coronary arteries.
PAR1‐immunoreactivity was localized to the endothelium of human epicardial and intramyocardial arteries and both PAR1‐ and PAR2‐immunoreactivity was observed in endothelial cells of equivalent porcine arteries.
These findings indicate that enzymatic activation of endothelial cell PARs in human (PAR1) and porcine (PAR1 and PAR2) coronary arteries is markedly reduced in intramyocardial arteries when compared with epicardial arteries, suggesting increased regulation of PAR‐mediated vascular responses in resistance‐type arteries.

British Journal of Pharmacology (2002) 136, 492–501; doi:10.1038/sj.bjp.0704714