bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and pharmacological evidence for modulation of kinin B1 receptor expression by endogenous glucocorticoids hormones in rats
Authors: Cabrini Daniela A , Campos Maria M , Tratsk Karla S , Merino Vanessa F , Silva José A , Souza Glória E P , Avellar Maria C W , Pesquero João B , Calixto João B 
Published: January 2005

The effect of endogenous glucocorticoid hormones on the expression of rat B1 receptors was examined by means of molecular and pharmacological functional approaches.
Rats were adrenalectomized (ADX), and 7 days after this procedure the intradermal injection of B1 receptor agonist des‐Arg9‐BK produced a significant increase in the paw volume, while only a weak effect was observed in sham‐operated animals. A similar increase in the contractile responses mediated by B1 agonist des‐Arg9‐BK was also observed in the rat portal vein in vitro.
Chemical ADX performed with mitotane (a drug that reduces corticosteroid synthesis) produced essentially the same up‐regulation of B1 receptors as that observed in ADX rats.
The modulation of B1 receptor expression was evaluated by ribonuclease protection assay, employing mRNA obtained from the lungs and paw of ADX rats.
Additionally, both paw oedema and contraction of portal vein mediated by B1 agonist des‐Arg9‐BK in ADX rats, were markedly inhibited by treatment with dexamethasone, or COX‐2 inhibitor meloxican, or with the NF‐κB inhibitor PDTC. Interestingly, the same degree of inhibition was achieved when the animals were treated with a combination of submaximal doses of dexamethasone and PDTC.
The involvement of NF‐κB pathway was further confirmed by mobility shift assay using nuclear extracts from lung, paw and heart of ADX rats. It was also confirmed that the treatment of ADX rats with dexamethasone, PDTC or dexamethasone plus PDTC completely inhibit NF‐κB activation caused by absence of endogenous glucucorticoid.
Together, the results of the present study provide, for the first time, molecular and pharmacological evidence showing that B1 kinin receptor expression can be regulated through endogenous glucocorticoids by a mechanism dependent on NF‐κB pathway. Clinical significance of the present findings stem from evidence showing the importance of B1 kinin receptors in the mediation of inflammatory and pain related responses.

British Journal of Pharmacology (2001) 132, 567–577; doi:10.1038/sj.bjp.0703846
Mediator involvement in antigen‐induced bronchospasm and microvascular leakage in the airways of ovalbumin sensitized Brown Norway rats
Authors: Hele Dave J , Birrell Mark A , Webber Stephen E , Foster Martyn L , Belvisi Maria G 
Published: January 2005

To determine which mediators are involved in antigen‐induced bronchospasm and microvascular leakage in the airways of ovalbumin sensitised Brown Norway rats we investigated the effect of a histamine H1 receptor antagonist, mepyramine, a 5‐HT receptor antagonist, methysergide, and a cys‐leukotriene‐1 receptor antagonist, montelukast.
Ovalbumin at 1 mg kg−1 i.v. caused a significant increase in microvascular leakage in the airways and at 3 mg kg−1 i.v. caused a significant increase in airways resistance.
Histamine (1 mg kg−1 i.v.), 5‐HT (0.1 mg kg−1 i.v.) and leukotriene D4 (LTD4, 50 μg kg−1 i.v.) caused a significant increase in microvascular leakage in the airways.
Mepyramine (1 mg kg−1 i.v.), methysergide (0.1 mg kg−1 i.v.), or montelukast (30 mg kg−1 i.v.) inhibited histamine, 5‐HT or LTD4 ‐induced microvascular leakage respectively.
Methysergide (0.1 mg kg−1 i.v.) reduced ovalbumin‐induced microvascular leakage in the trachea and at 0.3 mg kg−1 i.v. inhibited bronchospasm (38 and 58%, respectively). Montelukast (30 mg kg−1 p.o.) reduced ovalbumin‐induced microvascular leakage in airway tissue to basal levels (78%) and inhibited ovalbumin‐induced bronchospasm (50%). Mepyramine (3 mg kg−1 i.v.) had no effect on ovalbumin‐induced leakage or bronchospasm.
A combination of all three compounds (mepyramine, methysergide and montelukast) reduced ovalbumin‐induced microvascular leakage in airway tissue to basal levels (70 – 78%) and almost completely inhibited bronchospasm (92%).
Antigen‐induced bronchospasm appears to equally involve the activation of 5‐HT and cys‐leukotriene‐1 receptors whereas ovalbumin‐induced microvascular leakage appears to be predominantly mediated by cys‐leukotriene‐1 receptors.

British Journal of Pharmacology (2001) 132, 481–488; doi:10.1038/sj.bjp.0703847
Regulation of 5‐HT1A receptor‐stimulated [35S]‐GTPγS binding as measured by quantitative autoradiography following chronic agonist administration
Authors: Hensler Julie G , Durgam Hymavathi 
Published: January 2005

Because changes 5‐HT1A receptor number do not occur following repeated agonist treatment, we hypothesized that the basis for 5‐HT1A receptor desensitization involves changes in receptor‐G protein coupling. We measured the effect of repeated agonist administration on 5‐HT1A receptor‐stimulated [35S]‐GTPγS binding in forebrain areas, (i.e. anterior cingulate cortex, lateral septum, hippocampus, entorhinal cortex), and serotonergic cell body areas, the dorsal and median raphe nuclei.
Following treatment of rats with (±)8‐OH‐DPAT (1 mg kg−1, s.c.) for 7 or 14 days, 5‐HT1A receptor‐stimulated [35S]‐GTPγS binding was significantly attenuated in both the dorsal and median raphe nuclei.
5‐HT1A receptor‐stimulated [35S]‐GTPγS binding was significantly attenuated in the CA1 region of the hippocampus after 7, but not 14 days of 8‐OH‐DPAT administration. 5‐HT1A receptor‐stimulated [35S]‐GTPγS binding was not altered in other forebrain areas examined.
The binding of [3H]‐MPPF to 5‐HT1A receptor sites was not altered in any brain region examined following repeated agonist administration, suggesting that the observed changes in (±)8‐OH‐DPAT‐stimulated [35S]‐GTPγS binding were not due to changes in 5‐HT1A receptor number.
Our data indicate that in serotonergic cell body areas the regulation of presynaptic 5‐HT1A receptor function following repeated agonist administration occurs at the level of receptor‐G protein interaction. In forebrain areas, however, the regulation of postsynaptic 5‐HT1A receptor sensitivity appears not to be at the level of receptor‐G protein coupling.

British Journal of Pharmacology (2001) 132, 605–611; doi:10.1038/sj.bjp.0703855
α4 integrin‐dependent eosinophil recruitment in allergic but not non‐allergic inflammation
Authors: Teixeira Mauro M , Robinson Martyn K , Shock Anthony , Hellewell Paul G 
Published: January 2005

Although anti‐α4 integrin mAbs reduce eosinophil accumulation in several models of allergic inflammation, it is not clear whether this occurs via a direct action to block eosinophil α4 integrins or indirectly on another cell type. The role of α4 integrins on the accumulation of 111In‐labelled eosinophils in allergic and non‐allergic inflammation in guinea‐pig skin was therefore investigated.
Intradermal injection of antigen in sensitized skin sites induced accumulation of 111In‐eosinophils that was reduced up to 70% by two anti‐α4 integrin mAbs. In contrast, accumulation of 111In‐eosinophils to intradermal chemoattractants was unaffected by the same mAbs.
Accumulation of 111In‐eosinophils in allergic and non‐allergic conditions was partly inhibited by a low dose of an anti‐β2 integrin mAb. In combination with anti‐α4 integrin mAb, responses were not further reduced suggesting that these adhesion pathways are not additive or synergic.
Pretreating skin sites with antiserum or contaminating LPS did not reveal an α4 integrin dependent pathway for chemoattractant‐induced 111In‐eosinophil accumulation. These data suggest that α4 integrins are involved in the response to antigen in sensitized skin sites.
Pretreating 111In‐eosinophil with α4 integrin mAb blocked their adhesion to fibronectin in vitro but did not inhibit their accumulation in allergic inflammation suggesting that the blocking effect in vivo was eosinophil independent.
These data support the concept that targeting α4 integrins on cells other than eosinophils could control eosinophil accumulation and have therapeutic potential in allergic diseases such as asthma and atopic dermatitis.

British Journal of Pharmacology (2001) 132, 596–604; doi:10.1038/sj.bjp.0703857
Assessment of CFTR chloride channel openers in intact normal and cystic fibrosis murine epithelia
Authors: Cuthbert Alan W 
Published: January 2005

A method is described for the detection of CFTR chloride channel openers (ClCOs) and blockers. Murine colonic epithelia were used throughout, but the method is applicable to other epithelia and biopsy material.
The principle was to render the epithelial basolateral membranes electrically transparent so that the apical membrane alone could be voltage clamped. This was achieved by potassium depolarization on the basolateral side. Imposition of an apical to basolateral chloride gradient allowed the effects of ClCOs on an outward chloride current and on apical membrane conductance to be measured.
1‐ethyl‐2‐benzimidazolone (EBIO), forskolin, chlorzoxazone, and genistein all showed ClCO activity. In cystic fibrosis (CF) epithelia, either from CF null or CFΔF508 mice, EBIO showed only a minor effect, indicating that CFTR was the target in wild type tissues.
5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid (NPPB) was shown to block CFTR chloride channels. The blockade was pH and voltage‐dependent and indicated that while the charged form was the active moiety, movement into the cell depended on the unionized drug. It is concluded NPPB blocks CFTR from the cytosolic side and that the agent preferentially blocks at potentials opposing the inflow of chloride ions. No significant blockade was seen with either N‐phenylanthranilic acid (DPC) or with glibenclamide, under standard conditions.
The method described can be used to examine compounds reported to increase the trafficking of ΔF508 CFTR to the membrane or those capable of opening ΔF508 CFTR chloride channels and to differentiate between them. Further, the method distinguishes between chloride channel openers and those acting indirectly to increase the flux through CFTR chloride channels by indirect means, for example, hyperpolarization.

British Journal of Pharmacology (2001) 132, 659–668; doi:10.1038/sj.bjp.0703859
Transcriptional and translational regulation of calpain in the rat heart after myocardial infarction – effects of AT1 and AT2 receptor antagonists and ACE inhibitor
Authors: Sandmann Steffen , Yu Minghuan , Unger Thomas 
Published: January 2005

Recent studies demonstrated that the cardiac calpain system is activated during ischaemic events and is involved in cardiomyocyte injury. The aim of this study was to investigate the contribution of AT1 and AT2 receptors in the regulation of calpain‐mediated myocardial damage following myocardial infarction (MI).
Infarcted animals were treated either with placebo, the ACE inhibitor ramipril (1 mg kg−1 d−1), the AT1 receptor antagonist valsartan (10 mg kg−1 d−1) or the AT2 receptor antagonist PD 123319 (30 mg kg−1 d−1). Treatment was started 7 days prior to surgery. On day 1, 3, 7 and 14 after MI, gene expression and protein levels of calpain I, II and calpastatin were determined in left ventricular free wall (LVFW) and interventricular septum (IS). At day 3 and 14 post MI, morphological investigations were performed.
Calpain I mRNA expression and protein levels were increased in IS 14 days post MI, whereas mRNA expression and protein levels of calpain II were maximally increased in LVFW 3 days post MI. Ramipril and valsartan decreased mRNA and protein up‐regulation of calpain I and II, and reduced infarct size and interstitial fibrosis. PD 123319 did not affect calpain I or II up‐regulation in the infarcted myocardium, but decreased interstitial fibrosis. Calpastatin expression and translation were not affected by AT receptor antagonists or ACE inhibitor.
Our data demonstrate a distinct, temporary‐spatial up‐regulation of calpain I and II following MI confer with the hypothesis of calpain I being involved in cardiac remodelling in the late and calpain II contributing to cardiac tissue damage in the early phase of MI. The up‐regulation of calpain I and II is partly mediated via the AT1 receptor and can be reduced by ACE inhibitors and AT1 receptor antagonists.

British Journal of Pharmacology (2001) 132, 767–777; doi:10.1038/sj.bjp.0703860
Characterization of KCNQ5/Q3 potassium channels expressed in mammalian cells
Authors: Wickenden Alan D , Zou Anruo , Wagoner P Kay , Jegla Tim 
Published: January 2005

Heteromeric KCNQ5/Q3 channels were stably expressed in Chinese Hamster ovary cells and characterized using the whole cell voltage‐clamp technique. KCNQ5/Q3 channels were activated by the novel anticonvulsant, retigabine (EC50 1.4 μM) by a mechanism that involved drug‐induced, leftward shifts in the voltage‐dependence of channel activation (−31.8 mV by 30 μM retigabine). KCNQ5/Q3 channels were inhibited by linopirdine (IC50 7.7 μM) and barium (IC50 0.46 mM), at concentrations similar to those required to inhibit native M‐currents. These findings identify KCNQ5/Q3 channels as a molecular target for retigabine and raise the possibility that activation of KCNQ5/Q3 channels may be responsible for some of the anti‐convulsant activity of this agent. Furthermore, the sensitivity of KCNQ5/Q3 channels to linopirdine supports the possibility that potassium channels comprised of KCNQ5 and KCNQ3 may make a contribution to native M‐currents.British Journal of Pharmacology (2001) 132, 381–384; doi:10.1038/sj.bjp.0703861
The sulphonylurea glibenclamide inhibits multidrug resistance protein (MRP1) activity in human lung cancer cells
Authors: Payen Léa , Delugin Laurence , Courtois Arnaud , Trinquart Yolande , Guillouzo André , Fardel Olivier 
Published: January 2005

Glibenclamide, a sulphonylurea widely used for the treatment of non‐insulin‐dependent diabetes mellitus, has been shown to inhibit the activities of various ATP‐binding cassette (ABC) transporters. In the present study, its effects towards multidrug resistance protein 1 (MRP1), an ABC efflux pump conferring multidrug resistance and handling organic anions, were investigated.
Intracellular accumulation of calcein, an anionic dye substrate for MRP1, was strongly increased by glibenclamide in a dose‐dependent manner in MRP1‐overexpressing lung tumour GLC4/Sb30 cells through inhibition of MRP1‐related calcein efflux. By contrast, glibenclamide did not alter calcein levels in parental control GLC4 cells. Another sulphonylurea, tolbutamide, was however without effect on calcein accumulation in both GLC4/Sb30 and GLC4 cells.
Glibenclamide used at 12.5 μM was, moreover, found to strongly enhance the sensitivity of GLC4/Sb30 cells towards vincristine, an anticancer drug handled by MRP1.
Efflux of carboxy‐2′,7′‐dichlorofluorescein, an anionic dye handled by the ABC transporter MRP2 sharing numerous substrates with MRP1 and expressed at high levels in liver, was also strongly inhibited by glibenclamide in isolated rat hepatocytes.
In summary, glibenclamide reversed MRP1‐mediated drug resistance likely through inhibiting MRP1 activity and blocked organic anion efflux from MRP2‐expressing hepatocytes. Such effects associated with the known inhibitory properties of glibenclamide towards various others ABC proteins suggest that this sulphonylurea is a general inhibitor of ABC transporters.

British Journal of Pharmacology (2001) 132, 778–784; doi:10.1038/sj.bjp.0703863
Involvement of both G protein αs and βγ subunits in β‐adrenergic stimulation of vascular L‐type Ca2+ channels
Authors: Viard Patricia , Macrez Nathalie , Mironneau Chantal , Mironneau Jean 
Published: January 2005

Previous data have shown that activation of β3‐adrenoceptors stimulates vascular L‐type Ca2+ channels through a Gαs‐induced stimulation of the cyclic AMP/PKA pathway. The present study investigated whether β‐adrenergic stimulation also uses the Gβγ/PI3K/PKC pathway to modulate L‐type Ca2+ channels in rat portal vein myocytes.
Peak Ba2+ current (IBa) measured using the whole‐cell patch clamp method was maximally increased by application of 10 μM isoprenaline after blockade of β3‐adrenoceptors by 1 μM SR59230A. Under these conditions, the isoprenaline‐induced stimulation of IBa was reversed by ICI‐118551 (a specific β2‐adrenoceptor antagonist) but not by atenolol (a specific β1‐adrenoceptor antagonist). The β2‐adrenoceptor agonist salbutamol increased IBa, an effect which was reversed by ICI‐118551 whereas the β1‐adrenoceptor agonist dobutamine had no effect on IBa.
Application of PKA inhibitors (H‐89 and Rp 8‐Br‐cyclic AMPs) or a PKC inhibitor (calphostin C) alone did not affect the β2‐adrenergic stimulation of IBa whereas simultaneous application of both PKA and PKC inhibitors completely blocked this stimulation.
The β2‐adrenergic stimulation of L‐type Ca2+ channels was blocked by a pre‐treatment with cholera toxin and by intracellular application of an anti‐Gαs antibody (directed against the carboxyl terminus of Gαs). In the presence of H‐89, intracellular infusion of an anti‐Gβcom antibody or a βARK1 peptide as well as a pre‐treatment with wortmannin (a PI3K inhibitor) blocked the β2‐adrenergic stimulation of IBa.
These results suggest that the β2‐adrenergic stimulation of vascular L‐type Ca2+ channels involves both Gαs and Gβγ subunits which exert their stimulatory effects through PKA and PI3K/PKC pathways, respectively.

British Journal of Pharmacology (2001) 132, 669–676; doi:10.1038/sj.bjp.0703864
Mechanism of prolonged vasorelaxation to ATP in the rat isolated mesenteric arterial bed
Authors: Ralevic Vera 
Published: January 2005

This study investigated the mechanism of prolonged relaxation to ATP in the rat isolated perfused mesenteric arterial bed.
In methoxamine pre‐constricted preparations, ATP elicited dose‐dependent, endothelium‐dependent, rapid relaxation at 5 pmol – 0.05 μmol (Rmax 76±5.6%, pD2 9.2±0.2), and contraction, followed by prolonged endothelium‐independent vasorelaxation at 0.05, 0.5 and 5 μmol (56±3.0, 87±2.9 and 85±4.6%). Suramin (100 μM), attenuated rapid (pD2 7.8±0.1) and prolonged relaxation to ATP. The selective P2 receptor antagonist PPADS (10 μM) reduced prolonged, but not rapid relaxation. Neither phase of relaxation was affected by 8‐sulphophenyltheophylline (1 μM) or indomethacin (10 μM).
α,β‐methylene ATP (α,β‐meATP; 10 μM) attenuated prolonged relaxation to ATP (relaxations at 0.05 and 0.5 μmol were 25±8.3 and 48±9.0%, respectively). α,β‐meATP blocked contractions and revealed rapid relaxation to ATP at 0.05 – 5 μmol.
Capsaicin pre‐treatment did not affect either phase of vasorelaxation to ATP. α,β‐meATP (10 μM) had no effect on vasorelaxation mediated by electrical stimulation of capsaicin‐sensitive sensory nerves.
High K+ (25 mM) attenuated prolonged relaxation to ATP (21±2.6 and 64±5.8%, at 0.05 and 0.5 μmol, respectively), but had no effect on rapid relaxation. Ouabain (1 mM), an inhibitor of Na+/K+‐ATPase, and glibenclamide (10 μM), an inhibitor of KATP channels, also attenuated prolonged relaxation to ATP. Charybdotoxin (100 nM), a selective inhibitor of KCa channels, and tetraethylammonium (10 mM) had no effect on rapid or prolonged relaxations.
These results show that the prolonged phase of vasorelaxation to ATP in the rat isolated mesenteric arterial bed, which may be mediated by P2Y receptors, is endothelium‐independent, involves activation of Na+/K+‐ATPase and KATP channels, and is inhibited by α,β‐meATP. Neither prolonged nor rapid vasorelaxation to ATP involves capsaicin‐sensitive sensory nerves, adenosine P1 receptors, prostanoids or KCa channels.

British Journal of Pharmacology (2001) 132, 685–692; doi:10.1038/sj.bjp.0703868
Neuropeotide Y changes the excitability of fine afferent units in the rat knee joint
Authors: Just Stefan , Heppelmann Bernd 
Published: January 2005

The aim of the present study was to examine the effects of the sympathetic co‐transmitter Neuropeotide Y on primary afferent nerve fibres of the rat knee joint. The responses to passive joint rotations at defined torque were recorded from 41 slowly conducting afferent nerve fibres (0.9 – 18.8 m s−1) innervating the knee joint capsule.
About 70% of the joint afferents were significantly affected in their mechanosensitivity by topical application of Neuropeptide Y. Significant effects occurred at a concentration of 10 nM.
Decreased mechanosensitivity was observed in about 40% of nerve fibres, whereas 30% of the units increased the mechanosensitivity. In addition, in about 35% of the fibres resting activity was induced or increased. Neither the conduction velocity nor the mechanical threshold of the units correlated with the described effects of Neuropeptide Y.
NPY(13 – 36), a specific Y2‐receptor agonist, only modulated the mechanosensitivity, with no effect on the resting activity. The effects on the mechanosensitivity were similar to Neuropeptide Y, i.e. increase and decrease of the response.
Studies with the Y1‐agonist (Leu31, Pro34)‐NPY showed that activation of the Y1‐receptor predominantly resulted in an enhanced mechanosensitivity and an induction or increase of a resting activity. The opposite effect was observed by application of BIBP 3226 BS, a Y1‐receptor antagonist.
In conclusion, these data indicate that Neuropeptide Y affects the excitability of sensory nerve fibre endings.

British Journal of Pharmacology (2001) 132, 703–708; doi:10.1038/sj.bjp.0703871
Involvement of protein kinase C in the presynaptic nicotinic modulation of [3H]‐dopamine release from rat striatal synaptosomes
Authors: Soliakov Lev , Wonnacott Susan 
Published: January 2005

Presynaptic nicotinic ACh receptors modulate transmitter release in the brain. Here we report their interactions with protein kinase C (PKC) with respect to [3H]‐dopamine release from rat striatal synaptosomes, monitored by superfusion.
Two specific PKC inhibitors, Ro 31‐8220 (1 μM) and D‐erythro‐sphingosine (10 μM) significantly reduced (by 51 and 26% respectively) [3H]‐dopamine release stimulated by anatoxin‐a (AnTx), a potent and selective agonist of nicotinic ACh receptors. The inactive structural analogue of Ro 31‐8220, bisindolylmaleimide V (1 μM) had no effect.
Two phorbol esters, PDBu (1 μM) and PMA (1 μM) potentiated AnTx‐evoked [3H]‐dopamine release by 50 – 80%. This was Ca2+‐dependent and prevented by PKC inhibitors. In the absence of nicotinic agonist, phorbol esters enhanced basal release through a PKC‐independent mechanism.
A 86Rb+ efflux assay of nicotinic ACh receptor function confirmed that Ro 31‐8220 has no nonspecific effect on presynaptic nicotinic ACh receptors.
These results suggest that PKC is activated by nicotinic ACh receptor stimulation and mediates a component of AnTx‐evoked [3H]‐dopamine release. In addition, independent activation of PKC can further amplify the response, offering a potential mechanism for receptor crosstalk.

British Journal of Pharmacology (2001) 132, 785–791; doi:10.1038/sj.bjp.0703873
Black tea extract, thearubigin fraction, counteract the effects of botulinum neurotoxins in mice
Authors: Satoh Eiki , Ishii Toshiaki , Shimizu Yoshio , Sawamura Shin‐ichi , Nishimura Masakazu 
Published: January 2005

Botulinum neurotoxin type A (BoNT/A, 1.5 nM) completely inhibited indirectly evoked twitches in in vitro mouse phrenic nerve‐diaphragm preparations within 40 – 45 min. Black tea extract, thearubigin fraction (TRB), mixed with BoNT/A blocked the inhibitory effect of the toxin. The protective effect of TRB extended to botulinum neurotoxins types B and E (BoNT/B and BoNT/E) and tetanus toxin, but not to tetrodotoxin. TRB was also effective against oral toxicity of BoNT/A, B and E. Thus, TRB may be of potential benefit in protecting the paralytic actions of botulinum neurotoxins (BoNTs), but its use is limited by mixing with the toxin.British Journal of Pharmacology (2001) 132, 797–798; doi:10.1038/sj.bjp.0703883