bluuebunny/crossref_metadata_2025_split huggingface dataset:
Involvement of the NH2 terminal domain of catecholamine transporters in the Na+ and Cl−‐dependence of a [3H]‐dopamine uptake
Authors: Syringas Maria , Janin François , Giros Bruno , Costentin Jean , Bonnet Jean‐Jacques 
Published: January 2005

The ionic dependence of the [3H]‐dopamine uptake was studied in transfected cells expressing the human neuronal transporter for dopamine (hDAT) or noradrenaline (hNET), and chimeric transporters resulting from the symmetrical exchange of the region from the NH2 terminal through the first two transmembrane domains (cassette I). Chimera A is formed by hDAT comprising cassette I from hNET, whereas chimera B corresponds to the reverse construct.
The appearance or the intensity of a Cl−‐independent component of transport was linked to the presence of the COOH terminal part of hNET in both monoclonal and polyclonal Ltk− cells (Cl− substituted by isethionate and NO3−, respectively), and in transiently transfected COS‐7 cells.
Cassette I was also involved in the Cl−‐dependence because the transport activity of polyclonal Ltk− cells expressing A was partly Cl−‐independent and because Ltk− cells expressing transporters containing cassette I of hDAT displayed higher KmCl− values than cells expressing the reverse constructs.
In monoclonal Ltk− cell lines, KmNa+ values and biphasic vs monophasic dependence upon Na+ concentrations differentiate transporters containing cassette I of hNET from those containing cassette I of hDAT. In COS‐7 cells, the exchange of cassette I produced a significant change in Hill number values.
In Na+‐dependence studies, exchange of the COOH terminal part significantly modified Hill number values in both Ltk− and COS‐7 cells.
Hill number values close to two were found for hNET and hDAT when sucrose was used as substitute for NaCl.
The NH2 terminal part of the transporters bears some of the differences in the Na+ and Cl−‐dependence of the uptake that are observed between hDAT and hNET. Present results also support a role of the COOH terminal part in the ionic dependence.

British Journal of Pharmacology (2001) 133, 387–394; doi:10.1038/sj.bjp.0704097
Ergolide, sesquiterpene lactone from Inula britannica, inhibits inducible nitric oxide synthase and cyclo‐oxygenase‐2 expression in RAW 264.7 macrophages through the inactivation of NF‐κB
Authors: Whan Han Jeung , Gon Lee Byeong , Kee Kim Yong , Woo Yoon Jong , Kyoung Jin Hye , Hong Sungyoul , Young Lee Hoi , Ro Lee Kang , Woo Lee Hyang 
Published: January 2005

We investigated the mechanism of suppression of inducible nitric oxide synthase (iNOS) and cyclo‐oxygenase‐2 (COX‐2) by ergolide, sesquiterpene lactone from Inula britannica.
iNOS activity in cell‐free extract of LPS/IFN‐γ‐stimulated RAW 264.7 macrophages was markedly attenuated by the treatment with ergolide. Its inhibitory effect on iNOS was paralleled by decrease in nitrite accumulation in culture medium of LPS/IFN‐γ‐stimulated RAW 264.7 macrophages in a concentration‐dependent manner. However, its inhibitory effect does not result from direct inhibition of the catalytic activity of NOS.
Ergolide markedly decreased the production of prostaglandin E2 (PGE2) in cell‐free extract of LPS/IFN‐γ‐stimulated RAW 264.7 macrophages in a concentration‐dependent manner, without alteration of the catalytic activity of COX‐2 itself.
Ergolide decreased the level of iNOS and COX‐2 protein, and iNOS mRNA caused by stimulation of LPS/IFN‐γ in a concentration‐dependent manner, as measured by Western blot and Northern blot analysis, respectively.
Ergolide inhibited nuclear factor‐κB (NF‐κB) activation, a transcription factor necessary for iNOS and COX‐2 expression in response to LPS/IFN‐γ. This effect was accompanied by the parallel reduction of nuclear translocation of subunit p65 of NF‐κB as well as IκB‐α degradation. In addition, these effects were completely blocked by treatment of cysteine, indicating that this inhibitory effect of ergolide could be mediated by alkylation of NF‐κB itself or an upstream molecule of NF‐κB.
Ergolide also directly inhibited the DNA‐binding activity of active NF‐κB in LPS/IFN‐γ‐pretreated RAW 264.7 macrophages.
These results demonstrate that the suppression of NF‐κB activation by ergolide might be attributed to the inhibition of nuclear translocation of NF‐κB resulted from blockade of the degradation of IκB and the direct modification of active NF‐κB, leading to the suppression of the expression of iNOS and COX‐2, which play important roles in inflammatory signalling pathway.

British Journal of Pharmacology (2001) 133, 503–512; doi:10.1038/sj.bjp.0704099
Regional haemodynamic responses to the cannabinoid agonist, WIN 55212‐2, in conscious, normotensive rats, and in hypertensive, transgenic rats
Authors: Gardiner S M , March J E , Kemp P A , Bennett T 
Published: January 2005

Regional haemodynamic responses to the cannabinoid agonist, WIN 55212‐2 (5 – 250 μg kg−1 i.v.) were assessed in conscious, normotensive, Hannover, Sprague‐Dawley (HSD) rats, and in hypertensive, transgenic ((mRen‐2)27) (abbreviated to TG) rats.
In HSD rats, WIN 55212‐2 caused pressor, and renal and mesenteric vasoconstrictor effects, with a hindquarters vasodilator effect occurring only at the highest dose. In TG rats, the effects of the cannabinoid agonist were qualitatively similar to those seen in HSD rats, except there was no hindquarters vasodilatation.
In both strains of rat, in the presence of losartan, pentolinium and a vasopressin (V1‐receptor) antagonist, the pressor and vasoconstrictor effects of WIN 55212‐2 were abolished, but the hindquarters vasodilator response was enhanced (HSD rats) or was seen only in that circumstance (TG rats). Under these conditions, both strains of rat showed a modest fall in blood pressure, together with mesenteric vasodilatation.
In additional experiments in normotensive SD rats from Charles River (CRSD), it was shown that, in the presence of the V1‐receptor antagonist alone, or losartan alone, or the two antagonists together, the cardiovascular effects of WIN 55212‐2 (50 or 150 μg kg−1) were not attenuated. Hence, the effects described above were likely due to pentolinium.
There were no consistent differences between HSD and TG rats in their haemodynamic responses to methoxamine or noradrenaline, indicating the two strains were not likely to differ markedly in their responsiveness to any putative sympathetic activation induced by WIN 55212‐2.
Collectively, the results indicate that the predominant cardiovascular effects of WIN 55212‐2 in conscious HSD and TG rats (i.e., pressor and vasoconstrictor actions) can be attributed largely to indirect, pentolinium‐sensitive mechanisms, which appear to differ little in the normotensive and hypertensive state, at least in conscious animals. Under the conditions of our experiments, signs of cannabinoid‐induced vasodilatation were modest.

British Journal of Pharmacology (2001) 133, 445–453; doi:10.1038/sj.bjp.0704100
Platelet‐activating factor and endotoxin activate CCAAT/enhancer binding protein in rat small intestine
Authors: Wang Hao , Qu Xiaowu , De Plaen Isabelle G , Hsueh Wei 
Published: January 2005

The transcription factor family CCAAT/enhancer binding proteins (C/EBP) is involved in inflammation via the regulation of the gene expression of various pro‐inflammatory cytokines and proteins. PAF and endotoxin (lipopolysaccharide, LPS) are known agents causing intestinal inflammation and injury. In this study, we examined the binding activity of C/EBP isoforms in rat small intestine in response to PAF (1.5 μg kg−1, i.v.) or LPS (5 mg kg−1, i.v.).
We found that C/EBP is constitutively active in normal small intestine, mainly as C/EBP‐α and β (C/EBP‐β>α). Both C/EBP‐α and β are localized in the intestinal epithelial cells: C/EBP‐α mainly in the crypts, and C/EBP‐β in both villi and crypts, as well as in some lamina propria cells. Only minute amounts of C/EBP‐δ were found.
PAF rapidly upregulates the binding activity of C/EBP‐α and β within 30 min. The increase in C/EBP‐α is prominent in the crypt cells, whereas the change of C/EBP‐β is more widespread. LPS also increases the binding activity of C/EBP‐α and β, and the response is slower than PAF. PAF synergizes with LPS to markedly activate all three subunits. The increase in C/EBP‐α is transient, whereas the other two have a sustained elevation until 120 min.
After challenge with PAF (but not LPS), small amounts of nuclear factor ‐κB (NF‐κB) p50 and p65 subunits are found in the C/EBP‐DNA binding complex, indicating cross‐dimerization of the two transcription families. Pretreatment of rats with pyrrolidine dithiocarbamate (PDTC) suppresses LPS‐, but not PAF‐, induced NF‐κB and C/EBP binding activity, and significantly increases the C/EBP‐δ subunit in LPS‐ or PAF‐induced C/EBP complex.
These results suggest that PAF and LPS activate intestinal C/EBP in vivo, probably via different pathways.

British Journal of Pharmacology (2001) 133, 713–721; doi:10.1038/sj.bjp.0704102
Nitric oxide‐ and nitric oxide donors‐induced relaxation and its modulation by oxidative stress in piglet pulmonary arteries
Authors: López‐López José Gustavo , Pérez‐Vizcaíno Francisco , Cogolludo Angel L , Ibarra Manuel , Zaragozá‐Arnáez Francisco , Tamargo Juan 
Published: January 2005

Inhaled nitric oxide (iNO) is widely used in the treatment of pulmonary hypertension while inhaled NO donors have been suggested as an alternative therapy. The differential susceptibility to inactivation by oxidative stress and oxyhaemoglobin of NO and two NO donors, sodium nitroprusside (SNP) and S‐nitroso‐N‐acetyl‐penicillamine (SNAP) were analysed in isolated endothelium‐denuded pulmonary arteries from 2‐week‐old piglets stimulated with U46619.
NO, SNAP and SNP relaxed the arteries (pIC30=7.73±0.12, 7.26±0.17 and 6.43±0.13, respectively) but NO was not detected electrochemically in the bath after the addition of SNP and only at concentrations at which SNAP produced more than 50% relaxation.
The sGC inhibitor ODQ (10−6 M) or the sarcoplasmic Ca2+‐ATPase thapsigargin (2×10−6 M) markedly inhibited the relaxation induced by NO, SNAP and SNP.
Addition of oxyhaemoglobin (3×10−7 M) or diethyldithiocarbamate (1 mM) markedly inhibited NO‐ (pIC30=6.88±0.07 and 6.92±0.18, respectively), weakly inhibited SNAP‐ and had no effect on SNP‐induced relaxation. Xanthine oxidase (5 mu ml−1) plus hypoxanthine (10−4 M) markedly inhibited NO‐ (pIC30=6.96±0.12) but not SNAP‐ or SNP‐induced relaxation.
Superoxide dismutase (SOD), MnCl2, diphenileneiodonium and exposing the luminal surface of the rings outwards (inversion) potentiated the relaxant responses of NO (pIC30=8.52±0.16, 8.23±0.11, 8.01±0.11 and 8.20±0.10, respectively). However, SOD did not modify the NO detected by the electrode and had no effect on SNAP‐ or SNP‐induced relaxation.
Therefore, the kinetics and local distribution of NO release of NO donors influence the susceptibility to the scavenging effects of oxyhaemoglobin and superoxide.

British Journal of Pharmacology (2001) 133, 615–624; doi:10.1038/sj.bjp.0704103
Pharmacological discrimination between effects of carbamazepine on hippocampal basal, Ca2+‐ and K+‐evoked serotonin release
Authors: Kawata Yuko , Okada Motohiro , Murakami Takuya , Kamata Akihisa , Zhu Gang , Kaneko Sunao 
Published: January 2005

To elucidate mechanisms of hippocampal serotonin release and possible mechanisms of clinical action of carbamazepine (CBZ), we determined interaction between antagonists of N‐type (ω‐conotoxin GVIA:GVIA), P‐type (ω‐agatoxin IVA:IVA) Ca2+ channels, Na+ channel (tetrodotoxin: TTX) and CBZ on hippocampal basal, Ca2+‐ and K+‐evoked serotonin releases, using microdialysis in freely moving rats.
Basal release was reduced by TTX, GVIA and IVA (GVIA>IVA). Ca2+‐evoked release was reduced by GVIA but unaffected by TTX and IVA. K+‐evoked release was reduced by TTX, GVIA and IVA (GVIA<IVA).
TTX inhibited actions of IVA and GVIA on respective basal and K+‐evoked releases, without affecting Ca2+‐evoked release.
Perfusion with 100 μM CBZ (estimated‐concentration in hippocampal tissue: 19±2 μM) enhanced basal and Ca2+‐evoked releases, but reduced K+‐evoked release, whereas 1000 μM CBZ (estimated‐concentration in hippocampal tissue: 188±16 μM) reduced three types of releases.
Under condition of pretreatment with 100 and 1000 μM CBZ, TTX unaffected basal and K+‐evoked releases. Under condition of pretreatment with 100 μM CBZ, IVA and GVIA unaffected basal and K+‐evoked releases, respectively, but GVIA reduced basal, Ca2+‐evoked releases and IVA also reduced K+‐evoked release. Under condition of pretreatment with 1000 μM CBZ, GVIA unaffected three types of releases, and IVA unaffected basal release but reduced K+‐evoked release.
These findings contribute towards the possible mechanisms of concentration‐dependent antiepileptic action of CBZ, which possibly inhibits Na+ channel related neurotransmitter release mechanisms during K+‐evoked stage, and simultaneously enhances N‐type Ca2+ channel related basal serotonin release at the resting stage.

British Journal of Pharmacology (2001) 133, 557–567; doi:10.1038/sj.bjp.0704104
Differential cardiovascular responses to blockade of nNOS or iNOS in rostral ventrolateral medulla of the rat
Authors: Chan Samuel H H , Wang Ling‐Lin , Wang Shu‐Huei , Chan Julie Y H 
Published: January 2005

We investigated the contribution of neuronal or inducible nitric oxide synthase (nNOS or iNOS) at the rostral ventrolateral medulla (RVLM) to central cardiovascular regulation by endogenous nitric oxide (NO), using Sprague‐Dawley rats anaesthetized and maintained with propofol.
Microinjection bilaterally into the RVLM of a NO trapping agent, carboxy‐2‐phenyl‐4,4,5,5‐tetramethylimidazoline‐l‐oxy‐l‐3‐oxide (10, 50 or 100 nmoles) resulted in significant hypotension and bradycardia.
Similar application of a selective antagonist of nNOS, 7‐nitroindazole (1, 2.5 or 5 pmoles), or selective antagonists of iNOS, aminoguanidine (125, 250 or 500 pmoles), N6‐(l‐iminoethyl)‐L‐lysine (250 pmoles) or S‐methylisothiourea (250 pmoles), induced respectively a reduction or an enhancement in systemic arterial pressure, heart rate and power density of the vasomotor components in the spectrum of arterial blood pressure signals, the experimental index for sympathetic neurogenic vasomotor tone.
Both hypotension and bradycardia induced by the NO precursor, L‐arginine (100 nmoles), were significantly blunted when aminoguanidine (250 pmoles) was co‐microinjected bilaterally into the RVLM. On the other hand, co‐administered 7‐nitroindazole (2.5 pmoles) was ineffective.
Whereas low doses of S‐nitro‐N‐acetylpenicillamine (0.25 or 0.5 nmoles) elicited hypertension and tachycardia, high doses of this non‐nitrate NO donor (5 nmoles) induced hypotension and bradycardia.
Reverse transcription – polymerase chain reaction analysis revealed that both iNOS and nNOS mRNA were expressed in the ventrolateral medulla.
We conclude that the prevalence of nNOS over iNOS activity at the RVLM and the associated dominance of sympathoexcitation over sympathoinhibition may underlie the maintenance of sympathetic vasomotor outflow and stable systemic arterial pressure by the endogenous NO.

British Journal of Pharmacology (2001) 133, 606–614; doi:10.1038/sj.bjp.0704105
Role of protein kinase C in the reduction of infarct size by N‐methyl‐1‐deoxynojirimycin, an α‐1,6‐glucosidase inhibitor
Authors: Arai Masazumi , Minatoguchi Shinya , Kumada Hirokazu , Uno Yoshihiro , Nishida Yoshio , Hashimoto Kazuaki , Wang Ningyuan , Takemura Genzou , Fujiwara Takako , Higashioka Masaya , Kuwano Keiichi , Fujiwara Hisayoshi 
Published: January 2005

Preischaemic treatment with N‐methyl‐1‐deoxynojirimycin (MOR‐14), an α‐1,6‐glucosidase inhibitor, attenuates glycogenolysis and lactate accumulation during ischaemia and markedly reduces infarct size in rabbit hearts. In the present study, we have investigated whether protein kinase C (PKC), a principal mediator of ischaemic preconditioning, is also involved in the cardioprotective effect of MOR‐14.
To assess the effect of PKC inhibition on infarct size in MOR‐14‐treated hearts, 38 rabbits were subjected to 30 min of ischaemia followed by 48 h of reperfusion. Infarct size, as a per cent of area at risk, was significantly smaller in rabbits administered 100 mg kg−1 of MOR‐14 10 min before ischaemia (17±2%, n=10), than in a control group (46±5%, n=10). This beneficial effect of MOR‐14 was abolished when 5 mg kg−1 of chelerythrine, a PKC inhibitor, was given 10 min prior to MOR‐14 injection (39±4%, n=10), although chelerythrine alone did not alter infarct size (43±4%, n=8). Further, chelerythrine had no effect on MOR‐14‐induced attenuation of glycogen breakdown and lactate accumulation in hearts excised at 30 min of ischaemia.
Immunoblot analysis of PKC in homogenates of Langendorff‐perfused rabbit hearts revealed that MOR‐14 significantly increased levels of PKC‐ε in the particulate fraction at 20 and 30 min of ischaemia and in the cytosolic fraction at 30 min of ischaemia.
Taken as a whole, our data suggest that PKC acts downstream of the inhibition of glycogenolysis by MOR‐14 to reduce infarct size. Thus, activation of PKC is a more direct mediator of the cardioprotection afforded by MOR‐14 than is inhibition of glycogenolysis.

British Journal of Pharmacology (2001) 133, 635–642; doi:10.1038/sj.bjp.0704107
Tolbutamide stimulation of pancreatic β‐cells involves both cell recruitment and increase in the individual Ca2+ response
Authors: Jonkers Françoise C , Guiot Yves , Rahier Jacques , Henquin Jean‐Claude 
Published: January 2005

Individual pancreatic β‐cells are functionally heterogeneous. Their sensitivity to glucose is variable, so that the proportion of active cells increases with the glucose concentration (recruitment).
We have investigated whether sulphonylureas also recruit β‐cells, by measuring cytoplasmic Ca2+ ([Ca2+]i) – the triggering signal of insulin secretion – in single cells and clusters of cells prepared from mouse islets.
In 4 mM glucose, the threshold concentration of tolbutamide inducing a [Ca2+]i rise was variable (5 – 50 μM). The proportion of responsive cells and clusters therefore increased with the tolbutamide concentration, to reach a maximum of 90% of the cells and 100% of the clusters. This recruitment occurred faster when the glucose concentration was increased from 4 to 5 mM (EC50 of ∼14 and ∼4 μM tolbutamide respectively).
Within responsive clusters little recruitment was observed; when a cluster was active, all or nearly all cells were active probably because of cell coupling. Thus, tolbutamide‐induced [Ca2+]i oscillations were synchronous in all cells of each cluster, whereas there was no synchrony between clusters or individual cells.
Independently of cell recruitment, tolbutamide gradually augmented the magnitude of the [Ca2+]i rise in single cells and clusters. This increase occurred over a broader range of concentrations than did recruitment (EC50 of ∼50 and 25 μM tolbutamide at 4 and 5 mM glucose respectively).
Tolbutamide (10 μM) accelerated the recruitment of single cells and clusters brought about by increasing glucose concentrations (range of 3 – 7 mM instead of 4 – 10 mM glucose), and potentiated the amplification of the individual responses that glucose also produced.
In conclusion, both metabolic (glucose) and pharmacologic (sulphonylurea) inhibition of K+‐ATP channels recruits β‐cells to generate a [Ca2+]i response. However, the response is not of an all‐or‐none type; it increases in amplitude with the concentration of either glucose or tolbutamide.

British Journal of Pharmacology (2001) 133, 575–585; doi:10.1038/sj.bjp.0704108
The effects of flecainide on ATP‐sensitive K+ channels in pig urethral myocytes
Authors: Yunoki Takakazu , Teramoto Noriyoshi , Naito Seiji , Ito Yushi 
Published: January 2005

The effects of the antiarrhythmic drug flecainide on levcromakalim‐induced hyperpolarization, macroscopic and unitary K+ currents in pig urethra were investigated using patch‐clamp techniques. The effects of flecainide were also examined on currents in inside‐out patches of COS7 cells expressing carboxy terminus truncated inwardly rectifying K+ channel (Kir6.2) subunits (i.e. Kir6.2ΔC36) which form ATP‐sensitive K+ channels (KATP channels).
In current‐clamp mode, application of flecainide (100 μM) caused a significant depolarization after the membrane potential had been hyperpolarized by levcromakalim.
In voltage‐clamp experiments, the levcromakalim‐induced outward current was suppressed by 300 μM flecainide in quasi‐physiological K+ conditions (Ki=51 μM). In contrast, approximately 20% of the levcromakalim‐induced inward current still remained even after application of 300 μM flecainide in symmetrical 140 mM K+ conditions (Ki=51 μM). In contrast, approximately 20% of the levcromakalim‐induced inwar=126 μM).
In cell‐attached configuration, the channel activity of the levcromakalim‐induced KATP channels was reversibly inhibited by flecainide (30 μM) at −50 mV. Their activity was also suppressed by either disopyramide or cibenzoline.
Flecainide reversibly inhibited the channel activity of Kir6.2ΔC36 expressed in COS7 cells using inside‐out configuration.
Inhibitory effects of flecainide on the levcromakalim‐induced currents became more potent when the value of external pH increased, although this slightly reduced the proportion of drug molecules carrying a positive charge.
These results suggest that flecainide inhibits channel activity through blocking the pore site of the KATP channel in pig urethra.

British Journal of Pharmacology (2001) 133, 730–738; doi:10.1038/sj.bjp.0704109
Straight‐chain alcohols exhibit a cutoff in potency for the inhibition of recombinant glutamate receptor subunits
Authors: Akinshola B Emmanuel 
Published: January 2005

The effects of n‐alcohols (methanol to 1‐decanol) on kainate‐activated AMPA receptor subunit GluR1 and GluR3 ion currents were studied in Xenopus oocytes using the two‐electrode voltage‐clamp recording technique.
For short‐chain alcohols from methanol to 1‐hexanol, potency for inhibition of GluR1 and GluR3 receptor‐mediated current increased in proportion to the chain length or hydrophobicity of the alcohol.
The IC50 values of these alcohols for GluR1 were: methanol, 702 mM; ethanol, 170 mM; 1‐propanol, 69 mM; 1‐butanol, 20 mM; 1‐pentanol, 17 mM; and 1‐hexanol, 10 mM. For GluR3, IC50 values were: methanol, 712 mM; ethanol, 238 mM; 1‐propanol, 50 mM; 1‐butanol, 32 mM; 1‐pentanol, 13 mM; and 1‐hexanol, 7 mM.
For long‐chain alcohols, 1‐heptanol was less potent than 1‐hexanol (estimated IC50: 19 mM for GluR1 and 18 mM for GluR3), 1‐octanol had little effect only on GluR3, and 1‐nonanol and 1‐decanol did not significantly inhibit both GluR1 and GluR3 responses.
The observations indicate that straight‐chain n‐alcohols exhibit a cutoff in their potency for inhibition of the function of non‐NMDA glutamate receptor subunits, GluR1 and GluR3. The cutoff in potency of n‐alcohols for inhibition of non‐NMDA glutamate receptor function is consistent with the interpretation that alcohols affect the function of these receptor‐channels by interacting with an alcohol binding site of specific dimensions on the receptor protein.

British Journal of Pharmacology (2001) 133, 651–658; doi:10.1038/sj.bjp.0704112