bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired IL‐1β‐induced neutrophil accumulation in tachykinin NK1 receptor knockout mice
Authors: Ahluwalia Amrita , De Felipe Carmen , O'Brien John , Hunt Stephen P. , Perretti Mauro 
Published: January 2005

Tachykinin NK1 receptors play an important role in the development of neurogenic inflammatory responses. We have used the murine air‐pouch model to investigate whether the neurogenic component of the cellular inflammatory response to interleukin‐1β (IL‐1β, 10 ng into the air‐pouch) is altered in NK1 receptor knockout mice compared to wild type controls. Air‐pouches were washed following a 4 h IL‐1β treatment, the wash collected and neutrophil number estimated using a Neubauer haemocytometer. The response to IL‐1β was significantly attenuated in NK1 receptor +/− (40% reduction) and −/− mice (62% reduction) compared to wild type controls (+/+), whilst the response to cytokine‐induced neutrophil chemoattractant (CINC, 0.3 μg) was unaffected. The response to substance P (7.5 nmol) was attenuated by approximately 50% in both NK1 receptor +/− and −/− mice compared to wild type controls. In conclusion NK1 receptors play a significant role in the cellular response to IL‐1β in a model of inflammation.British Journal of Pharmacology (1998) 124, 1013–1015; doi:10.1038/sj.bjp.0701978
U937 cells deprived of endogenous annexin 1 demonstrate an increased PLA2 activity
Authors: Solito Egle , Raguenes‐Nicol Celine , De Coupade Catherine , Bisagni‐Faure Anne , Russo‐Marie Françoise 
Published: January 2005

Annexin 1 (An 1), a phospholipid and calcium binding protein, is strongly expressed in differentiated U 937 cells. In attempting to correlate the expression of An 1 with phospholipase A2 (PLA2) activity, U 937 cells were stably transfected both with a Sense and Antisense cDNA for An 1. PLA2 activity was measured by Flow cytometry analysis utilizing the bis‐Bodipy‐C11‐PC fluorescent probe.
U 937 cells stably transfected with the sense or antisense vectors were differentiated for 24 h with phorbol 12‐myristate 13‐acetate (PMA, 6 ng ml−1). Both in undifferentiated and differentiated cells, the Antisense clone (36.4 AS) showed consistently higher PLA2 activity than the control Sense clone (15 S).
Since the fluorescent probe measures the total PLA2 activity, we used two different stimuli, PMA: (100 ng ml−1) or lipopolysaccharide (LPS, 10 ng ml−1), and two different inhibitors, to discriminate the PLA2 involved (namely arachidonyl trifluoromethyl ketone or AACOCF3, which is specific for the cytosolic PLA2, and SB 203347 specific for the secretory PLA2).
In the Antisense clone the inhibitory effect of AACOCF was stronger [68%, P<0.025] than in the Sense, which may reflect the lower endogenous level of An 1 present in the cells. On the contrary, the inhibitory effect of SB 203347 [60% of inhibition] was identical in both clones.
Since cPLA2 activity is correlated with its phosphorylation, Western and shift blot analysis were performed. They did not show any significative difference between the phosphorylated and non phosphorylated form of the enzyme in both the differentiated or not, Sense and Antisense clones. Furthermore the tyrosine phosphorylation analysis of An 1 showed that less than 10% of An 1 was phosphorylated irrespective of PMA presence or absence.
From the pattern of inhibition observed, we propose that the endogenous unphosphorylated form of An 1 may act intracellularly to block the activity of a cytosolic PLA2.

British Journal of Pharmacology (1998) 124, 1675–1683; doi:10.1038/sj.bjp.0701991
Anti‐nociceptive responses produced by human putative counterpart of nocistatin
Authors: Minami Toshiaki , Okuda‐Ashitaka Emiko , Nishiuchi Yuji , Kimura Terutoshi , Tachibana Shinro , Mori Hidemaro , Ito Seiji 
Published: January 2005

b‐nocistatin is a heptadecapeptide produced from bovine prepronociceptin and blocks the induction of hyperalgesia and touch‐evoked pain (allodynia) by intrathecal administration of nociceptin or prostaglandin E2 (PGE2). Human prepronociceptin may generate a 30‐amino acid peptide different in length from b‐nocistatin. Here, we examine whether the human putative counterpart of nocistatin (h‐nocistatin) possessed the same biological activities as b‐nocistatin. Simultaneous intrathecal injection of h‐nocistatin in mice blocked the induction of allodynia by nociceptin and PGE2 in a dose‐dependent manner with ID50 values of 329 pg kg−1 and 16.6 ng kg−1, respectively. h‐nocistatin was about 10 times less potent than b‐nocistatin. h‐nocistatin also attenuated the nociceptin‐ and PGE2‐induced hyperalgesia. These results demonstrate that h‐nocistatin is biologically active and may be involved in the processing of pain at the spinal level in humans.British Journal of Pharmacology (1998) 124, 1016–1018; doi:10.1038/sj.bjp.0701995
Presynaptic and postsynaptic actions of halothane at glutamatergic synapses in the mouse hippocampus
Authors: Kirson Eilon D , Yaari Yoel , Perouansky Misha 
Published: January 2005

Whole‐cell patch‐clamp recordings in adult mouse hippocampal slices were used to test the mechanism by which the volatile anesthetic halothane inhibits glutamate receptor‐mediated synaptic transmission. Non‐N‐methyl‐D‐aspartate (nonNMDA) and NMDA receptor‐mediated currents in CA1 pyramidal cells were pharmacologically isolated by bath application of D,L‐2‐amino‐5‐phosphonovaleric acid (APV; 100 μM) or 6‐cyano‐7‐nitro‐quinoxaline‐2,3‐dione (CNQX; 5 μM), respectively.
Halothane blocked both nonNMDA and NMDA receptor‐mediated excitatory postsynaptic currents (EPSCs) to a similar extent (IC50 values of 0.66 and 0.57 mM, respectively).
Partial blockade of the EPSCs by lowering the extracellular concentration of calcium ([Ca2+]o), but not by application of CNQX (1 μM), was accompanied by an increase in paired‐pulse facilitation (PPF). Halothane‐induced blockade of the EPSCs also was associated with an increase in PPF.
The effects of halothane on α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) and NMDA receptor‐mediated currents induced by agonist iontophoresis, were compared. AMPA‐induced currents were blocked with an IC50 of 1.7 mM. NMDA‐induced currents were significantly less sensitive to halothane (IC50 of 5.9 mM).
The effect of halothane on iontophoretic AMPA dose‐response curves was tested. Halothane suppressed the maximal response to AMPA without affecting its EC50, suggesting a noncompetitive mechanism of inhibition.
All effects of halothane were reversible upon termination of the exposure to the drug.
These data suggest that halothane blocks central glutamatergic synaptic transmission by presynaptically inhibiting glutamate release and postsynaptically blocking the AMPA subtype of glutamate receptors.

British Journal of Pharmacology (1998) 124, 1607–1614; doi:10.1038/sj.bjp.0701996
Characterization of an atypical muscarinic cholinoceptor mediating contraction of the guinea‐pig isolated uterus
Authors: Boxall Donna K , Ford Anthony P D W , Choppin Agnes , Nahorski Stefan R , Challiss R A John , Eglen Richard M 
Published: January 2005

In many smooth muscle tissues a minor M3‐muscarinic acetylcholine (mACh) receptor population mediates contraction, despite the presence of a larger M2‐mACh receptor population. However, this is not the case for guinea‐pig uterus where radioligand binding and functional studies exclude a dominant role for M3‐mACh receptors.
Using tissue from animals pre‐treated with diethylstilboestrol, estimates of antagonist affinity were made before and after selective alkylation procedures, together with estimates of agonist affinity to characterise the mACh receptor population mediating carbachol‐induced contraction of guinea‐pig isolated uterus.
Antagonist affinity estimates made at `protected' receptors were not significantly different from those made in untreated tissues. However all estimations were significantly different from those reported in guinea‐pig ileum and atria. The rank order of affinities were atropine>zamifenacin=tripitramine>methoctramine. Carbachol‐induced contractions were insensitive to the M4‐selective muscarinic toxin MTx‐3, or PD102807 (0.1 μM) ruling out a role for M4‐mACh receptors.
The agonist affinity value for L‐660,863, a putative `M2‐selective' agonist of 5.44±0.30 (n=6) was significantly different from that reported in guinea‐pig atria. In contrast, the pKA value for carbachol (4.22±0.17; n=8) agrees with that reported for guinea‐pig ileum.
Carbachol‐induced contractions were insensitive to pertussis toxin although carbachol‐induced inhibition of forskolin‐stimulated cyclic AMP production was attenuated, ruling out the involvement of Gi‐proteins in contraction.
Radioligand binding studies revealed a KD for N‐[3H]‐methylscopolamine of 0.12±0.05 nM and a Bmax of 147±18 fmol mg protein−1. Antagonist affinity estimates made using competition binding studies supported previous data suggesting the presence of a homogenous population of M2‐mACh receptors.
These data suggest a small population of mACh receptors with an atypical operational profile which can not be distinguished using radioligand binding studies may mediate carbachol‐induced contraction of guinea‐pig isolated uterus.

British Journal of Pharmacology (1998) 124, 1615–1622; doi:10.1038/sj.bjp.0702002
Metabolic response to various β‐adrenoceptor agonists in β3‐adrenoceptor knockout mice: Evidence for a new β‐adrenergic receptor in brown adipose tissue
Authors: Preitner Frédéric , Muzzin Patrick , Revelli Jean‐Pierre , Seydoux Josiane , Galitzky Jean , Berlan Michel , Lafontan Max , Giacobino Jean‐Paul 
Published: January 2005

The β3‐adrenoceptor plays an important role in the adrenergic response of brown and white adipose tissues (BAT and WAT). In this study, in vitro metabolic responses to β‐adrenoceptor stimulation were compared in adipose tissues of β3‐adrenoceptor knockout and wild type mice. The measured parameters were BAT fragment oxygen uptake (MO2) and isolated white adipocyte lipolysis.
In BAT of wild type mice (−)‐norepinephrine maximally stimulated MO2 4.1±0.8 fold. Similar maximal stimulations were obtained with β1‐,β2‐ or β3‐adrenoceptor selective agonists (dobutamine 5.1±0.3, terbutaline 5.3±0.3 and CL 316,243 4.8±0.9 fold, respectively); in BAT of β3‐adrenoceptor knockout mice, the β1‐ and β2‐responses were fully conserved.
In BAT of wild type mice, the β1/β2‐antagonist and β3‐partial agonist CGP 12177 elicited a maximal MO2 response (4.7±0.4 fold). In β3‐adrenoceptor knockout BAT, this response was fully conserved despite an absence of response to CL 316,243. This unexpected result suggests that an atypical β‐adrenoceptor, distinct from the β1‐, β2‐ and β3‐subtypes and referred to as a putative β4‐adrenoceptor is present in BAT and that it can mediate in vitro a maximal MO2 stimulation.
In isolated white adipocytes of wild type mice, (−)‐epinephrine maximally stimulated lipolysis 12.1±2.6 fold. Similar maximal stimulations were obtained with β1‐, β2‐ or β3‐adrenoceptor selective agonists (TO509 12±2, procaterol 11±3, CL 316,243 11±3 fold, respectively) or with CGP 12177 (7.1±1.5 fold). In isolated white adipocytes of β3‐adrenoceptor knockout mice, the lipolytic responses to (−)epinephrine, to the β1‐, β2‐, β3‐adrenoceptor selective agonists and to CGP 12177 were almost or totally depressed, whereas those to ACTH, forskolin and dibutyryl cyclic AMP were conserved.

British Journal of Pharmacology (1998) 124, 1684–1688; doi:10.1038/sj.bjp.0702007
Inhibitors of the activity of poly (ADP‐ribose) synthetase reduce the cell death caused by hydrogen peroxide in human cardiac myoblasts
Authors: Bowes Joanne , Piper Julie , Thiemermann Christoph 
Published: January 2005

Poly (ADP‐ribose) synthetase (PARS) is a nuclear enzyme activated by strand breaks in DNA which are caused by reactive oxygen species (ROS). Inhibitors of PARS activity reduce the degree of reperfusion injury of the heart in vivo and in vitro. Here we investigate the role of PARS in the cell death of human cardiac myoblasts caused by hydrogen peroxide.
Exposure of human cardiac myoblasts to hydrogen peroxide caused a time‐ and concentration‐dependent reduction in mitochondrial respiration (cell injury), an increase in cell death (LDH release), as well as an increase in PARS activity.
The PARS inhibitors 3‐aminobenzamide (3 mM), 1,5‐dehydroxyisoquinoline (300 μM) or nicotinamide (3 mM) attenuated the cell injury and death as well as the increase in PARS activity caused by hydrogen peroxide (3 mM; 4 h for cell injury/death, 60 min for PARS activity) in human cardiac myoblasts. In contrast, the inactive analogues 3‐aminobenzoic acid (3 mM) or nicotinic acid (3 mM) were without effect.
The iron chelator deferoxamine (1–10 mM) caused a concentration‐dependent reduction in the cell injury and death caused by hydrogen peroxide in these human cardiac myoblasts.
Thus, the cell injury/death caused by hydrogen peroxide in human cardiac myoblasts is secondary to the formation of hydroxyl radicals and due to an increase in PARS activity. We therefore propose that activation of PARS contributes to the cell injury/cell death associated with oxidant stress in the heart.

British Journal of Pharmacology (1998) 124, 1760–1766; doi:10.1038/sj.bjp.0702009
L‐687,414, a low efficacy NMDA receptor glycine site partial agonist in vitro, does not prevent hippocampal LTP in vivo at plasma levels known to be neuroprotective
Authors: Priestley Tony , Marshall George R , Hill Raymond G , Kemp John A 
Published: January 2005

N‐methyl‐D‐aspartic acid (NMDA) receptors are known to play a key role in the induction phase of long‐term potentiation (LTP) at certain hippocampal synapses and to represent some component of spatial learning in animals. The ability of NMDA receptor antagonists (or gene knockout) to impair LTP has led to the suggestion that the therapeutic use of such antagonists may impair cognitive function in humans. The present study compares the effects on LTP of NMDA receptor ion channel block by MK‐801 and glycine‐site antagonism by 3R(+)cis‐4‐methyl‐pyrrollid‐2‐one (L‐687,414).
In vitro experiments using rat cortical slices revealed L‐687,414 to be ∼3.6 fold more potent than its parent analogue, R(+)HA‐966 at antagonizing NMDA‐evoked population depolarizations (apparent Kbs: 15 μM and 55 μM, respectively).
Whole‐cell voltage‐clamp experiments using rat cultured cortical neurones revealed L‐687,414 to shift to the right the concentration‐response relationship for NMDA‐evoked inward current responses (pKb=6.2±0.12). L‐687,414 affinity for the glycine site on the NMDA receptor complex was also determined from concentration‐inhibition curves, pKi=6.1±0.09. In the latter experiments, L‐687,414 and R(+)HA‐966 were unable to completely abolish inward current responses suggesting each compound to be a low efficacy partial agonist (estimated intrinsic activity=∼10 and 20% of glycine, respectively).
L‐687,414 and MK‐801 were compared for their effects on NMDA receptor‐dependent LTP in the dentate gyrus of anaethestized rats following high frequency stimulation of the medial perforant path (mPP) afferents. Control rats, administered saline (0.4 ml kg−1 followed by 0.0298 ml min−1), showed a robust augmentation of the population e.p.s.p. risetime (LTP) recorded in the dentate hilus following tetanic stimulation of the mPP. LTP was effectively abolished in a separate group of rats treated with an MK‐801 dosing regimen (0.12 mg kg−1 i.v. followed by 1.8 μg kg−1 h−1) known to produce maximal neuroprotection in a rat stroke model but, by contrast, remained largely intact in a third group of animals given a similarly neuroprotective L‐687,414 treatment (28 mg kg−1 i.v. followed by 28 mg kg−1 h−1).
These experiments suggest that a low level of intrinsic activity at the glycine site may be sufficient to support NMDA receptor‐dependent LTP but in circumstances where there is likely to be an excessive NMDA receptor activation the agonism associated with a low efficacy partial agonist, such as L‐687,414, is dominated by the antagonist properties. Thus, an NMDA receptor partial agonist profile may offer a therapeutic advantage over neutral antagonists by permitting an acceptable level of `normal' synaptic transmission whilst curtailing excessive receptor activation.

British Journal of Pharmacology (1998) 124, 1767–1773; doi:10.1038/sj.bjp.0702010
Flunitrazepam rapidly reduces GABAA receptor subunit protein expression via a protein kinase C‐dependent mechanism
Authors: Johnston Jonathan D. , Price Sally A. , Bristow David R. 
Published: January 2005

Acute flunitrazepam (1 μm) exposure for 1 h reduced GABAA receptor α1 (22±4%, mean±s.e.mean) and β2/3 (21±4%) subunit protein levels in cultured rat cerebellar granule cells. This rapid decrease in subunit proteins was completely prevented by bisindolymaleimide 1 (1 μm), an inhibitor of protein kinase C, but not by N‐[2‐((p‐bromocinnamyl)amino)ethyl]‐5‐isoquinolinesulfonamide (H‐89, 4.8 μm), an inhibitor of protein kinases A and G. These results suggest the existence of a benzodiazepine‐induced mechanism to rapidly alter GABAA receptor protein expression, that appears to be dependent on protein kinase C activity.British Journal of Pharmacology (1998) 124, 1338–1340; doi:10.1038/sj.bjp.0702012
Action potential shortening through the putative β4‐adrenoceptor in ferret ventricle: comparison with β1‐ and β2‐adrenoceptor‐mediated effects
Authors: Lowe Martin D. , Grace Andrew A. , Vandenberg Jamie I. , Kaumann Alberto J. 
Published: January 2005

The electrophysiological responses to (−)‐CGP 12177 ((−)‐4‐(3‐tertiarybutylamino‐2‐hydroxypropoxy) benzimidazol‐2‐one), an agonist for the putative β4‐adrenoceptor, were investigated on isolated perfused ferret hearts paced at 100 min−1 and compared to those of (−)‐noradrenaline and (−)‐adrenaline, mediated through β1‐ and β2‐adrenoceptors respectively. The three agonists decreased ventricular monophasic action potential duration but prolonged the action potential plateau; β3‐adrenoceptor‐selective agonists had no effect. (−)‐CGP 12177 was the most potent, but (−)‐noradrenaline the most efficacious; both agonists caused ventricular extra‐systoles. Because only (−)‐noradrenaline but not (−)‐CGP 12177 elicited shortening of the refractory period, the mechanism of arrhythmias mediated through β1‐ and putative β4‐adrenoceptors may be different.British Journal of Pharmacology (1998) 124, 1341–1344; doi:10.1038/sj.bjp.0702013
Analgesic and sedative concentrations of lignocaine shunt tonic and burst firing in thalamocortical neurones
Authors: Schwarz Stephan K W , Puil Ernest 
Published: January 2005

The effects of lignocaine [lidocaine] HCl (0.6 μM–1 mM) on the membrane electrical properties and action potential firing of neurones of the ventral posterolateral (VPL) nucleus of the thalamus were investigated using whole cell recording techniques in rat brain slices in vitro.
Bath application of lignocaine reversibly decreased the input resistance (Ri) of VPL neurones. This effect was observed at low, clinically sedative and analgesic concentrations (i.e., maximal amplitude at 10 μM) whereas higher concentrations (300 μM–1 mM) had no effect on Ri.
Lignocaine (10–100 μM) depolarized VPL neurones up to 14 mV in a reversible manner.
Consistent with a decreased Ri, low concentrations of lignocaine shunted the current required for spike generation in the tonic pattern. Lignocaine increased the threshold amplitude of current required for firing and decreased the tonic firing frequency, without concomitant elevation of the voltage threshold for firing or reduction in the maximal rate of rise (dV/dtmax) of spikes.
Low concentrations of lignocaine shunted low threshold spike (LTS) burst firing evoked either from hyperpolarized potentials or as rebound bursts on depolarization from prepulse‐conditioned potentials.
Higher concentrations of lignocaine (300 μM–1 mM), not associated with a decrease in Ri, elevated the voltage threshold for firing and reduced the dV/dtmax of spikes in a concentration‐dependent fashion.
In conclusion, low concentrations of lignocaine shunted tonic and burst firing in VPL neurones by decreasing Ri, a mechanism not previously described for local anaesthetics in the CNS. We suggest that a decreased resistance in thalamocortical neurones contributes to the sedative, analgesic, and anaesthetic properties of systemic lignocaine in vivo.

British Journal of Pharmacology (1998) 124, 1633–1642; doi:10.1038/sj.bjp.0702015
Alternative pathways of angiotensin II production in the human saphenous vein
Authors: Borland Julie A A , Chester Adrian H , Morrison Karen A , Yacoub Magdi H 
Published: January 2005

The aim of our study was to demonstrate the existence, location and functional importance of an alternative angiotensin II‐forming pathway other than angiotensin converting enzyme (ACE) in the human saphenous vein (SV).
Vascular reactivity studies using an in vitro organ bath technique showed that the SV (n=20) produced similar maximum contractions in response to angiotensin I (41.5±5.4 mN) compared to those observed to angiotensin II (46.7±10.9 mN). The response to angiotensin I could be significantly inhibited (P<0.05) by incubation with the AT1 receptor antagonist losartan (1 μM).
Prior incubation of segments of SV with either captopril (1 μM) (n=6), quinaprilat (1 μM) (n=7), or the chymase inhibitor soya bean trypsin inhibitor (SBTI) (10 μM) (n=7) singularly failed to have any inhibitory effect on the response to angiotensin I. However when vessel segments (n=7) were co‐incubated with quinaprilat (1 μM) and SBTI (10 μM), the SV exhibited a rightward shift in curve profile to angiotensin I and a markedly reduced maximum response 12.5±2.4 mN, when compared to control (30.4±7.6 mN), quinaprilat (24.5±9.4 mN), and SBTI (31.6±10.7 mN) on their own.
An immunohistochemical technique employing streptavidin biotin peroxidase localised ACE to both endothelial cells and smooth muscle cells while chymase was confined to mast cells in the adventitia of the vessel wall.
In conclusion, our results demonstrate the existence of an alternative angiotensin I converting pathway to that of ACE, involving chymase. Therefore, there is the capacity for a continuation of angiotensin II formation. in the presence of ACE inhibition.

British Journal of Pharmacology (1998) 125, 423–428; doi:10.1038/sj.bjp.0702018