bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinction between surmountable and insurmountable selective AT1 receptor antagonists by use of CHO‐K1 cells expressing human angiotensin II AT1 receptors
Authors: Vanderheyden P M L , Fierens F L P , De Backer J P , Fraeyman N , Vauquelin G 
Published: January 2005

CHO‐K1 cells that were stably transfected with the gene for the human AT1 receptor (CHO‐AT1 cells) were used for pharmacological studies of non‐peptide AT1 receptor antagonists.
In the presence of 10 mM LiCl, angiotensin II caused a concentration‐dependent and long‐lasting increase of inositol phosphates accumulation with an EC50 of 3.4 nM. No angiotensin II responses are seen in wild‐type CHO‐K1 cells.
[3H]‐Angiotensin II bound to cell surface AT1 receptors (dissociates under mild acidic conditions) and is subject to rapid internalization.
Non‐peptide selective AT1 antagonists inhibited the angiotensin II (0.1 μM) induced IP accumulation and the binding of [3H]‐angiotensin II (1 nM) with the potency order: candesartan > EXP3174 > irbesartan > losartan. Their potencies are lower in the presence of bovine serum albumin.
Preincubation with the insurmountable antagonist candesartan decreased the maximal angiotensin II induced inositol phosphate accumulation up to 94% and, concomitantly, decreased the maximal binding capacity of the cell surface receptors. These inhibitory effects were half‐maximal for 0.6 nM candesartan and were attenuated by simultaneous preincubation with 1 μM losartan indicating a syntopic action of both antagonists.
Losartan caused a parallel rightward shift of the angiotensin II concentration‐response curves and did not affect the maximal binding capacity. EXP3174 (the active metabolite of losartan) and irbesartan showed a mixed‐type behavior in both functional and binding studies.
Reversal of the inhibitory effect was slower for candesartan as compared with EXP3174 and irbesartan and it was almost instantaneous for losartan, suggesting that the insurmountable nature of selective AT1 receptor antagonists in functional studies was related to their long‐lasting inhibition.

British Journal of Pharmacology (1999) 126, 1057–1065; doi:10.1038/sj.bjp.0702398
Actions of 3‐[2′‐phosphonomethyl[1,1′‐biphenyl]‐3‐yl]alanine (PMBA) on cloned glycine receptors
Authors: Hosie Alastair M , Akagi Hiroyuki , Ishida Michiko , Shinozaki Haruhiko 
Published: January 2005

PMBA is a novel antagonist of strychnine‐sensitive glycine receptors in the rat spinal cord, however, its mode of action is unknown. The actions of PMBA on rat glycine receptor α1 and α2 homomers in Xenopus oocytes were studied under two‐electrode voltage‐clamp.
Co‐application of PMBA and glycine to both α1 and α2 homomers yielded inward currents which decayed to a steady‐state. Responses rose slowly to the same steady‐state amplitude following a 2 min pre‐incubation in PMBA. Strychnine, but not picrotoxinin, showed similar antagonism to PMBA. The potency of PMBA was independent of membrane potential between −100 and 0 mV.
When tested against EC50 concentrations of glycine, PMBA was almost equally potent on α1 (IC50, 406±41 nM: Hill coefficient, 1.5±0.2) and α2 (IC50, 539±56 nM; Hill coefficient, 1.4±0.2) homomers.
PMBA (1–10 μM) and strychnine (200 nM) reduced the potency of glycine and the amplitude of the maximal agonist response of α1 and α2 homomers. In 10 μM PMBA, two distinct classes of glycine response were observed on α2, only a single class of responses were observed on α1.
There are similarities in PMBA and strychnine antagonism, although these compounds are structurally distinct. The possibility that PMBA interacts at two binding sites which differ in α1 and α2 subunits is discussed. PMBA may provide a lead structure for novel antagonists with which to investigate structural differences in glycine receptor at α1 and α2 subunits.

British Journal of Pharmacology (1999) 126, 1230–1236; doi:10.1038/sj.bjp.0702402
Inverse agonist activity of pirenzepine at M2 muscarinic acetylcholine receptors
Authors: Daeffler Laurent , Schmidlin Fabien , Gies Jean‐Pierre , Landry Yves 
Published: January 2005

The intrinsic properties of muscarinic ligands were studied through their binding properties and their abilities to modulate the GTPase activity of G proteins coupled to muscarinic M2 receptors in pig atrial sarcolemma.
Competition binding experiments were performed with [3H]‐oxotremorine‐M to assess the affinity of receptors coupled to G proteins (R*), with [3H]‐N‐methylscopolamine ([3H]‐NMS) to estimate the affinities of coupled and uncoupled receptors (R*+R) and with [3H]‐NMS in the presence of GppNHp to assess the affinity of uncoupled receptors (R).
The ranking of Ki values for the agonist carbachol was R*<<R*+R<<R (0.95, 124 and 1017 nM). Ki values for atropine and AF‐DX 116 were similar for the three binding conditions (0.34, 0.42, 0.41 and 19, 22, 32 nM). The ranking of Ki values for pirenzepine was R*>R*+R>R (174, 155, 115 nM), suggesting inverse agonism.
The Vmax of the basal high affinity GTPase activity of pig atrial sarcolemma was increased by mastoparan and decreased by GPAnt‐2 indicating the relevance of this activity to G proteins coupled to receptors (R*). The KM value (0.26–0.33 μM) was not modified by mastoparan or GPAnt‐2.
Carbachol increased the Vmax of GTP hydrolysis (EC50 8.1±0.3 μM), whereas atropine and AF‐DX 116, up to 1 mM, did not modify it. Pirenzepine decreased the Vmax of GTP hydrolysis (EC50 77.5±10.3 μM). This effect was enhanced when KCl was substituted for NaCl (EC50 11.0±0.8 μM) and was antagonized by atropine and AF‐DX 116 (IC50 0.91±0.71 and 197±85 nM).
Pirenzepine is proposed as an inverse agonist and atropine and AF‐DX 116 as neutral antagonists at the muscarinic M2 receptor.

British Journal of Pharmacology (1999) 126, 1246–1252; doi:10.1038/sj.bjp.0702407
Activation of three types of voltage‐independent Ca2+ channel in A7r5 cells by endothelin‐1 as revealed by a novel Ca2+ channel blocker LOE 908
Authors: Iwamuro Yasushi , Miwa Soichi , Zhang Xiao‐Feng , Minowa Tetsuya , Enoki Taijiro , Okamoto Yasuo , Hasegawa Hiroshi , Furutani Hidekatsu , Okazawa Makoto , Ishikawa Masatsune , Hashimoto Nobuo , Masaki Tomoh 
Published: January 2005

We have shown that in addition to voltage‐operated Ca2+ channel (VOC), endothelin‐1 (ET‐1) activates two types of Ca2+‐permeable nonselective cation channel (NSCC) in A7r5 cells: its lower concentrations (1 nM; lower [ET‐1]) activate only an SK&F 96365‐resistant channel (NSCC‐1), whereas its higher concentrations (10 nM; higher [ET‐1]) activate an SK&F 96365‐sensitive channel (NSCC‐2) as well.
We now characterized the effects of a blocker ofCa2+ entry channel LOE 908 on NSCCs and store‐operatedCa2+ channel (SOCC) in A7r5 cells, and using twodrugs, clarified the involvement of these channels in the ET‐1‐inducedincrease in the intracellular free Ca2+ concentrations([Ca2+]i). Whole‐cell recordingsand [Ca2+]i monitoring withfluo‐3 were used.
LOE 908 up to 10 μM had no effect on increases in [Ca2+]i induced by thapsigargin or ionomycin, but SK&F 96365 abolished them.
In the cells clamped at −60 mV, both lower and higher [ET‐1] induced inward currents with linear iv relationships and the reversal potentials of −15.0 mV. Thapsigargin induced no currents.
In the presence of nifedipine, lower [ET‐1] induced a sustained increase in [Ca2+]i, whereas higher [ET‐1] induced a transient peak and a sustained increase. The sustained increases by lower and higher [ET‐1] were abolished by removal of extracellular Ca2+, and they were suppressed by LOE 908 to 0 and 35%, respectively, with the LOE 908‐resistant part being abolished by SK&F 96365.
These results show that LOE 908 is a blocker of NSCCs without effect on SOCC, and that the increase in [Ca2+]i at lower [ET‐1] results from Ca2+ entry through NSCC‐1 in addition to VOC, whereas the increase at higher [ET‐1] involves NSCC‐1, NSCC‐2 and SOCC in addition to VOC.

British Journal of Pharmacology (1999) 126, 1107–1114; doi:10.1038/sj.bjp.0702416
Electrophysiological studies on the postnatal development of the spinal antinociceptive effects of the delta opioid receptor agonist DPDPE in the rat
Authors: Rahman Wahida , Dickenson Anthony H 
Published: January 2005

The antinociceptive effects of the delta opioid receptor selective agonist, DPDPE [(D‐Pen2,D‐Pen5)‐enkephalin] was studied in rats aged postnatal day (P) 14, P21, P28 and P56.
Antinociceptive effects of DPDPE were measured as percentage inhibition of the C‐fibre evoked response and post‐discharge of dorsal horn neurones evoked by peripheral electrical stimulation. DPDPE was administered by topical application, akin to intrathecal injection.
DPDPE (0.1–100 μg) produced dose‐related inhibitions at all ages; these inhibitions were reversed by 5 μg of the opioid antagonist naloxone.
The dose‐response curves for C‐fibre evoked response and post‐discharge of the neurones were not different in rats aged P14 and P21. DPDPE was significantly more potent at P14 and P21 compared with its inhibitory effects on these responses at P28 and P56.
DPDPE produced minor inhibitions of the A‐fibre evoked response of the neurones at P14, P21, P28 and P56, suggesting that the inhibitory effects of DPDPE are mediated via presynaptic receptors on the terminals of C‐fibre afferents.
Since spinal delta opioid receptor density changes little over this period, the increased antinociceptive potency of DPDPE in the rat pups compared with the adult is likely to be due to post‐receptor events, or in developmental changes in the actions of other transmitter/receptor systems within the spinal cord.

British Journal of Pharmacology (1999) 126, 1115–1122; doi:10.1038/sj.bjp.0702418
Inhibition of GABA‐gated chloride channels by 12,14‐dichlorodehydroabietic acid in mammalian brain
Authors: Nicholson Russell A , Lees George , Zheng Jian , Verdon Bernard 
Published: January 2005

12,14‐dichlorodehydroabietic acid (12,14‐Cl2DHA) reduced GABA‐stimulated uptake of 36Cl− into mouse brain synaptoneurosomes suggesting inhibition of mammalian GABAA receptor function.
12,14‐Cl2DHA did not affect the binding of [3H]‐muscimol to brain membranes but displaced specifically bound [3H]‐EBOB. The inhibitory effect on [3H]‐EBOB binding was not reversible. 12,14‐Cl2DHA reduced the availability of [3H]‐EBOB binding sites (Bmax) without changing the KD of the radioligand for remaining sites. 12,14‐Cl2DHA did not affect the rate of association of [3H]‐EBOB with its chloride channel receptor, but increased the initial rate of [3H]‐EBOB dissociation.
12,14‐Cl2DHA enhanced the incidence of EPSCs when rapidly applied to cultured rat cortical neurones. Longer exposures produced block of IPSCs with marked increases in the frequency of EPSCs and min EPSCs. 12,14‐Cl2DHA also irreversibly suppressed chloride currents evoked by pulses of exogenous GABA in these cells.
Ultimately, 12,14‐Cl2DHA inhibited all synaptic traffic and action currents in current clamped cells indicating that, in contrast to picrotoxinin (which causes paroxysmal bursting), it is not fully selective for the GABAA receptor‐chloride channel complex.
The depolarizing block seen with 12,14‐Cl2DHA in amphotericin‐perforated preparations implicates loss of Ca2+ buffering in the polarity change and this may account for inhibition of spontaneous action potentials.
Our investigation demonstrates that 12,14‐Cl2DHA blocks GABA‐dependent chloride entry in mammalian brain and operates as a non‐competitive insurmountable GABAA antagonist. The mechanism likely involves either irreversible binding of 12,14‐Cl2DHA to the trioxabicyclooctane recognition site or a site that is allosterically coupled to it. We cannot exclude, however, the possibility that 12,14‐Cl2DHA causes localized proteolysis or more extensive conformational change within a critical subunit of the chloride channel.

British Journal of Pharmacology (1999) 126, 1123–1132; doi:10.1038/sj.bjp.0702419
Limited anti‐inflammatory efficacy of cyclo‐oxygenase‐2 inhibition in carrageenan‐airpouch inflammation
Authors: Wallace John L , Chapman Kevin , McKnight Webb 
Published: January 2005

Cyclo‐oxygenase‐2 (COX‐2) is expressed at sites of inflammation and is believed to be the major source of inflammation‐associated prostaglandin synthesis. Selective inhibition of COX‐2 has been suggested to produce anti‐inflammatory effects with reduced toxicity in the gastrointestinal tract. We examined the extent to which suppression of COX‐2 led to inhibition of various components of inflammation in the carrageenan‐airpouch model in the rat.
Indomethacin (0.3 mg kg−1), nimesulide (3 mg kg−1) and the selective COX‐2 inhibitor, SC‐58125 (0.3 mg kg−1), significantly suppressed the production of prostaglandin E2 at the site of inflammation. At higher doses, indomethacin (1 mg kg−1) and nimesulide (30 mg kg−1), but not SC‐58125 (up to 10 mg kg−1), significantly inhibited COX‐1 activity (as measured by whole blood thromboxane synthesis).
All three test drugs significantly reduced the volume of exudate in the airpouch, but only at doses greater than those required for substantial (>90%) suppression of COX‐2 activity. Similarly, reduction of leukocyte infiltration was only observed with the doses of indomethacin and nimesulide that caused significant suppression of COX‐1 activity.
SC‐58125 did not significantly affect leukocyte infiltration into the airpouch at any dose tested (up to 10 mg kg−1). A second selective COX‐2 inhibitor, Dup‐697, was also found to suppress exudate PGE2 levels without significant effects on leukocyte infiltration.
These results indicate that selective inhibition of COX‐2 results in profound suppression of PGE2 synthesis in the carrageenan‐airpouch, but does not affect leukocyte infiltration. Exudate volume was only reduced with the highly selective COX‐2 inhibitor when a dose far above that necessary for suppression of COX‐2 activity was used. Inhibition of leukocyte infiltration was observed with indomethacin and nimesulide, but only at doses that inhibited both COX‐1 and COX‐2.

British Journal of Pharmacology (1999) 126, 1200–1204; doi:10.1038/sj.bjp.0702420
Protective effect of cyclosporin A and FK506 from nitric oxide‐dependent apoptosis in activated macrophages
Authors: Hortelano Sonsoles , López‐Collazo Eduardo , Boscá Lisardo 
Published: January 2005

Activation of macrophages with lipopolysaccharide (LPS) and low doses of interferon‐γ (IFN‐γ) induced apoptotic death through a nitric oxide‐dependent pathway.
Treatment of cells with the immunosuppressors cyclosporin A (CsA) or FK506 inhibited the activation‐dependent apoptosis.
These drugs decreased the up‐regulation of p53 and Bax characteristic of activated macrophages. Moreover, incubation of activated macrophages with CsA and FK506 contributed to maintain higher levels of Bcl‐2 than in LPS/IFN‐γ treated cells.
The inhibition of apoptosis exerted by CsA and FK506 in macrophages was also observed when cell death was induced by treatment with chemical nitric oxide donors.
Incubation of macrophages with LPS/IFN‐γ barely affected caspase‐1 but promoted an important activation of caspase‐3. Both CsA and FK506 inhibited pathways leading to caspase‐3 activation. Moreover, the cleavage of poly(ADP‐ribose) polymerase, a well established caspase substrate, was reduced by these immunosuppressive drugs.
CsA and FK506 reduced the release of cytochrome c to the cytosol and the activation of caspase‐3 in cells treated with nitric oxide donors.
These results indicate that CsA and FK506 protect macrophages from nitric oxide‐dependent apoptosis and suggest a contribution of the macrophage to innate immunity under conditions of immunosuppression of the host.

British Journal of Pharmacology (1999) 126, 1139–1146; doi:10.1038/sj.bjp.0702422
Interleukin‐1α and tumour necrosis factor‐α modulate airway smooth muscle DNA synthesis by induction of cyclo‐oxygenase‐2: inhibition by dexamethasone and fluticasone propionate
Authors: Vlahos Ross , Stewart Alastair G 
Published: January 2005

Previous studies have established that glucocorticoids inhibit airway smooth muscle DNA synthesis. The effects of a combination of the pro‐inflammatory cytokines, interleukin‐1α (IL‐1α) and tumour necrosis factor‐α (TNF‐α) on the inhibition of DNA synthesis by glucocorticoids in human cultured airway smooth muscle have now been investigated, since these cytokines are chronically expressed in asthmatic airways.
Thrombin (0.3 u ml−1) and basic fibroblast growth factor (bFGF, 300 pM) stimulated increases in DNA synthesis which were concentration‐dependently inhibited by dexamethasone (1–1000 nM).
The cytokine mixture, comprising IL‐1α (0.01 and 0.1 pM) and TNF‐α (3 and 30 pM), directly evoked increases in DNA synthesis which were attenuated by dexamethasone. However, the cytokine mixture prevented responses to bFGF or thrombin.
Paradoxically, in the presence of the cytokine mixture and bFGF, dexamethasone (1–1000 nM) concentration‐dependently increased DNA synthesis. Furthermore, neither dexamethasone (100 nM) nor fluticasone propionate (1 nM) inhibited DNA synthesized in response to bFGF/cytokine mixture combination and dexamethasone was similarly inactive against the thrombin/cytokine mixture.
The levels of prostaglandin E2 (PGE2), an established inhibitor of airway smooth muscle DNA synthesis, remained below the limits of assay detection (0.05 nM) under basal conditions or following stimulation with either thrombin or bFGF. In contrast, the cytokine mixture alone, and in the presence of thrombin or bFGF, induced biologically active levels of PGE2. Dexamethasone (100 nM), the non‐selective cyclo‐oxygenase (COX) inhibitor indomethacin (3 μM) or the selective COX‐2 inhibitor L‐745,337 (0.3 μM) completely inhibited synthesis of PGE2.
Neither indomethacin (3 μM) nor L‐745,337 (0.3 μM) influenced thrombin‐ or bFGF‐induced DNA synthesis. However, each COX inhibitor enhanced DNA synthesis in cytokine‐treated cells.
In unstimulated airway smooth muscle cells, COX‐1, but not COX‐2 protein was detectable by Western blotting. The induction of COX‐2 protein by the cytokine mixture was attenuated by dexamethasone (100 nM), whereas the level of COX‐1 protein was unaffected by either the cytokines or by dexamethasone.
Cytokine‐induced, COX‐2‐dependent eicosanoid production inhibits DNA synthesis. The paradoxical increase in DNA synthesis observed in glucocorticoid treated airway smooth muscle stimulated by cytokine/bFGF combinations may be explained by the ability of glucocorticoids to repress COX‐2 induction and prevent cytokine‐induction of the DNA synthesis inhibitor, PGE2.

British Journal of Pharmacology (1999) 126, 1315–1324; doi:10.1038/sj.bjp.0702424
Effects of intravenous administration of prostacyclin on regional blood circulation in awake rats
Authors: Raczka Ewa , Quintana Antonio 
Published: January 2005

The effects of intravenous infusion of prostacyclin (PGI2, 0.1, 0.2, 0.3 and 1.0 μg kg−1 min−1 lasting 5 min) on regional blood flow and regional vascular resistance have been studied in awake rats using the radioactive microsphere method.
The control values of blood flow to the heart, kidney, small intestine, hind limb muscle, pericranial skin and brain as well as the corresponding vascular resistance were not modified by an i.v. infusion (0.1 ml min−1) of Tris‐buffer (the vehicle of PGI2).
The i.v. infusion of PGI2 produced graded dose‐dependent decreases of MAP (r=0.87, P<0.001; ED20=0.73 [0.13–2.55] μg kg−1 min−1) as well as decreases of vascular resistance in the heart (r=0.83, P<0.001; ED30=0.17 [0.09–0.31] μg kg−1 min−1), pericranial skin (r=0.88, P<0.001; ED30=0.28 [0.18–0.43] μg kg−1 min−1) and small intestine (r=0.74, P<0.001; ED30=0.21 [0.11–0.39] μg kg−1 min−1), which led to dose‐related increases of blood flow to these territories.
On the contrary, PGI2 increased vascular resistance in skeletal muscle (r=0.73, P<0.001; ED30=0.20 [0.10–0.39] μg kg−1 min−1) with corresponding reductions in blood flow. The low doses reduced renal blood flow but there were no significant changes during the high ones. Cerebral vessels did not dilate during any infusion of PGI2 and cerebral blood flow decreased as MAP fell (r=0.56, P<0.01).
We conclude that, in awake rats, the coronary vessels are extremely sensitive to the vasodilating effect of PGI2 and that the mesenteric vessels and those of the pericranial skin are very responsive too. Moreover, autoregulation is inefficient to maintain cerebral blood flow during infusion of PGI2.

British Journal of Pharmacology (1999) 126, 1325–1332; doi:10.1038/sj.bjp.0702426
Effects of propafenone on K currents in human atrial myocytes
Authors: Seki Akiko , Hagiwara Nobuhisa , Kasanuki Hiroshi 
Published: January 2005

The class Ic anti‐arrhythmic agent, flecainide is known to inhibit the transient outward K current (Ito) selectively in human atrium. We studied the effects of propafenone, another class Ic anti‐arrhythmic agent, on K currents in human atrial myocytes using a whole‐cell voltage‐clamp method.
Propafenone inhibited both Ito and the sustained or ultra‐rapid delayed rectifier K current (Isus or Ikur) evoked by depolarization pulses. The concentration for half‐maximal inhibition (IC50) was 4.9 μM for Ito and 8.6 μM for Isus. Propafenone blocked Ito and Isus in a voltage‐ and use‐independent fashion and accelerated the inactivation time constant of Ito [from 28.3 to 6.7 ms at 10 μM propafenone].
The steady‐state inactivation curve for Ito was unaffected by propafenone. Propafenone did not affect the initial current at depolarizing potentials, but it did produce a block that increased as a function of time after depolarization (time constant of 3.4 ms). This suggests that propafenone preferentially blocked Ito in the open state.
Propafenone had no significant effect on the rate at which Ito recovered from inactivation at −80 mV suggesting that propafenone dissociates rapidly from the channel.
The steady‐state activation curve for Isus was not affected by propafenone. Propafenone slowed the time course of the onset of the Isus tail current. This suggests that propafenone blocked Isus in the open state.
The present results suggest that, unlike flecainide, propafenone blocks both Ito and Isus in human atrial myocytes in the open state at clinically relevant concentrations.

British Journal of Pharmacology (1999) 126, 1153–1162; doi:10.1038/sj.bjp.0702428
The vasoconstrictor effect of 8‐epi prostaglandin F2α in the hypoxic rat heart
Authors: Kromer Brendan M , Tippins John R 
Published: January 2005

8‐epi prostaglandin (PG) F2α, a vasoconstrictor isoprostane, is synthesized under conditions of oxidative stress. This study was undertaken to investigate the vasoconstrictor effect of 8‐epi PGF2α in the coronary circulation before and after a period of oxidative stress.
The effects of the isoprostane 8‐epi PGF2α and the thromboxane mimetic U46619 were compared in the isolated rat heart perfused in the Langendorff mode at a constant pressure of 80 mmHg.
In normal hearts U46619 caused a dose‐related reduction in coronary flow (ED50 4.7±2.2 nmol). In contrast, 8‐epi PGF2α had no effect.
After reducing perfusion pressure to 20 mmHg for 30 min and reperfusing at 80 mmHg, the dose‐response curve to U46619 was unaffected. In contrast, 8‐epi PGF2α caused a dose‐dependent drop in coronary flow (ED50 52.6±12.7 nmol), producing a similar maximal reduction to U46619.
Similarly, after perfusion with xanthine and xanthine oxidase for either 15 or 30 min there was little change in the response to U46619 in comparison to control hearts. In contrast, 8‐epi PGF2α caused a reduction in coronary flow similar to that produced by U46619, the magnitude of the response being related to the length of xanthine/xanthine oxidase perfusion.
Responses to both U46619 and 8‐epi PGF2α after xanthine/xanthine oxidase perfusion were blocked by the selective thromboxane receptor antagonist SQ29548 10−7 M.
These results show that oxidative stress in the isolated perfused rat heart reveals a potent vasoconstrictor effect of the isoprostane 8‐epi PGF2α by an action on the thromboxane receptor.
The data also suggest that, since 8‐epi PGF2α is a partial agonist at the thromboxane receptor, thromboxane receptor reserve is increased by oxidative stress.

British Journal of Pharmacology (1999) 126, 1171–1174; doi:10.1038/sj.bjp.0702433