Abstract:
:In electrophysiological measurements the beta-carboline ethyl 6-benzyloxy-beta-carboline-3-carboxylate (ZK 91085) acts as a positive allosteric modulator on rat recombinant alpha1beta2gamma2 GABA(A) receptors and binds with high affinity (IC50-1.5 nM) to the [3H]-flunitrazepam site. Flumazenil was able to partially counteract the current modulation. These observations indicate an action of ZK 91085 at the benzodiazepine binding site. At the dual subunit combination alpha1beta2, which lacks the gamma subunit required for benzodiazepine modulation, we still observed a potentiation of GABA currents. Thus ZK 91085 acts via an additional site on the channel. At the subunit combination alpha1beta1, ZK 91085 potentiation is strongly reduced as compared to alpha1beta2. In binding studies, ZK 91085 was able to decrease [35S]-TBPS binding in alpha1beta2gamma2 and alpha1beta2 but not in alpha1beta1. This selectivity of ZK 91085 for receptors containing the beta2 isoform over those containing the beta1 isoform is reminiscent of the action of loreclezole. To identify amino acid residues important for the second type of modulation, we functionally compared wild type alpha1beta2 and mutant receptors for stimulation by ZK 91085. The mutation beta2N265S, that abolishes loreclezole effects, also abolishes ZK 91085 stimulation. The mutation beta2Y62L increased stimulation by ZK 91085 3-4 fold, locating an influencing entity of the second type of action of ZK 91085 at an alpha/beta subunit interface. Structural intermediates of ZK 91085 and the beta-carboline abecarnil, the latter of which only slightly potentiated GABA currents in alpha1/beta2, were analysed to determine structural requirements for modulation. ZK 91085 thus allosterically stimulates the GABA(A) receptor through two sites of action: the benzodiazepine site and the loreclezole site in contrast to classical beta-carbolines, that confer negative allosteric modulation through the benzodiazepine site.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Thomet U,Baur R,Scholze P,Sieghart W,Sigel Edoi
10.1038/sj.bjp.0702639subject
Has Abstractpub_date
1999-07-01 00:00:00pages
1231-9issue
5eissn
0007-1188issn
1476-5381journal_volume
127pub_type
杂志文章abstract:BACKGROUND AND PURPOSE:N-docosahexaenoylethanolamine (DHEA) is the ethanolamine conjugate of the long-chain polyunsaturated n-3 fatty acid docosahexaenoic (DHA; 22: 6n-3). Its concentration in animal tissues and human plasma increases when diets rich in fish or krill oil are consumed. DHEA displays anti-inflammatory pr...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.12747
更新日期:2015-01-01 00:00:00
abstract::1. We previously demonstrated that cyclopiazonic acid (CPA), an inhibitor of Ca(2+)-ATPase in the sarcoplasmic reticulum, induced rhythmic relaxations of active tension in the endothelium-denuded small arteries of the mesentery and the ear of the rabbit, but that this agent failed to induce rhythmic responses in the e...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15392.x
更新日期:1996-05-01 00:00:00
abstract::1. Propranolol, a beta-adrenoceptor blocking drug with local anaesthetic and a direct myocardial depressant action, and MJ 1999, a beta-adrenoceptor blocking drug which has no local anaesthetic or intrinsic sympathomimetic action, were compared for beta-adrenoceptor blocking activity in man.2. Propranolol was 2.67 tim...
journal_title:British journal of pharmacology
pub_type: 临床试验,杂志文章
doi:10.1111/j.1476-5381.1970.tb10596.x
更新日期:1970-05-01 00:00:00
abstract::Cellular electrophysiological effects of membrane lipid peroxidation by t-butyl hydroperoxide (TBH) were studied in the rabbit sinoatrial (SA) node. Superfusion for 1-5 min with 300 microM TBH caused an initial increase and subsequent decrease in the spontaneous firing frequency of the SA node. Voltage clamp experimen...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb14598.x
更新日期:1989-11-01 00:00:00
abstract::1. The calcium sensitivity of force production of cardiac muscle fibres is altered by certain drugs. The sites of action of three such compounds (pimobendan, sulmazole, isomazole) within the myofibril have been investigated. Calmodulin antagonists, perhexilene and bepridil, which have been shown to alter the calcium d...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1990.tb14092.x
更新日期:1990-08-01 00:00:00
abstract::1 Cellulose sulphate, like heparin, prolonged the clotting time in partial thromboplastin time (PTT) assays, inhibited the amidolytic activity of thrombin, was without effect on amidolysis catalysed by activated coagulation factor X(Xa), and potentiated the inhibition of both thrombin and Xa by antithrombin III (AT). ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1980.tb10856.x
更新日期:1980-04-01 00:00:00
abstract::1. The effect of intradermally injected endotoxin on skin blood flow was investigated in anaesthetized male Wistar rats in vivo. 2. Local skin blood flow changes were measured hourly for 6 h in the shaved dorsal skin with a laser-Doppler flow probe and compared to changes in control sites which had been injected with ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14441.x
更新日期:1992-08-01 00:00:00
abstract::1. Acute moderate hypoxia modifies the catalytic activity and expression of certain isoenzymes of hepatic cytochrome P450 (P450). The aim of this study was to document whether hypoxia affects hepatic P450 directly or through the release of serum mediators. 2. Rabbits were subjected to a FiO(2) of 8% for 48 h, sacrific...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0704933
更新日期:2002-11-01 00:00:00
abstract::1. Bepridil (BPD) is a pharmacological compound able to bind to the Ca2+ sensor protein troponin C (TnC), which triggers skeletal muscle contraction upon Ca2+-binding. BPD can thereby modulate the Ca2+-affinity of this protein. 2. The Ca2+-sensitizing action of bepridil was investigated on slow and fast isoforms of Tn...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702820
更新日期:1999-10-01 00:00:00
abstract::1 The activity pattern of analogues of the enkephalins was determined in four parallel assays, the inhibition of the electrically evoked contraction of the guinea-pig ileum and mouse vas deferens at 36 degrees C and the inhibition of [(3)H]-naltrexone and [(3)H]-leucine-enkephalin binding at 0 to 4 degrees C in homoge...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1980.tb10422.x
更新日期:1980-02-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Xaliproden (SR57746A) is a 5-HT(1A) receptor agonist and neurotrophic agent that reduces oxaliplatin-mediated neuropathy in clinical trials. The present study investigated its profile on in vitro transduction, neurochemical responses and acute nociceptive pain tests in rats. EXPERIMENTAL APPROAC...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2009.00249.x
更新日期:2009-09-01 00:00:00
abstract::1. Optimal dipeptide and peptidomimetic drug transport across the intestinal mucosal surface is dependent upon the co-operative functional activity of the di/tripeptide transporter hPepT1 and the Na(+)/H(+) exchanger NHE3. The ability of the anti-absorptive enteric neuropeptide VIP (vasoactive intestinal peptide) to m...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0705049
更新日期:2003-02-01 00:00:00
abstract::1. Alprenolol, a beta-adrenoceptor blocking drug reported to have the same potency as propranolol in vitro and in vivo, was found to be four times more active than procaine as a local anaesthetic on frog sciatic nerve.2. At doses of 0.125 mg/kg and above alprenolol protected anaesthetized guinea-pigs against ouabain-i...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1970.tb09884.x
更新日期:1970-04-01 00:00:00
abstract::1. Chronic treatment with a combined ETA/ETB endothelin receptor antagonist has been shown to reduce blood pressure in experimental rat models of hypertension in which endothelin-1 gene overexpression occurs in the walls of blood vessels, particularly small, resistance-sized arteries, but not in those genetic or exper...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701224
更新日期:1997-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Positive modulators of small conductance Ca(2+)-activated K(+) channels (SK1, SK2, and SK3) exert hyperpolarizing effects that influence the activity of excitable and non-excitable cells. The prototype compound 1-EBIO or the more potent compound NS309, do not distinguish between the SK subtypes a...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0707281
更新日期:2007-07-01 00:00:00
abstract::1. Cold storage (2 degrees C) treatment progressively reduced noradrenaline uptake by the taenia caecum of the guinea-pig. After 15 days of cold treatment, [(3)H]-noradrenaline uptake by tissue was reduced to about 10% of control. On the other hand, prolonged cold storage failed to decrease [(3)H]-adenosine uptake by ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1973.tb08539.x
更新日期:1973-12-01 00:00:00
abstract::The aim of the present study was to investigate the contribution of bradykinin (BK) B(1) and B(2) receptors in a model of type III hypersensitivity, the reverse passive Arthus reaction (RPA), in wild-type mice and transgenic B(2) knockout littermates. BK (10 microg mouse(-1)) or bovine serum albumin (0.5 mg mouse(-1))...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703225
更新日期:2000-04-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Kyotorphin (KTP; L-Tyr-L-Arg), an endogenous neuropeptide, is potently analgesic when delivered directly to the central nervous system. Its weak analgesic effects after systemic administration have been explained by inability to cross the blood-brain barrier (BBB) and detract from the possible cl...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01290.x
更新日期:2011-07-01 00:00:00
abstract::1. This study was undertaken to evaluate in vivo the influence of amiodarone on the effects of triiodothyronine (T3) in brown adipose tissue (BAT) which are independent of thyroid hormone synthesis and of the conversion of thyroxine (T4) to T3. Thyroidectomized rats were given a replacement dose of T3 (0.5 mg kg(-1) p...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702456
更新日期:1999-03-01 00:00:00
abstract::1 The effects of raising or lowering [Ca(2+)](o) or [Mg(2+)](o) on potential changes evoked by 5-hydroxytryptamine (5-HT) and by the nicotinic agonist, 1,1-dimethyl-4-phenyl piperazinium (DMPP) have been investigated.2 Changes in membrane potential were measured at the ganglion or in postganglionic axons by the sucros...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1981.tb16813.x
更新日期:1981-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Pancreatic cancer is a solid tumour that is often fatal. Hence, there is an urgent need to identify new drug targets for this disease. Highly proliferating cancer cells have an increased demand for nutrients and, therefore, need to up-regulate selective amino acid transporters. Here, we investiga...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13616
更新日期:2016-12-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inhaled corticosteroids (ICS) are the cornerstone of asthma pharmacotherapy and, acting via the glucocorticoid receptor (GR), reduce inflammatory gene expression. While this is often attributed to a direct inhibitory effect of the GR on inflammatory gene transcription, corticosteroids also induce...
journal_title:British journal of pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1476-5381.2011.01620.x
更新日期:2012-03-01 00:00:00
abstract::Strips of human pulmonary arteries from patients undergoing surgery for lung tumour were incubated with [3H]-noradrenaline. Subsequently, they were superfused with physiological salt solution containing cocaine and corticosterone. Tritium overflow from the strips was stimulated by transmural electrical impulses (2 Hz)...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1985.tb11094.x
更新日期:1985-08-01 00:00:00
abstract::1 The effect of intrarenal histamine, dimaprit (H2-agonist) and 2-(2-pyridyl) ethylamine (H1-agonist) on renin release was examined in anaesthetized dogs. 2 In dogs with intact kidneys, histamine and dimaprit administration resulted in renal vasodilatation, a two fold increase in urinary sodium excretion, and no chang...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1983.tb10495.x
更新日期:1983-05-01 00:00:00
abstract::Midbrain dopaminergic (DA) neurones sustain important physiological functions such as control of motricity, signalling of the error in prediction of rewards and modulation of emotions and cognition. Moreover, their degeneration leads to Parkinson's disease and they may be dysfunctional in other pathological states, su...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/sj.bjp.0706328
更新日期:2005-09-01 00:00:00
abstract::The binding characteristics of the relaxin receptor in rat atria, uterus and cortex were studied using a [33P]-labelled human gene 2 relaxin (B33) and quantitative receptor autoradiography. The binding kinetics of [33P]-human gene 2 relaxin (B33) were investigated in slide-mounted rat atrial sections. The binding achi...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702517
更新日期:1999-05-01 00:00:00
abstract::1 Effects of dopamine and noradrenaline were compared in helically-cut strips of canine cerebral arteries. 2 Dopamine caused a greater maximal contraction than noradrenaline, although the ED50 for noradrenaline was appreciably less. The contraction induced by these amines was reversed to a relaxation by treatment with...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1976.tb07700.x
更新日期:1976-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:This study investigated the role of central sympathetic activity and related mitogen-activated protein kinase (MAPK) signalling in the cardiovascular effects of ethanol in a model of acute renal failure (ARF). EXPERIMENTAL APPROACH:The effects of pharmacological interventions that inhibit periph...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2009.00444.x
更新日期:2009-11-01 00:00:00
abstract::1. In pithed rats, preganglionic vagal nerve stimulation (at 5 Hz) elicited a bradycardia. This bradycardia was potentiated by the angiotensin converting enzyme inhibitor, captopril (1 mg kg-1, i.v.) by about 40%. Subsequent angiotensin II infusion (0.03 micrograms kg-1 min-1) reversed this effect. A similar facilitat...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13807.x
更新日期:1993-09-01 00:00:00
abstract::1. To elucidate whether K+ channels play a role in the action of epithelium-dependent bronchodilatation, we studied responses in human bronchial strips in the presence of indomethacin and NG-nitro-L-arginine methylester under isometric conditions, in vitro. 2. Mechanical removal of the epithelium increased the contrac...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701183
更新日期:1997-06-01 00:00:00