Abstract:
:1. Lowering of the extracellular Mg(2+)-concentration induces various patterns of epileptiform activity in combined rat entorhinal cortex-hippocampal brain slices. After a prolonged period of exposure to Mg(2+)-free medium seizure-like events in the entorhinal cortex change to a state of late recurrent discharges which cannot be blocked by clinically available antiepileptic drugs. This late epileptiform activity thus represents a useful model to test the effects of new anticonvulsant substances. 2. A mechanism possibly underlying the development of sustained seizure-like activity is the loss of synaptically released gamma-aminobutyric acid (GABA). Drugs which increase the amount of GABA available in presynaptic endings might thus be useful in the treatment of these therapeutically complicated forms of epilepsy. 3. Therefore, we studied the effects of various substances increasing GABA-mediated inhibition on early and late forms of epileptiform activity. GABA and the GABAA receptor agonist muscimol blocked both the pharmacosensitive discharges in the hippocampus and entorhinal cortex as well as the late recurrent discharges in the medial entorhinal cortex. The GABAB receptor agonist baclofen blocked the recurrent short discharges very potently, but did not consistently block seizure-like events and late recurrent discharges in the entorhinal cortex. 4. GABA uptake blockers showed a differential potency to block the various discharge patterns. Whereas nipecotic acid and beta-alanine suppressed all forms of epileptiform activity albeit at high concentrations (1-5 mM), tiagabine was much more potent in blocking the hippocampal recurrent short discharges and the seizure-like events in the medial entorhinal cortex, but could not block the late recurrent discharges. 5. Our data support the idea that prolonged neuronal overactivity might result in a loss of synaptically available GABA. Selective block of uptake into glia cells or substitution of the transmitter may therefore be an efficient strategy for the treatment of severe prolonged epileptic discharges whereas block of neuronal GABA uptake fails to counteract synchronized discharges in this situation.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Pfeiffer M,Draguhn A,Meierkord H,Heinemann Udoi
10.1111/j.1476-5381.1996.tb15710.xsubject
Has Abstractpub_date
1996-10-01 00:00:00pages
569-77issue
3eissn
0007-1188issn
1476-5381journal_volume
119pub_type
杂志文章abstract::1. PD 81,723 has been shown to enhance binding of adenosine to A1 receptors by stabilizing G protein-receptor coupling ('allosteric enhancement'). Evidence has been provided that in the perfused hearts and isolated atria PD 81,723 causes a sensitization to adenosine via this mechanism. 2. We have studied the effect of...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701254
更新日期:1997-07-01 00:00:00
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journal_title:British journal of pharmacology
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doi:10.1111/j.1476-5381.1985.tb10563.x
更新日期:1985-07-01 00:00:00
abstract::In recent years, late-stage clinical drug development that primarily focuses on urogenital targets has centered around four areas of medical need (both unmet need and aiming to improve on existing therapies). These include male sexual dysfunction (MSD), female sexual dysfunction (FSD), prostatic pathology (neoplastic,...
journal_title:British journal of pharmacology
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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
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abstract::The aim of this study was to characterize the angiotensin II receptors in isolated uterine arteries from non pregnant and pregnant rats, since it has been reported from binding studies that ovine uterine arteries contain AT2 receptors. Uterine arterial segments were obtained from virgin, non-pregnant and late pregnant...
journal_title:British journal of pharmacology
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doi:10.1038/sj.bjp.0702210
更新日期:1998-12-01 00:00:00
abstract::The smooth muscle relaxant responses to the mixed beta(3)-, putative beta(4)-adrenoceptor agonist, (-)-CGP 12177 in rat colon are partially resistant to blockade by the beta(3)-adrenoceptor antagonist SR59230A suggesting involvement of beta(3)- and putative beta(4)-adrenoceptors. We now investigated the function of th...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703365
更新日期:2000-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Up-regulation of thioredoxin interacting protein (TXNIP), an endogenous inhibitor of thioredoxin (Trx), compromises cellular antioxidant and anti-apoptotic defences and stimulates pro-inflammatory cytokines expression, implying a role for TXNIP in apoptosis. Here we have examined the causal role ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01336.x
更新日期:2011-09-01 00:00:00
abstract::1. The present study shows the effects of imipramine in a single dose (10 mg kg(-1), p.o.) or following repeated (14 days, twice a day) treatment on the level of mRNA coding for D2 dopamine receptors in the rat caudate putamen (CP). Repeated administration of imipramine resulted in the increase of the level of mRNA co...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701681
更新日期:1998-03-01 00:00:00
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更新日期:2008-07-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
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更新日期:2001-08-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702434
更新日期:1999-03-01 00:00:00
abstract::1. In order to determine whether activation of adenosine triphosphate (ATP)-sensitive K+ channels exclusively explains the hypoxia- and ischaemia-induced action potential shortening, effects of tolbutamide and glibenclamide on changes in action potential duration (APD) during hypoxia, metabolic blockade or experimenta...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12294.x
更新日期:1991-05-01 00:00:00
abstract::RSD 921 is a novel, structurally unique, class I Na+ channel blocking drug under development as a local anaesthetic agent and possibly for the treatment of cardiac arrhythmias. The effects of RSD 921 on wild-type heart, skeletal muscle, neuronal and non-inactivating IFMQ3 mutant neuronal Na+ channels expressed in Xeno...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702488
更新日期:1999-05-01 00:00:00
abstract::1. Carrier mediated uptake (uptake-1) transport of norepinephrine (NE) plays a key role in the regulation of sympathetic neurotransmission. Recent investigations indicate that nitric oxide (NO) may modulate uptake-1 activity, possibly in a cyclic GMP independent manner. 2. Carrier mediated transport of [(3)H-NE] and [...
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pub_type: 杂志文章
doi:10.1038/sj.bjp.0703416
更新日期:2000-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:(R,S)-ketamine produces rapid and significant antidepressant effects in approximately 65% of patients suffering from treatment-resistant bipolar depression (BD). The genetic, pharmacological and biochemical differences between ketamine responders and non-responders have not been identified. The p...
journal_title:British journal of pharmacology
pub_type: 杂志文章,随机对照试验
doi:10.1111/bph.12494
更新日期:2014-04-01 00:00:00
abstract::Alzheimer's disease (AD) is the most common age related neurodegenerative disease. Currently, there are no disease modifying drugs, existing therapies only offer short-term symptomatic relief. Two of the pathognomonic indicators of AD are the presence of extracellular protein aggregates consisting primarily of the Aβ ...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
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更新日期:2011-05-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/bjp.2008.145
更新日期:2008-06-01 00:00:00
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pub_type: 杂志文章
doi:10.1038/sj.bjp.0703834
更新日期:2001-01-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
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更新日期:2000-10-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14482.x
更新日期:1992-09-01 00:00:00
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更新日期:2016-02-01 00:00:00
abstract::In perfused rabbit adrenal glands, colchicine (500 muM) inhibited the catecholamine secretion evoked by acetylcholine (20 mug/ml) but not that evoked by excess potassium (60 mM). Since both stimuli are believed to release catecholamines ultimately by the same secretory process, exocytosis, it is concluded that these i...
journal_title:British journal of pharmacology
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更新日期:1972-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The effect of age on the distribution of morphine and morphine-3-glucuronide (M3G) across the blood-brain barrier (BBB) was studied in a sheep model utilizing intracerebral microdialysis. The effect of neonatal asphyxia on brain drug distribution was also studied. EXPERIMENTAL APPROACH:Microdial...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2009.00242.x
更新日期:2009-07-01 00:00:00
abstract::1. It has been reported that activation of beta-adrenoceptors may be responsible for the hyperaemic response of the hepatic artery to portal venous blood flow reduction. 2. The effect of beta-adrenoceptor blockade on the hepatic arterial response to portal vein occlusion was investigated in 6 anaesthetized dogs. A sid...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb11825.x
更新日期:1989-02-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/bjp.2008.350
更新日期:2008-11-01 00:00:00
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更新日期:2019-06-01 00:00:00
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journal_title:British journal of pharmacology
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doi:10.1038/bjp.2008.71
更新日期:2008-05-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
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更新日期:2017-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Protease-activated receptor 1 (PAR1) has been demonstrated to be involved in the pathogenesis of viral diseases. However, its role remains controversial. The goal of our study was to investigate the contribution of PAR1 to respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) infecti...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.14084
更新日期:2018-01-01 00:00:00
abstract::1. The role of nitic oxide (NO) derived from L-arginine in the regional vasodilator effects of endothelin-1 has been investigated in anaesthetized, spontaneously hypertensive (SH) rats in which autonomic reflexes were abolished by ganglion blockade. The experimental design incorporated animals infused with phenylephri...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb09049.x
更新日期:1992-03-01 00:00:00