76
|
Song Y, Schlesinger F, Petri S, Dengler R, Krampfl K. Open-channel-block induced by the neurotransmitter glycine in homomeric alpha1-GlyR and heteromeric alpha1/beta1- GlyR. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
77
|
Borngräber M, Schlesinger F, Petri S, Dengler R, Krampfl K. ZK200775, ZK187638, ZK238519 and ZK166350: comparison of different potent antagonists of AMPA-type glutamate receptor channels and their potential role for neuroprotection. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
78
|
Mohammadi B, Kollewe K, Krampfl K, Samii A, Dengler R, Münte T. Changes in cortical and subcortical motor activity in early ALS studied with fMRI. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
79
|
Haeseler G, Karst M, Foadi N, Gudehus S, Roeder A, Hecker H, Dengler R, Leuwer M. High-affinity blockade of voltage-operated skeletal muscle and neuronal sodium channels by halogenated propofol analogues. Br J Pharmacol 2008; 155:265-75. [PMID: 18574460 DOI: 10.1038/bjp.2008.255] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Voltage-operated sodium channels constitute major target sites for local anaesthetic-like action. The clinical use of local anaesthetics is still limited by severe side effects, in particular, arrhythmias and convulsions. These side effects render the search for new local anaesthetics a matter of high interest. EXPERIMENTAL APPROACH We have investigated the effects of three halogenated structural analogues of propofol on voltage-operated human skeletal muscle sodium channels (Na(V)1.4) and the effect of one compound (4-chloropropofol) on neuronal sodium channels (Na(V)1.2) heterologously expressed in human embryonic kidney cell line 293. KEY RESULTS 4-Iodo-, 4-bromo- and 4-chloropropofol reversibly suppressed depolarization-induced whole-cell sodium inward currents with high potency. The IC(50) for block of resting channels at -150 mV was 2.3, 3.9 and 11.3 microM in Na(V)1.4, respectively, and 29.2 microM for 4-chloropropofol in Na(V)1.2. Membrane depolarization inducing inactivation strongly increased the blocking potency of all compounds. Estimated affinities for the fast-inactivated channel state were 81 nM, 312 nM and 227 nM for 4-iodopropofol, 4-bromopropofol and 4-chloropropofol in Na(V)1.4, and 450 nM for 4-chloropropofol in Na(V)1.2. Recovery from fast inactivation was prolonged in the presence of drug leading to an accumulation of block during repetitive stimulation at high frequencies (100 Hz). CONCLUSIONS AND IMPLICATIONS Halogenated propofol analogues constitute a novel class of sodium channel-blocking drugs possessing almost 100-fold higher potency compared with the local anaesthetic and anti-arrhythmic drug lidocaine. Preferential drug binding to inactivated channel states suggests that halogenated propofol analogues might be especially effective in suppressing ectopic discharges in a variety of pathological conditions.
Collapse
|
80
|
Jahn K, Schlesinger F, Jin LJ, Dengler R, Bufler J, Krampfl K. Molecular mechanisms of interaction between the neuroprotective substance riluzole and GABA(A)-receptors. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2008; 378:53-63. [PMID: 18458879 DOI: 10.1007/s00210-008-0290-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Accepted: 03/26/2008] [Indexed: 11/28/2022]
Abstract
The antiepileptic drug riluzole is used as a therapeutic agent in amyotrophic lateral sclerosis due to its neuroprotective effects. Besides presynaptic inhibition of GABAergic and preferentially glutamatergic transmission, it also potentiates postsynaptic GABA(A)-receptor function. We investigated the postsynaptic effects of riluzole on GABA(A)-receptor channels by use of the patch-clamp technique. Recombinant alpha1beta2gamma(2s) and alpha1beta2 GABA(A) receptors were expressed in HEK 293 cells by transient transfection. Pulses of GABA were applied in combination with different concentrations of riluzole to whole cell or outside-out patches with either alpha1beta2gamma(2s) or alpha1beta2 GABA(A)-receptor channels. Co-application of riluzole led to a slight decrease of absolute peak current amplitudes and steady-state currents in prolonged presence of GABA at saturating concentrations. In the presence of riluzole, enhancement of current amplitudes was observed with lower concentrations of GABA at alpha1beta2gamma(2s) receptors and to a lower extent also at alpha1beta2 receptors. Thus, the potentiating effect of riluzole was shown to be not abolished in the absence of the gamma(2s)-subunit. A further prominent effect of riluzole was a highly significant acceleration of the time course of current decay, most probably pointing to an open-channel block-like mechanism of action. As both receptor subtypes were affected similarly by the block, it could be concluded that the respective binding sites should be assumed within a region of high sequence homology like it is given for the channel-lining M2 domain of GABA(A)-receptor subunits. In conclusion, three different molecular mechanisms of interaction of the neuroprotective compound riluzole were observed at two different subtypes of GABA(A) receptor channels. The results further point to the impact of the inhibitory as well as the excitatory synaptic activity as a pharmacological target to counteract chronic excitotoxicity and reveal molecular mechanisms of action of the only one neuroprotective drug in current clinical use in patients suffering from amyotrophic lateral sclerosis.
Collapse
|
81
|
Schrader C, Peschel T, Däuper J, Rollnik J, Dengler R, Kossev A. Changes in processing of proprioceptive information in Parkinson’s disease and multiple system atrophy. Clin Neurophysiol 2008; 119:1139-46. [DOI: 10.1016/j.clinph.2008.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 12/29/2007] [Accepted: 01/10/2008] [Indexed: 10/22/2022]
|
82
|
Bufler J, Dengler R. Editorial. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
83
|
Staude G, Wolf W, Wierzbicka M, Oertel W, Dengler R. Die Abhängigkeit schneller willkürlicher Kontraktionen von der Tremorphase beim Parkinsonismus. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
84
|
Tröger M, Dengler R. Neurophysiologische Diagnostik bei amyotropher Lateralsklerose. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
85
|
Dengler R, Elek J, Hermans R, Wolf W. Doppelentladungen motorischer Einheiten und Tremorstärke. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
86
|
Dengler R, Struppler A. Beurteilung der Lokalisation und Ausdehnung von Hirnstammaffektionen mit Hilfe des Orbicularis-oculi-Reflexes. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1061091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
87
|
Dengler R, Stein R. Direkte Messung der Leitgeschwindigkeit einzelner motorischer Axone am Menschen. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
88
|
Dengler R, Heinze HJ, Rappelsberger P, Ringelstein E, Speckmann EJ, Stöhr M, Wieser HG. Editorial. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
89
|
Dengler R. Stand und Entwicklungen der modernen klinischen Elektromyographie. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
90
|
Wohlfarth K, Dengler R, Kossev A, Elek J, Schubert M, Wolf W. Ist die F-Wellen-Entstehung abhängig von der Größe der motorischen Einheiten? KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
91
|
Schubert M, Mills K, Boniface S, Konstanzer A, Dengler R. Veränderungen der Reizantworten motorischer Einheiten auf transkranielle Magnetstimulation bei Patienten mit multipler Sklerose und zerebralem Insult. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
92
|
Dengler R, Rechl F, Struppler A. Überlegungen zur Funktion der frühen und späten Komponente des Blinkreflexes - Untersuchung des Entladungsverhaltens einzelner motorischer Einheiten. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1061039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
93
|
Dengler R, Wolf W, Schubert M, Struppler A. Störungen der Entladungstätigkeit motorischer Einheiten beim Parkinsonismus. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
94
|
Nikolova Z, Moebes J, Arsic M, Dengler R, Scroeder C. Processing of emotional prosody in patients with primary cervical dystonia. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
95
|
Dethlefsen C, Edler B, Nogueira W, Buechner A, Muente T, Lenarz T, Dengler R, Nager W. Simulation of a cochlear implant device diminishes the electrophysiological auditory orienting reaction to speech. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
96
|
Arsic M, Möbes J, Nikolova Z, Wittfoth M, Dengler R, Schröder C. Influence of valence and arousal on emotional prosody processing: ERP study. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
97
|
Grosskreutz J, Kaufmann J, Heil R, Bodammer N, Dengler R, Peschel T. Brain endophenotype of extremity and bulbar onset ALS in diffusion tensor imaging. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
98
|
Mohammadi B, Kollewe K, Krampfl K, Samii A, Dengler R, Münte T. Cortical and subcortical motor activity in patients with sporadic ALS studied with fMRI. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
99
|
Mohammadi B, Schedel I, Graf K, Teiwes A, Hecker H, Haameijer B, Scheinichen D, Piepenbrock S, Dengler R, Bufler J. Role of endotoxin in the pathogenesis of critical illness polyneuropathy. J Neurol 2008; 255:265-72. [PMID: 18283402 DOI: 10.1007/s00415-008-0722-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 07/13/2007] [Accepted: 08/21/2007] [Indexed: 10/22/2022]
Abstract
Critical illness polyneuropathy (CIP) occurs in association with sepsis and multiple organ failure; however, little is known about the pathomechanisms of CIP and its therapy. In order to determine the parameters which interfere with development of CIP, electrophysiological investigations of peripheral nerves and biochemical measures were correlated to each other. The present study includes 20 consecutive patients in an intensive care unit developing severe sepsis or septic shock. Nerve conduction studies and electromyography were performed with occurring sepsis (day 1, 7, 14) and neurophysiological parameters were correlated with biochemical measures, especially indicators of infection and inflammation. It was found that all patients developed neurophysiological signs of axonal motor polyneuropathy. There was a significant correlation between serum concentrations of endotoxin and interleukin-2 receptors (IL2-R) and reduction of the amplitude of the compound motor action potentials. Other clinical and biochemical parameters showed no significant correlations with neurophysiological data. This finding apparently indicates that endotoxin damages nerve axons directly or indirectly, e.g. by activation of inflammatory cascades (IL2-R). Endotoxin appears to be an essential factor in the pathogenesis of CIP in sepsis, and therapeutic options neutralizing endotoxin may prevent development of CIP.
Collapse
|
100
|
|