Search results for "STIMULATION"
showing 10 items of 2192 documents
NK1- and NK3-receptor mediated inhibition of 5-hydroxytryptamine release from the vascularly perfused small intestine of the guinea-pig
1997
The effects of tachykinins on the spontaneous release of 5-hydroxytryptamine (5-HT) from the enterochromaffin cells into the portal circulation was investigated in vitro using the vascularly perfused isolated guinea-pig small intestine. 5-HT was determined by HPLC with electrochemical detection. Test substances were applied intraarterially. Substance P (SP) caused a concentration-dependent decrease in 5-HT outflow with an EC50 of 50 pmol/l. Similarly, the selective NK1 receptor agonist SP methyl ester (1 nmol/l) significantly inhibited 5-HT outflow (to 51 +/- 3%). When tetrodotoxin (1 mumol/l) was added to the arterial perfusion medium, the inhibition by SP of 5-HT outflow was not affected.…
Increase by 5-hydroxykynuramine of spontaneous acetylcholine release from myenteric neurons: mediated by serotonin M receptors
1987
The effects of 5-hydroxykynuramine (5-OH-K) and of 3-(2-amino-5-hydroxyphenyl)-propaneamine (AHPP) on spontaneous and electrically evoked release of [3H]acetylcholine were studied in the guinea-pig myenteric plexus longitudinal muscle preparation preincubated with [3H]choline. 5-OH-K caused a concentration-dependent increase in spontaneous [3H]acetylcholine release (EC50 5.3 microM). This effect was diminished in the presence of a desensitizing concentration of 5-hydroxytryptamine (5-HT). AHPP (1-100 microM) did not affect the spontaneous outflow of [3H]acetylcholine. The electrically evoked release of [3H]acetylcholine was significantly reduced in the presence of 100 microM of either 5-OH-…
STIMULATION OF ?1-ADRENOCEPTORS ENHANCES ELECTRICALLY EVOKED [3H]-ACETYLCHOLINE RELEASE FROM RAT PHRENIC NERVE
1990
1. The effects of isoprenaline, noradrenaline and fenoterol on the electrically evoked release of [3H]-acetylcholine from the rat phrenic nerve were investigated. 2. Isoprenaline (0.1 mumol/L) and noradrenaline (1 mumol/L) enhanced evoked [3H]-acetylcholine release by about 90%, an effect which was abolished by CGP 20712A (0.1 mumol/L), a specific antagonist at beta 1-adrenoceptors. Noradrenaline still enhanced [3H]-acetylcholine release in the presence of phentolamine (1 mumol/L). 3. The enhancing effect of both isoprenaline and noradrenaline decreased at prolonged exposure times (24-32 min). A pre-exposure of the tissue to a low concentration (0.01 mumol/L) of isoprenaline prevented the e…
The effects of several muscarinic antagonists on pre- and postsynaptic receptors in the isolated rabbit heart
1981
In order to reveal possible differences between pre- and postsynaptic muscarine receptors, seven antagonists were tested for their affinities on these receptor sites in the rabbit isolated perfused heart. Methacholine was used as an agonist to inhibit the noradrenaline overflow evoked by electrical stimulation (3 Hz, 3 min) of the sympathetic nerves (presynaptic parameter) and to decrease the systolic tension development of the right atrium (postsynaptic parameter). The affinity of an antagonist was expressed as pA2. A decreasing order of potency was obtained with ipratropium, scopolamine, atropine, trihexyphenidyl, amitriptyline, and gallamine, both for pre- and postsynaptic responses. The…
Different electrophysiological actions of 24- and 72-hour aggregated amyloid-beta oligomers on hippocampal field population spike in both anesthetize…
2010
Diffusible oligomeric assemblies of the amyloid beta-protein (Abeta) could be the primary factor in the pathogenic pathway leading to Alzheimer's disease (AD). Converging lines of evidence support the notion that AD begins with subtle alterations in synaptic efficacy, prior to the occurrence of extensive neuronal degeneration. Recently, however, a shared or overlapping pathogenesis for AD and epileptic seizures occurred as aberrant neuronal hyperexcitability, as well as nonconvulsive seizure activity were found in several different APP transgenic mouse lines. This generated a renewed attention to the well-known comorbidity of AD and epilepsy and interest in how Abeta oligomers influence neu…
Continuous theta burst stimulation (cTBS) on left cerebellar hemisphere affects mental rotation tasks during music listening.
2013
Converging evidence suggests an association between spatial and music domains. A cerebellar role in music-related information processing as well as in spatial-temporal tasks has been documented. Here, we investigated the cerebellar role in the association between spatial and musical domains, by testing performances in embodied (EMR) or abstract (AMR) mental rotation tasks of subjects listening Mozart Sonata K.448, which is reported to improve spatial-temporal reasoning, in the presence or in the absence of continuous theta burst stimulation (cTBS) of the left cerebellar hemisphere. In the absence of cerebellar cTBS, music listening did not influence either MR task, thus not revealing a “Moz…
Neuromuscular Fatigue Is Not Different between Constant and Variable Frequency Stimulation
2014
International audience; This study compared fatigue development of the triceps surae induced by two electrical stimulation protocols composed of constant and variable frequency trains (CFTs, VFTs, 450 trains, 30 Hz, 167 ms ON, 500 ms OFF and 146 ms ON, 500 ms OFF respectively). For the VFTs protocol a doublet (100 Hz) was used at the beginning of each train. The intensity used evoked 30% of a maximal voluntary contraction (MVC) and was defined using CFTs. Neuromuscular tests were performed before and after each protocol. Changes in excitation-contraction coupling were assessed by analysing the M-wave [at rest (M-max) and during MVC (M-sup)] and associated peak twitch (Pt). H-reflex [at rest…
Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver
2001
The effects of a water-soluble extract (WSE) of rosemary and its purified antioxidant rosmarinic acid (RA) on xenobiotic metabolizing enzymes (XME) were studied in rat liver after dietary administration. The modulation of phase I enzymes such as cytochrome P450 (CYP) 1A, 2B, 2E1, 3A, and phase II enzymes such as glutathione S-transferase (GST), quinone reductase (QR) and UDP-glucuronosyltransferase (UGT) was evaluated by measuring enzyme activities with specific substrates. Protein levels of CYPs and rGST A1/A2, A3/A5, M1, M2 and P1 were measured using antibodies in Western blots. Caffeic acid was also studied because it results from RA biotransformation in rat after oral administration. Ma…
Study on the Acceptability of an ICT Platform for Older Adults with Mild Cognitive Impairment
2020
EhcoBUTLER is an Information and Communication Technology (ICT) solution funded by the European Union (H2020; ID: 643566) and intended especially for elderly people with mild cognitive impairment (MCI) to improve their health, independence and quality of life, particularly at the social level. The purpose of this study is to assess the acceptability of ehcoBUTLER based on a survey delivered to potential users and actors involved in their care, exploring their expectations and preferences, while anticipating the system’s functional requirements. The survey was delivered online to 313 participants (11% end users, 25% informal caregivers, 48% formal caregivers and 16% administration/management…
Activation of L-arginine transport by protein kinase C in rabbit, rat and mouse alveolar macrophages
1998
1 The role of protein kinase C in controlling L-arginine transport in alveolar macrophages was investigated. 2 L-[3H]Arginine uptake in rabbit alveolar macrophages declined by 80 % after 20 h in culture. 4β-Phorbol 12-myristate 13-acetate (PMA), but not 4α-phorbol 12-myristate 13-acetate (α-PMA), present during 20 h culture, enhanced L-[3H]arginine uptake more than 10-fold. Staurosporine and chelerythrine opposed this effect. 3 L-[3H]Arginine uptake was saturable and blockable by L-lysine. After PMA treatment Vmax was increased more than 5-fold and Km was reduced from 0.65 to 0.32 mM. 4 Time course experiments showed that PMA increased L-[3H]arginine uptake almost maximally within 2 h. This…