Search results for "TRPV1"
showing 10 items of 17 documents
The endocannabinoid N-arachidonoyldopamine (NADA) exerts neuroprotective effects after excitotoxic neuronal damage via cannabinoid receptor 1 (CB(1)).
2012
Endocannabinoids exert numerous effects in the CNS under physiological and pathological conditions. The aim of the present study was to examine whether the endocannabinoid N-arachidonoyldopamine (NADA) may protect neurons in excitotoxically lesioned organotypic hippocampal slice cultures (OHSC). OHSC were excitotoxically lesioned by application of N-methyl-d-aspartate (NMDA, 50 μM) for 4 h and subsequently treated with different NADA concentrations (0.1 pM-50 μM) alone or in combination with cannabinoid receptor antagonists. NADA protected dentate gyrus granule cells and caused a slight reduction in the number of microglial cells. The number of degenerated neurons significantly decreased be…
Co-expression of the voltage-gated potassium channel Kv1.4 with transient receptor potential channels (TRPV1 and TRPV2) and the cannabinoid receptor …
2006
Potassium channels contribute to basic neuronal excitability and modulation. Here, we examined expression patterns of the voltage-gated potassium channel Kv1.4, the nociceptive transduction channels TRPV1 and TRPV2 as well as the putative anti-nociceptive cannabinoid receptor CB1 by immunofluorescence double-labelings in sections of rat dorsal root ganglia (DRGs). Kv1.4, TRPV1 and CB1 were each detected in about one third of neurons (35.7+/-0.5%, 29.4+/-1.1% and 36.4+/-0.5%, respectively, mean diameter 19.1+/-0.3 microm). TRPV2 was present in 4.4+/-0.4% of all neurons that were significantly larger in diameter (27.4+/-0.7 microm; P < 0.001). Antibody double-labeling revealed that the majori…
Bioactive Oleic Derivatives of Dopamine: A Review of the Therapeutic Potential
2018
Lipid derivatives of dopamine are a novel class of compounds raising a research interest due to the potential of their being a vehicle for dopamine delivery to the brain. The aim of the present paper is to review the main features of the two most prominent bioactive members of this family, namely, N-oleoyl-dopamine (OLDA) and 3′-O-methyl-N-oleoyl-dopamine (OMe-OLDA), with emphasis on the possible therapeutic properties.
Effects of Anandamide and Noxious Heat on Intracellular Calcium Concentration in Nociceptive DRG Neurons of Rats
2007
As an endogenous agonist at the cannabinoid receptor CB1 and the capsaicin-receptor TRPV1, anandamide may exert both anti- and pronociceptive actions. Therefore we studied the effects of anandamide and other activators of both receptors on changes in free cytosolic calcium ([Ca2+]i) in acutely dissociated small dorsal root ganglion neurons (diameter: ≤30 μm). Anandamide (10 μM) increased [Ca2+]iin 76% of the neurons. The EC50was 7.41 μM, the Hill slope was 2.15 ± 0.43 (mean ± SE). This increase was blocked by the competitive TRPV1-antagonist capsazepine (10 μM) and in Ca2+-free extracellular solution. Neither exclusion of voltage-gated sodium channels nor additional blockade of voltage-gate…
Involvement of TRPV1 channels in the activity of the cannabinoid WIN 55,212-2 in an acute rat model of temporal lobe epilepsy
2016
The exogenous cannabinoid agonist WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN), has revealed to play a role on modulating the hyperexcitability phenomena in the hippocampus. Cannabinoid-mediated mechanisms of neuroprotection have recently been found to imply the modulation of transient receptor potential vanilloid 1 (TRPV1), a cationic channel subfamily that regulate synaptic excitation. In our study, we assessed the influence of pharmacological manipulation of TRPV1 function, alone and on WIN antiepileptic activity, in the Maximal Dentate Activation (MDA) acute model of temporal lobe epilepsy. Our r…
Neuronal nitric oxide synthase is involved in CB/TRPV1 signalling: Focus on control of hippocampal hyperexcitability
2017
Cannabinoids (CB), transient receptors potential vanilloid type 1 (TRPV1) and nitric oxide (NO) were found to be interlinked in regulating some neuronal functions such as membrane excitability and synaptic transmission. TRPV1 play a fundamental role since it represents a synaptic target for CB that triggers several downstream cellular pathways. In this regard, recent evidence report that TRPV1 could influence NO production by modulating neuronal NO synthase (nNOS) activity. In the present research, we pointed to manipulate nNOS function to assess its role on TRPV1 signalling in hyperexcitability conditions elicited in the dentate gyrus of hippocampal formation. The activation of TRPV1 recep…
Phosphorylation of extracellular signal-related protein kinase is required for rapid facilitation of heat-induced currents in rat dorsal root ganglio…
2005
A subgroup of dorsal root ganglion (DRG) neurons responds to noxious heat with an influx of cations carried by specific ion channels such as the transient receptor potential channel of the vanilloid receptor type, subtype 1 (TRPV1). Application of capsaicin induces a reversible facilitation of these currents. This facilitation could be an interaction of two agonists at their common receptor or be caused by an influx of calcium ions into the cell. Calcium influx into the cell can activate protein kinases such as the extracellular signal-related protein kinase (ERK) pathway. This study explored the kinetics, calcium-dependency and intracellular signals following application of capsaicin and l…
Co-expression of heat sensitive vanilloid receptor subtypes in rat dorsal root ganglion neurons
2003
Expression of the heat sensitive cation channels TRPV1 and TRPV2 was investigated by immunofluorescence in rat dorsal root ganglion (DRG) neurons. TRPV1-positive neurons were more frequent and had smaller diameters than TRPV2-positive neurons (35.7% vs 7.3%; 22.3 microm vs 27.6 microm), but size distributions overlapped and significant co-expression was seen in 20.7% of TRPV2-positive neurons (1.7% of all). Expression patterns did not differ between tissue sections typically used in immunocytochemistry and dissociated DRG neurons typically used in electrophysiology. Rectangular temperature pulses revealed two patterns of heat-evoked inward currents in small DRG neurons: low-threshold rapidl…
Capsaicin differentially modulates voltage-activated calcium channel currents in dorsal root ganglion neurones of rats
2005
It is discussed whether capsaicin, an agonist of the pain mediating TRPV1 receptor, decreases or increases voltage-activated calcium channel (VACC) currents (ICa(V)). ICa(V) were isolated in cultured dorsal root ganglion (DRG) neurones of rats using the whole cell patch clamp method and Ba 2+ as charge carrier. In large diameter neurones (>35Am), a concentration of 50AM was needed to reduce ICa(V) (activated by depolarizations to 0 mV) by 80%, while in small diameter neurones (30Am), the IC50 was 0.36 AM. This effect was concentration dependent with a threshold below 0.025 AM and maximal blockade (>80%) at 5AM. The current–voltage relation was shifted to the hyperpolarized direction with an…
Differential effects of anandamide on acetylcholine release in the guinea-pig ileum mediated via vanilloid and non-CB1 cannabinoid receptors
2001
The effects of anandamide on [3H]-acetylcholine release and muscle contraction were studied on the myenteric plexus-longitudinal muscle preparation of the guinea-pig ileum preincubated with [3H]-choline. Anandamide increased both basal [3H]-acetylcholine release (pEC50 6.3) and muscle tone (pEC50 6.3). The concentration-response curves for anandamide were shifted to the right by 1 μM capsazepine (pKB 7.5 and 7.6), and by the combined blockade of NK1 and NK3 tachykinin receptors with the antagonists CP99994 plus SR142801 (each 0.1 μM). The CB1 and CB2 receptor antagonists, SR141716A (1 μM) and SR144528 (30 nM), did not modify the facilitatory effects of anandamide. Anandamide inhibited the e…