A5019900607- Neuropeptides and Animal Physiology
- Receptor Mechanisms and Signaling
- Adenosine and Purinergic Signaling
- Neuroscience of respiration and sleep
- Nitric Oxide and Endothelin Effects
- Pain Mechanisms and Treatments
- Neuroendocrine regulation and behavior
- Neuroscience and Neuropharmacology Research
- Ion channel regulation and function
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Pharmacological Receptor Mechanisms and Effects
- Cardiovascular, Neuropeptides, and Oxidative Stress Research
- Trace Elements in Health
- Neurotransmitter Receptor Influence on Behavior
- Heart Rate Variability and Autonomic Control
- Biochemical effects in animals
- Hypothalamic control of reproductive hormones
- Renin-Angiotensin System Studies
- Anesthesia and Pain Management
- Pharmacological Effects and Toxicity Studies
- Pharmacological Effects and Assays
- Chemical Synthesis and Analysis
- Prion Diseases and Protein Misfolding
- Cardiovascular Issues in Pregnancy
- Ion Channels and Receptors
Universidad de Santiago de Chile
2014-2024
Millennium Initiative for Collaborative Research on Bacterial Resistance
2018-2021
Pontificia Universidad Católica de Chile
2005-2014
Eunice Kennedy Shriver National Institute of Child Health and Human Development
2011
National Institutes of Health
2011
Charles University
2011
Universidad Andrés Bello
2006-2009
Millennium Institute for Integrative Biology
2001-2007
University of Chile
1976-2006
Universidade Federal de Santa Catarina
1995-2002
Amide derivatives of fatty acids were recently isolated from cerebrospinal fluid sleep-deprived animals and found to induce sleep in rats. To determine which brain receptors might be sensitive these novel neuromodulators, we tested them on a range expressed Xenopus oocytes. cis-9,10-Octadecenamide (ODA) markedly potentiated the action 5-hydroxytryptamine (5-HT) 5-HT2A 5-HT2C receptors, but this was not shared by related compounds such as oleic acid trans-9,10-octacenamide. ODA active at...
In the isolated rat mesenteric bed, 1 min perfusion with 100 nm anandamide, a concentration that did not evoke vasorelaxation, elicited an acute release of 165.1 +/- 9.2 pmol nitric oxide (NO) was paralleled by 2-fold increase in cGMP tissue levels. The rise NO released mimicked either (R)-(+)-methanandamide or vanilloid receptor agonists resiniferatoxin and (E)-capsaicin but its inactive cis-isomer (Z)-capsaicin. anandamide capsaicin reduced TRPV1 antagonists 5'-iodoresiniferatoxin, SB...
Interaction of intoxicant-anesthetic drugs with the gamma-aminobutyric acid (GABA) receptor-chloride channel complex mouse brain was studied using binding [35S]t-butylbicyclophosphorothionate (TBPS) to isolated membranes and GABA-stimulated uptake 36Cl- by membrane vesicles. Anesthetic drugs, including barbiturates, chloroform, diethylether ethanol, inhibited TBPS enhanced GABA-dependent influx chloride. In presence bicuculline, barbiturates increased TBPS, but this action not shared other...
Abstract The P2X 7 receptor is a non‐selective cationic channel activated by extracellular ATP, belonging to the family. To assess role of histidines on allosteric modulation rat divalent metals (copper, zinc and magnesium) protons, these amino acid residues were singly substituted for corresponding alanines. Wild‐type mutated receptors injected Xenopus laevis oocytes; metal‐related effects evaluated two‐electrode voltage‐clamp technique. Copper inhibited ATP‐gated currents with median...
The P2X7 receptor, a member of the P2X purinergic receptor family, is non-selective ion channel. Over years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation captured scientific community's attention. This function essential for immune system identify and respond external threats, such as pathogens tumor cells, through T lymphocytes. New studies show that crucial controlling how antigens...
To assess the role of nucleotide receptors in endothelial‐smooth muscle signalling, changes perfusion pressure rat arterial mesenteric bed, luminal output nitric oxide (NO) and guanosine 3′,5′ cyclic monophosphate (cGMP) accumulation were measured after nucleotides. The rank order potency ATP analogues causing relaxation precontracted mesenteries was: 2‐MeSADP=2‐MeSATP>ADP>ATP=UDP=UTP>adenosine. vasodilatation was coupled to a concentration–dependent rise NO cGMP production. MRS...
Abstract: The rat ATP P2X 4 receptor was expressed in Xenopus laevis oocytes to assess the effect of zinc and copper as possible regulators purinergic mechanisms. applied for 20 s evoked an inward cationic current with a median effective concentration (EC 50 ) 21.4 ± 2.8 μ M Hill coefficient ( n H 1.5 0.1. Coapplication plus 10 displaced leftward, parallel fashion, concentration‐response curve, reducing EC 8.4 1.8 p < 0.01) without altering . potentiation fast onset, easily reversible,...
To assess the involvement of endothelial α 2 ‐adrenoceptors in clonidine‐induced vasodilatation, mesenteric artery Sprague Dawley rats was cannulated and perfused with Tyrode solution (2 ml min −1 ). We measured perfusion pressure, nitric oxide (NO) perfusate using chemiluminescence, tissue cyclic GMP by RIA. In phenylephrine‐precontracted mesenteries, clonidine elicited concentration‐dependent vasodilatations associated to a rise luminal NO. One hundred n M rauwolscine or 100 μ L ω ‐nitro‐...
The pharmacological profile of a series (±)‐2,5‐dimethoxy‐4‐(X)‐phenylisopropylamines (X=I, Br, NO 2 , CH 3 or H) and corresponding phenylethylamines, was determined in Xenopus laevis oocytes injected with cRNA coding for rat 5‐HT 2A 2C receptors. efficacy relative potency these drugs were compared to classical receptor agonists antagonists. rank order agonist at the was: α‐methyl‐5‐HT=5‐HT> m ‐CPP>MK‐212; 5‐HT>α‐methyl‐5‐HT>MK‐212> ‐CPP. All compounds full receptor, but...
The effect of bradykinin on the neuroeffector junction isolated rat vas deferens was studied in tissues stimulated transmurally at a frequency 0.15 Hz. Bradykinin caused two distinct and independent actions: it potentiated magnitude muscular response to electrically driven twitches and, addition, contracted smooth muscle generating an increased tone. former action is referred as neurogenic or presynaptic effect, whereas latter called musculotropic postjunctional action. abolished by...
Epinephrine plays a key role in the control of vasomotor tone; however, participation NO/cGMP pathway response to beta-adrenoceptor activation remains controversial. To evaluate involvement endothelium vascular epinephrine, we assessed NO production, endothelial synthase phosphorylation, and tissue accumulation cGMP perfused arterial mesenteric bed rat. elicited concentration-dependent increase (EC(50) 45.7 pM), which was coupled accumulation. Both production were blocked by either removal...
Zn2+ is an essential ion that stored in and co-released from glutamatergic synapses it modulates neurotransmitter receptors involved long-term potentiation (LTP). However, the mechanism(s) underlying Zn2+-induced modulation of LTP remain(s) unclear. As purinergic P2X are relevant targets for action, we have studied their role by CA1 region rat hippocampal slices. Induction presence revealed a biphasic effect – 5–50 μm enhanced induction, whereas 100–300 inhibited LTP. The involvement...
The 5′untranslated regions (UTR) of the full length mRNA HIV-1 proviral clones pNL4.3 and pLAI, harbor an internal ribosomal entry site (IRES). In this study we extend finding by demonstrating that 5′UTRs natural variants also exhibit IRES-activity. Cap-independent translational activity was demonstrated using bicistronic mRNAs in HeLa cells Xenopus laevis oocytes. possibility expression downstream cistron these constructs due to alternative splicing or cryptic promoter ruled out. exhibited...