Search results for "Elea"
showing 10 items of 772 documents
Presynaptic effects of anandamide and WIN55,212-2 on glutamatergic nerve endings isolated from rat hippocampus
2006
We examined the effects of the endocannabinoide-anandamide (AEA), the synthetic cannabinoid, WIN55,212-2, and the active phorbol ester, 4-beta-phorbol 12-myristate 13-acetate (4-beta-PMA), on the release of [(3)H]d-Aspartate ([(3)H]d-ASP) from rat hippocampal synaptosomes. Release was evoked with three different stimuli: (1) KCl-induced membrane depolarization, which activates voltage-dependent Ca(2+) channels and causes limited neurotransmitter exocytosis, presumably from ready-releasable vesicles docked in the active zone; (2) exposure to the Ca(2+) ionophore-A23187, which causes more extensive transmitter release, presumably from intracellular reserve vesicles; and (3) K(+) channel block…
Role of calcineurin in Ca2+-induced release of catecholamines and neuropeptides
1998
Neurotransmission requires rapid docking, fusion, and recycling of neurotransmitter vesicles. Several of the proteins involved in this complex Ca2+-regulated mechanism have been identified as substrates for protein kinases and phosphatases, e.g., the synapsins, synaptotagmin, rabphilin3A, synaptobrevin, munc18, MARCKS, dynamin I, and B-50/GAP-43. So far most attention has focused on the role of kinases in the release processes, but recent evidence indicates that phosphatases may be as important. Therefore, we investigated the role of the Ca2+/calmodulin-dependent protein phosphatase calcineurin in exocytosis and subsequent vesicle recycling. Calcineurin-neutralizing antibodies, which blocke…
Role of central oxytocin in the inhibition by endotoxin of distension-stimulated gastric acid secretion
2000
The gastric acid hyposecretory state associated with endotoxemia is mediated by a nervous reflex involving the central nervous system. The aim of the present study was to analyse the central effects of different peptides on distension-stimulated gastric acid secretion and the endogenous role of such peptides on the hyposecretory effects of endotoxin. The effect of an intracisternal (i.c.) administration of oxytocin, vasopressin, corticotropin releasing factor (CRF), bombesin, somatostatin and the opioid receptor agonist BW443C or an intravenous (i.v.) injection of a small dose of endotoxin on distension-stimulated gastric acid secretion was studied in the continuously perfused stomach of an…
BRAIN-TARGETED SOLID LIPID NANOPARTICLES CONTAINING RILUZOLE: PREPARATION, CHARACTERIZATION AND BIODISTRIBUTION
2009
Aim: Developments within nanomedicine have revealed a great potential for drug delivery to the brain. In this study nanoparticulate systems as drug carriers for riluzole, with sufficiently high loading capacity and small particle size, were prepared to a reach therapeutic drug level in the brain. Materials & method: Solid lipid nanoparticles containing riluzole have great potential as drug-delivery systems for amyotrophic lateral sclerosis and were produced by using the warm oil-in-water microemulsion technique. The resulting systems obtained were approximately 88 nm in size and negatively charged. Drug-release profiles demonstrated that a drug release was dependent on medium pH. Biodi…
Characterization of a Ryanodine Receptor inPeriplaneta Americana
1997
Specific binding sites for the alkaloid ryanodine were characterized in membrane preparations from sarcoplasmatic reticulum of Periplaneta americana skeletal muscle. Binding of [3H]ryanodine was optimal at pH 8 and at CaCl2 concentration of about 300 mumol l-1. The Ca-chelating agents EGTA (100 mumol l-1) and EDTA (100 mumol l-1) abolished 95% and 90% of the [3H]ryanodine binding respectively. Preincubation with Ca2+ (100 mumol l-1) restored the ryanodine binding in presence of up to 300 mumol l-1 EGTA. Radioligand binding experiments showed one class of high affinity binding sites for ryanodine. Determination of rate constants revealed 7.05 x 10(6) l mol-1 min-1 for associating and 3.77 x …
OnabotulinumtoxinA: how deep will it go?
2014
First-line treatment of overactive bladder syndrome (OAB) is based on conservative measures and oral medication such asmuscarinic receptor antagonists and, more recently, b3-adrenoceptor agonists.While this provides effective symptom relief for many patients, for others it has insufficient efficacy and/or intolerable side effects. The potent neurotoxin onabotulinumtoxinA (BoNT-A) has shown efficacy in placebo-controlled trials in patients with neurogenic voiding dysfunction or OAB [1], largely including patients exhibiting an insufficient treatment response to muscarinic antagonists. Although the role of a strong placebo component in the beneficial effects of oral treatment is well known, a…
Selective bilateral blood sampling from the inferior petrosal sinus in Cushing's disease: effects of corticotropin-releasing factor and thyrotropin-r…
1993
We sought to enhance the sensitivity of selective bilateral blood sampling to determine adrenocorticotropin (ACTH) and prolactin levels in the inferior petrosal sinus (IPS) by administering two stimulatory agents--corticotropin-releasing factor (CRF) and thyrotropin-releasing hormone (TRH). We then determined the ACTH and prolactin levels in the IPS of 10 patients with Cushing's disease. After peripheral administration of both CRF and TRH, ACTH levels were significantly higher on the tumor side in all patients. The prolactin level was significantly higher on the tumor side when CRF or TRH was used to stimulate pituitary secretion. Postsurgical immunohistochemistry studies revealed productio…
Ethanol Modulates Corticotropin Releasing Hormone Release From the Rat Hypothalamus: Does Acetaldehyde Play a Role?
2010
BACKGROUND AND METHODS Ethanol (EtOH) activates hypothalamic-pituitary-adrenal (HPA) axis, resulting in adrenocorticotropin hormone, glucocorticoid release, and in modifications of the response of the axis to other stressors. The initial site of EtOH action within the HPA system seems to be the hypothalamus. Thus, to determine the mechanisms responsible for these effects, we investigated: (i) whether EtOH was able to release corticotrophic releasing hormone (CRH) from incubated hypothalamic explants; (ii) whether acetaldehyde (ACD), its first metabolite formed in the brain by catalase activity, might play a role in EtOH activity. To this aim, rat hypothalamic explants were incubated with: (…
Treatment of cryptorchidism with a potent analog of gonadotropin-releasing hormone.
1978
Pernasal therapy of cryptorchidism with D-Leu6-des-Gly10-gonadotropin-releasing hormone ethylamide (D-Leu6-des-Gly10-GnRH-EA), a potent, long-acting GnRH analog, was attempted. Eleven prepubertal cryptorchid boys received between 25 microgram once daily and 25 to 50 microgram twice daily for 5 to 12 weeks. Complete testicular descent was achieved in 4 of the 11 boys. GnRH tests (1.5 microgram/kg intravenously), conducted in six boys before treatment, after 4 weeks of treatment, and in 2 boys 3 months after treatment, did not reveal changes in gonadotropin secretion indicative of precocious puberty or of decreased hypophyseal sensitivity to GnRH. Antibodies to the GnRH analog or to GnRH coul…
Correlation between severity of growth hormone deficiency and thyroid metabolism and effects of long-term growth hormone treatment on thyroid functio…
2013
<b><i>Background/Aim:</i></b> The significance of changes in thyroid function in children during growth hormone (GH) treatment remains uncertain. We aimed to evaluate the impact of GH replacement on thyroid status in children with idiopathic GH deficiency (GHD). <b><i>Methods:</i></b> Data of 105 GHD children (82 M, 23 F; aged 11.13 years) during a 36-month follow-up were analyzed. At diagnosis the areas under the curve of GH (AUC<sub>GH</sub>) were calculated during a GH-releasing hormone + arginine (GHRH-Arg) and insulin tolerance test. <b><i>Results:</i></b> A significant &#x0394;fT<sub>3</su…