Search results for "otas"

Muscarine receptors on the rat phrenic nerve, evidence for positive and negative muscarinic feedback mechanisms.

1987

Neuronal transmitter stores of the rat phrenic nerve were labelled by incubation with [3H]choline. Release of [3H]acetylcholine was elicited by electrical nerve stimulation (100 or 1500 pulses, 5 or 25 Hz) or by high potassium (27 mmol/l) and the effects of the muscarine receptor agonist oxotremorine and the antagonist scopolamine were investigated. Neither oxotremorine nor scopolamine affected the basal tritium efflux. A low concentration of oxotremorine (10 nmol/l) enhanced and a high concentration of oxotremorine (1 μol/l) reduced the electrically evoked [3H]acetylcholine release. Likewise, the high potassium-evoked [3H]acetylcholine release was reduced by a high concentration of oxotrem…

Characterization of endogenous noradrenaline release from intact and epithelium-denuded rat isolated trachea.

1991

1. Overflow of endogenous noradrenaline (NA) from the in vitro incubated rat trachea evoked by two periods of electrical field stimulation (S1, S2 at 3 or 15 Hz) or by high potassium (60 mM) was determined by high performance liquid chromatography (h.p.l.c.) with electrochemical detection. 2. In the presence of the neuronal uptake inhibitor desipramine, the alpha 2-adrenoceptor antagonist, yohimbine, enhanced the overflow of NA evoked by stimulation at 3 Hz by about 100% suggesting the presence of presynaptic inhibitory autoreceptors on the sympathetic nerves innervating the trachea. 3. When desipramine and yohimbine were present throughout the experiments, the overflow of NA evoked by the …

Model-specific effects of bumetanide on epileptiform activity in the in-vitro intact hippocampus of the newborn mouse.

2007

The immature brain has a higher susceptibility to develop seizures, which often respond poorly to classical pharmacological treatment. It has been recently suggested that bumetanide, which blocks Na(+)-dependent K(+)-Cl(-)-cotransporter isoform 1 (NKCC1) and thus attenuates depolarizing GABAergic responses, could soothe epileptiform activity in immature nervous systems. To evaluate whether bumetanide consistently attenuates epileptiform activity, we investigated the effect of 10 microM bumetanide in five different in-vitro epilepsy models using field potential recordings in the CA3 region of intact mouse hippocampal preparations at postnatal day 4-7. Bumetanide reduced amplitude and frequen…

Stimulation of calcium uptake by norepinephrine or high external potassium in human calyces and renal pelvis.

1989

The effects of stimulation with either 10 mumol/l norepinephrine or 85 mmol/l extracellular potassium concentration on calcium uptake were studied in muscle strips from human renal calyces and from the renal pelvis. The apparent uptake of calcium under control conditions was essentially complete after 30 min. Stimulation of the muscle strips with norepinephrine or high external potassium significantly (P less than 0.05) increased the calcium uptake over the control values at 30 and 100 min, whereas 45Ca efflux was virtually not affected. It is concluded that the mechanical responses of the muscle strips to norepinephrine or high external potassium correspond with an increased uptake of calc…

Differential effects of potassium channel blockers on neurohypophysial release of oxytocin and vasopressin. Evidence for frequency-dependent interact…

1988

Isolated rat neurohypophyses were fixed by their stalks to a platinum wire electrode and superfused with Krebs-HEPES solution. Vasopressin and oxytocin released into the medium were determined by specific radioimmunoassays. Hormone secretion was increased by electrical stimulation of the pituitary stalk at different frequencies. The effects of several potassium channel blockers, tetraethylammonium (TEA) ions, 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP) were tested. The release of vasopressin and oxytocin evoked by electrical stimulation with 900 pulses at 15 Hz (about 900 and 1,000 μU, respectively) was about 10 times higher than that evoked by 900 pulses at 3 Hz. Both 10 and 3…

Response by Núñez et al to Letter Regarding Article, “Long-Term Potassium Monitoring and Dynamics in Heart Failure and Risk of Mortality”

2018

Altered atrial restitution dynamics and refractoriness in metabolic syndrome due to up-regulation of potassium repolarizing currents increases suscep…

2021

Abstract Background Metabolic alterations, such as Metabolic Syndrome (MS), describe an association of factors including diabetes, hypertension, obesity and dyslipidemia, linked to higher risk and prevalence of overall cardiovascular disease, arrhythmogenesis and sudden cardiac death. Obese and diabetic patients have shown an increased risk for developing atrial fibrillation (AF). However, underlying mechanisms are not understood. Purpose To study the effects of MS and obesity remodeling in atrial restitution dynamics, frequency-dependent adaptation, refractoriness and its potential susceptibility to AF. Methods Electrophysiological experimental data from High-fat (HF-O, standard rabbit cho…

A clinical study of the effect of calcium sodium phosphosilicate on dentin hypersensitivity

2012

Objective: Dentinal hypersensitivity is a commonly encountered problem with varied treatment options for its management. A large number of home use products have been tested and used for the management of dentinal hypersensitivity. This 8 week clinical trial investigates the temporal efficacy of commercially available calcium sodium phosphosilicate containing toothpaste in comparison to a potassium nitrate containing toothpaste. Methods: A total 20 subjects between the ages of 18 to 65 years were screened for a visual analogue score (VAS) for sensitivity of 5 or more by testing with a cold stimulus and randomly divided into test and positive control groups. Baseline sensitivity VAS scores t…

intelektuālā īpašuma aizsardzība muitas iestādē.

2017

Maģistra darbs „Intelektuālā īpašuma aizsardzība muitas iestādē” sniedz ieskatu Latvijas tiesību sistēmā pastāvošajās problēmās attiecībā uz intelektuālā īpašuma tiesību aizsardzību muitā, salīdzinot muitas iestāžu darbību intelektuālā īpašuma tiesību aizsardzības jomā Latvijā un citās Eiropas Savienības dalībvalstīs. Darbs kopumā ir sadalīts trīs nodaļās, sākot ar intelektuālā īpašuma tiesību un viltoto preču jēdzienu analīzi un jautājuma par intelektuālā īpašuma tiesību tvērumu muitas darbību reglamentējošos normatīvajos aktos izpēti, turpinot ar pārkāpuma preču konstatēšanas kārtību Valsts ieņēmumu dienestā, un beidzot ar izvērstu muitas darbību reglamentējošo normatīvo aktu piemērošanas…

Hypokalemic rhabdomyolysis associated with Bartter's syndrome.

1983

Severe potassium deficiency is an uncommon cause of rhabdomyolysis. We recently treated a 45-year-old patient with myalgia, serious generalized weakness, increased serum creatine kinase and myoglobin level as well as excessive hypokalemia. Histological examination of deltoid muscle biopsy showed rhabdomyolysis. After complete recovery of muscle damage by potassium substitution Bartter's syndrome proved to be the cause of initial and persistent hypokalemia.