Search results for "choline"
showing 10 items of 1138 documents
Effects of Long-Term Nitroglycerin Treatment on Endothelial Nitric Oxide Synthase (NOS III) Gene Expression, NOS III–Mediated Superoxide Production, …
2000
Abstract —Long-term nitroglycerin (NTG) treatment has been shown to be associated with cross-tolerance to endothelium-dependent vasodilators. It may involve increased production of reactive oxygen species (such as superoxide, O 2 ·− ) that rapidly inactivate the nitric oxide (NO) released from the endothelial cells. It remains to be elucidated, however, whether long-term treatment with NTG alters the activity and expression of the endothelial NO synthase (NOS III) and whether this enzyme can contribute to O 2 ·− formation. We studied the influence of long-term NTG treatment on the expression of NOS III as assessed by RNase protection assay and Western blot. Tolerance was measured ex vivo i…
Effects of diazinon exposure on cholinesterase activity in different tissues of European eel (Anguilla anguilla).
1996
Cholinesterase (ChE) activity was measured in brain, plasma, and whole eye of Anguilla anguilla experimentally exposed to a sublethal concentration of 0.042 mg/liter (0.50 of the 96-hr LC50) of the organophosphorous pesticide diazinon. Whole eye was the tissue which revealed higher values of ChE activity (8.17 micromol/min/g) in nonexposed animals. Brain, plasma, and whole eye ChE activity of A. anguilla was inhibited at 6, 24, 48, 72, and 96 hr of diazinon exposure. Pesticide induced significant inhibitory effects on the ChE activity of this species ranging from >70% inhibition in brain tissue to >90% in plasma samples. Brain and plasma presented technical difficulties in their collection.…
In vivo inhibition of AChE activity in the European eel Anguilla anguilla exposed to technical grade fenitrothion.
1998
European eel (Anguilla anguilla) were exposed to sublethal fenitrothion concentrations in a continuous flow-through system for 4 days. Plasma acetylcholinesterase (AChE) activity was evaluated after 2, 8, 12, 24, 32, 48, 56, 72 and 96 h pesticide exposure. AChE activity in the plasma of the eel decreased as concentration of fenitrothion increased. Pesticide induced significant inhibitory effects on the AChE activity of A. anguilla ranging from 51% inhibition at sublethal concentration of 0.02 ppm to 57% inhibition at sublethal concentration of 0.04 ppm. Eel were exposed to both fenitrothion concentrations for 96 h and then allowed a period of recovery in pesticide-free water. Following 1 we…
NMDA-induced acetylcholine release in mouse striatum: role of NO synthase isoforms
2002
Striatal cholinergic interneurons are stimulated by glutamatergic inputs from thalamus and cortex via NMDA receptors. The present microdialysis study was designed to characterize the role of nitric oxide (NO) in this process and to identify the NO synthase (NOS) isoform responsible for this effect. For this purpose, we studied the effects of NMDA and 3-morpholino sydnonimine (SIN-1) perfusions on the release of acetylcholine (ACh) in mouse striatum. In wild-type C57/Bl6 mice, perfusion of NMDA (100 µm) induced a two-fold stimulation of ACh release. This effect was attenuated in mice lacking endothelial NOS but was completely absent in mice lacking neuronal NOS. Local perfusion of SIN-1 (300…
The effect of tacrine on acetylcholine overflow in the heart
1990
Tacrine, 10(-6) M, enhanced the acetylcholine (ACh) overflow evoked in perfused chicken hearts by field stimulation (5 Hz, 1 min) from 183 to 346 pmol g-1 min-1. Increase to the same level were observed after pretreatment with diisopropylfluorophosphate (DFP) as well as after DFP plus 10(-6) M tacrine. Tacrine, 10(-5) M, caused further enhancement with or without DFP up to 851 pmol g-1 min-1. It was concluded that 10(-6) M tacrine enhanced the ACh overflow by choline esterase inhibition, whereas 10(-5) M tacrine caused, in addition, an increase of neuronal ACh release.
Cigarette smoke extract activates human bronchial epithelial cells affecting non-neuronal cholinergic system signalling in vitro.
2010
Abstract Aims Acetylcholine (ACh) is synthesized by Choline Acetyl-Transferase (ChAT) that exerts its physiological effects in airway epithelial cells via muscarinic receptor (MR) activation. We evaluate the effect of ACh stimulation on human bronchial epithelial cells (16-HBE) and test whether cigarette smoke extract (CSE) can modify the basal cellular response to ACh affecting the non-neuronal cholinergic system signalling. Main methods ACh stimulated 16-HBE were tested for ACh-binding, Leukotriene B 4 (LTB 4 ) release and ERK1/2 and NFkB pathway activation. Additionally, we investigated all the aforementioned parameters as well as ChAT and MR proteins and mRNA expression and endogenous A…
Refractory Death Rattle: Deep Aspiration Facilitates the Effects of Antisecretory Agents
2011
Anticholinergic drugs, including atropine, hyoscine butylbromide, and scopolamine, have been shown to be equally effective in the treatment of death rattle. However, anticholinergic drugs may only be effective in reducing the production of further secretions, rather than eliminating the existing ones. A case is described in which a preventive procedure was undertaken to carefully eliminate secretions before starting anticholinergic drugs. Airway aspiration under light anesthesia removed secretions before starting anticholinergic drugs. Low doses of propofol were given intravenously to make a laryngoscopy feasible, allowing the complete aspiration of large amounts of tracheal secretions. No …
Glucose plus choline improve passive avoidance behaviour and increase hippocampal acetylcholine release in mice.
2001
The present study tests the effects of glucose and choline, the biosynthetic precursors of acetylcholine, on passive avoidance behaviour and hippocampal acetylcholine release measured by microdialysis in awake mice. Glucose (10 and 30mg/kg) or choline chloride (6-60mg/kg), given by i.p. injection immediately after training, dose-dependently enhanced retention in an inhibitory avoidance task. Combinations of low doses of glucose (10mg/kg) and choline chloride (20mg/kg) which alone were submaximally effective significantly increased retention latencies in a synergistic manner, an effect which was sensitive to atropine (0.5mg/kg). This beneficial effect vanished when higher doses of glucose or…
Intestinal ischaemia during cardiac arrest and resuscitation: comparative analysis of extracellular metabolites by microdialysis.
2003
Intestinal ischaemia is a major complication of shock syndromes causing translocation of bacteria and endotoxins and multiple organ failure in intensive care patients. The present study was designed to use microdialysis as a tool to monitor intestinal ischaemia after cardiac arrest and resuscitation in pigs. For this purpose, microdialysis probes were implanted in pig jejunal wall, peritoneum, skeletal muscle and brain, and interstitial fluid was obtained during circulatory arrest (induced by ventricular fibrillation) and after return of spontaneous circulation (ROSC). Cardiac arrest for 4 min caused a prolonged (60 min) reduction of blood flow in jejunal wall, muscle and brain as determine…
Serotonergic modulation of hippocampal acetylcholine release after long-term neuronal grafting
2000
Adult female rats sustained aspirative fimbria-fornix lesions and, 2 weeks later, received intrahippocampal grafts of fetal septal or mixed septal-raphe cell suspensions. Twenty-four months later, the extracellular concentration of hippocampal acetylcholine (ACh) was determined by microdialysis. Basal ACh levels (5-65 fmol/5 microl sham-operated rats) were strongly reduced after lesioning (3-7 fmol/5 microl). In septally transplanted and septal-raphe co-transplanted rats, hippocampal ACh concentrations were restored to near-normal levels (15-25 fmol/5 microl), indicating long-term functional survival of hippocampal transplants. After administration of citalopram (100 microM by infusion) and…