Search results for " ACE"
showing 10 items of 1883 documents
Use of atropine-treated Daphnia magna survival for detection of environmental contamination by acetylcholinesterase inhibitors.
2003
The toxicity of cholinesterase-inhibiting compounds (e.g., carbamates and organophosphates) is due to a decrease in acetylcholine metabolism, which results in a continuous stimulation of cholinergic receptors (muscarinic and nicotinic) that can be fatal. The goal of this study was to evaluate the protective effect of atropine (muscarinic receptor antagonist) against paraoxon-induced toxicity to Daphnia magna using its survival rate for the detection of environmental contamination by cholinesterase-inhibiting compounds. As expected, paraoxon was lethal to D. magna in a concentration-dependent manner. Noteworthy, the pretreatment of these organisms with atropine dramatically increased their s…
Muscarinic Modulation of Acetylcholine Release from the Myenteric Plexus of the Guinea Pig Small Intestine
1978
The concept of a local feedback regulation of neurotransmitter release has been most intensively studied in the adrenergic system (See Ref. 13 for review). The feedback hypothesis of noradrenaline release is based on the findings that α-adrenolytic drugs enhance, and α-adrenoceptor agonists reduce neuronal noradrenaline release. Relatively few systematic studies have been made on the influence of cholinolytic and cholinomimetic drugs on the release of ACh. Szerb and Somogyi (14) reported that the potent muscarinic agonist oxotremorine inhibited ACh output from cerebral cortical slices. Further, the muscarinic antagonists atropine and hyoscine have been found to facilitate the release of ACh…
Subtypes of muscarinic receptor on cholinergic nerves and atrial cells of chicken and guinea-pig hearts
1988
1. Electrically driven chicken and guinea-pig atria were used to investigate the negative inotropic effects of the muscarinic agonists methacholine and acetylcholine (ACh). The release of ACh from isolated hearts into the perfusate in response to (preganglionic) vagal or (pre- and postganglionic) field stimulation was bioassayed on the guinea-pig ileum or determined by labelling with [3H]-choline. 2. Concentration-response curves for the negative inotropic effect of methacholine were shifted to the right by pirenzepine in various concentrations (0.03 to 10 mumol l-1). The pA2 values were 7.76 in chicken atria and 6.53 in guinea-pig atria. Pirenzepine and atropine antagonized the negative in…
Receptor phosphorylation does not mediate cross talk between muscarinic M(3) and bradykinin B(2) receptors.
1999
This study examined cross talk between phospholipase C-coupled muscarinic M3and bradykinin B2receptors coexpressed in Chinese hamster ovary (CHO) cells. Agonists of either receptor enhanced phosphoinositide signaling (which rapidly desensitized) and caused protein kinase C (PKC)-independent, homologous receptor phosphorylation. Muscarinic M3but not bradykinin B2receptors were also phosphorylated after phorbol ester activation of PKC. Consistent with this, muscarinic M3receptors were phosphorylated in a PKC-dependent fashion after bradykinin B2receptor activation, but muscarinic M3receptor activation did not influence bradykinin B2receptor phosphorylation. Despite heterologous phosphorylatio…
The non-neuronal cholinergic system in peripheral blood cells: Effects of nicotinic and muscarinic receptor antagonists on phagocytosis, respiratory …
2007
Peripheral blood cells express the complete non-neuronal cholinergic system. For example synthesis of acetylcholine and nicotinic as well muscarinic receptors have been demonstrated in leucocytes isolated from human peripheral blood. In the present experiments mononuclear cells and granulocytes were isolated from the peripheral blood to investigate content and synthesis of acetylcholine as well as phenotypic functions like respiratory burst, phagocytosis and migration. Mononuclear cells (T-cells and monocytes) contained 0.36 pmol/10(6) cells acetylcholine, whereas acetylcholine content in granulocytes was 100-fold lower. Acetylcholine synthesis amounted to 23.2+/-4.7 nmol/mg protein/h and 2…
Absence of muscarinic modulation of vasopressin release from the isolated rat neurohypophysis
1975
1. Isolated rat neurohypophyses were incubated in Locke solution at 37°C and the vasopressin output into the medium determined by bioassay. 2. Potassium chloride 60 mM caused a 9-fold increase in the rate of vasopressin release that was abolished when calcium chloride was omitted from the Locke solution. 3. Acetylcholine 5.5×10−4 M neither alone nor in the presence of atropine 2.9×10−6 M changed the “resting” release of vasopressin. 4. Neither acetylcholine 5.5×10−4 M nor oxotremorine 10−4 and 3×10−4 M altered the vasopressin release evoked by potassium chloride 60 mM. 5. In contrast to the peripheral adrenergic nerve fibres, the secretory terminal fibres of the neurohypophysis do not appea…
Analysis of pesticides in fruits by pressurized liquid extraction and liquid chromatography-ion trap-triple stage mass spectrometry.
2005
A multi-residue method using pressurized liquid extraction (PLE) and liquid chromatography-quadrupole ion trap-triple stage mass spectrometry (LC-IT-MS(3)) has been developed for determining trace levels of pesticides in fruits. The selected pesticides can be distinguished in: benzimidazoles and azoles, organophosphorus, carbamates, neonicotinoids, and acaricides. PLE has been optimized to extract these pesticide residues from oranges and peaches by studying the effect of experimental variables on PLE efficiency. Samples were extracted at high temperature and pressure (75 degrees C and 1500psi) using ethyl acetate as extraction solvent and acidic alumina as drying agent. The recoveries obta…
The integrity of cholinergic basal forebrain neurons depends on expression of Nkx2-1
2011
The transcription factor Nkx2-1 belongs to the homeobox-encoding family of proteins that have essential functions in prenatal brain development. Nkx2-1 is required for the specification of cortical interneurons and several neuronal subtypes of the ventral forebrain. Moreover, this transcription factor is involved in migratory processes by regulating the expression of guidance molecules. Interestingly, Nkx2-1 expression was recently detected in the mouse brain at postnatal stages. Using two transgenic mouse lines that allow prenatal or postnatal cell type-specific deletion of Nkx2-1, we show that continuous expression of the transcription factor is essential for the maturation and maintenanc…
Lures for red palm weevil trapping systems: aggregation pheromone and synthetic kairomone
2015
[EN] BACKGROUNDThe optimisation of the lure is essential for the implementation of trapping systems to control insect pests. In this work, the response of the red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, to increasing emission rates of its aggregation pheromone (ferrugineol) and the efficacy of a convenient synthetic kairomone based on fermentation odours (ethyl acetate and ethanol) have been evaluated in different years and locations along the Mediterranean basin. RESULTSIn general, although capture data and emission had noticeable variability among locations, significantly fewer RPW were captured in pyramidal Picusan (R) traps with the lowest ferrugineol emission rates tested…
Evaluation of the bending behaviour of laminated glass beams via electronic speckle pattern interferometry
2017
The paper is devoted to the experimental analysis of the kinematical and mechanical behaviour of laminated glass beam structures. In particular, the utilized laminated glass specimens are composed of two glass layers bonded by a polymer layer constituted by Ethylene-vinyl acetate whose thickness has been nominally considered as constant for all the specimens. The experimental behaviour of the analyzed specimens is deduced by applying Electronic Speckle- Pattern Interferometry technique; actually, among optical methods this technique (handled by phase-stepping technique) is very effective to obtain a full-field displacement map and to numerically achieve the longitudinal strain. In particula…