Search results for "acetylcholine."

Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transfe…

2006

0048-3575 doi: DOI: 10.1016/j.pestbp.2005.05.002; Oral toxicity of boric acid, an inorganic insecticide, was evaluated on German cockroach, Blattella germanica L. (Dictyoptera, Blattellidae). Newly emerged adults were exposed to various concentrations of boric acid incorporated into the diet. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. Histological study of midgut revealed alterations in the epithelial cells and a signiWcant increase in the epithelium thickness. In a second series of experiments, the compound was investigated on the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs). Data showed that the compound…

The antioxidant 2,3‐dichloro,5,8‐dihydroxy,1,4‐naphthoquinone inhibits acetyl‐cholinesterase activity and amyloid β 42 aggregation: A dual target the…

2020

Alzheimer's disease is characterized by amyloid β aggregation and cholinergic neurodegeneration. In the present study, pure DDN (2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone) was examined, for the first time, for its dual potential as inhibitor of acetylcholinesterase (AChE) and Aβ42 aggregation. Such investigation was encouraged by the in vitro high antioxidant potential of DDN. Indeed, it revealed interesting antioxidant activity with IC50 values of 9.8 and 4.3 µM for ABTS and reducing power, respectively. The ability of DDN to counteract Aβ42 aggregation was evaluated by thioflavine-T assay. Strong inhibition of Aβ42 aggregation of more than 90% at 25 µM was measured. Moreover, results …

Are mussels able to distinguish underwater sounds? Assessment of the reactions of Mytilus galloprovincialis after exposure to lab-generated acoustic …

2016

This study examined the effects of lab-generated acoustic signals on the behaviour and biochemistry of Mediterranean mussels (Mytilus galloprovincialis). The experiment was carried out in a tank equipped with a video-recording system using six groups of five mussels exposed to five acoustic treatments (each treatment was replicated three times) for 30 min. The acoustic signals, with a maximum sound pressure level of 150 dB rms re 1 μPa, differed in frequency range as follows: low (0.1–5 kHz), mid-low (5–10 kHz), mid (10–20 kHz), mid-high (20–40 kHz) and high (40–60 kHz). The exposure to sweeps did not produce any significant changes in the mussels' behaviour. Conversely, the specimens expos…

Antioxidant activity and enzymes inhibitory properties of several extracts from two Moroccan Asteraceae species

2018

Abstract The present work reports investigation on phenolic compounds, antioxidant activity and enzyme inhibitory activities (acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-amylase and α-glucosidase) of different extracts from two Moroccan Asteraceae species; Bubonium imbricatum Cav. and Cladanthus arabicus (L.) Cass. B. imbricatum extracts contained the highest amounts of phenolics and flavonoids, and also exhibited higher antioxidant activity. In this species, the highest total phenolic (1611.13 ± 14.23 μmolGAE/gextract) and flavonoid (376.11 ± 8.22 μmolQE/gextract) contents were observed in aqueous-methanol extract obtained by maceration. Further, UHPLC–MS analysis of C. arab…

2019

The P-STS human ileal neuroendocrine tumor cells, as a model for gut enterochromaffin cells, are strongly and synergistically activated by histamine plus acetylcholine (ACh), presumably via histamine 4 receptors, and weakly activated by histamine alone. Sensing these signals, enterochromaffin cells could participate in intestinal intolerance or allergic reactions to food constituents associated with elevated histamine levels. In this study we aimed to analyze the underlying molecular mechanisms. Inhibition by mepyramine and mibefradil indicated that histamine alone caused a rise in intracellular calcium concentration ([Ca2+]i) via histamine 1 receptors involving T-type voltage-gated calciu…

Muscarinic type-1 receptors contribute to I-K,I-ACh in human atrial cardiomyocytes and are upregulated in patients with chronic atrial fibrillation

2018

Background: Basal and acetylcholine-gated inward-rectifier K+-currents (I-K1 and I-K,I-ACh, respectively) are altered in atrial fibrillation (AF). G(i)-protein-coupled muscarinic (M) receptors type-2 are considered the predominant receptors activating I-K,I-ACh. Although a role for G(q)-coupled non-M-2-receptor subtypes has been suggested, the precise regulation of I-K,I-ACh by multiple M-receptor subtypes in the human atrium is unknown. Here, we investigated M-1-receptor-mediated I-K,I-ACh regulation and its remodeling in chronic AF (cAF). Methods and results: M-1-receptor mRNA and protein abundance were increased in atrial cardiomyocyte fractions and atrial homogenates from cAF patients, …

Heat shock protein (Hsp) regulation by muscarinic acetylcholine receptor (mAChR) activation in the rat hippocampus.

2018

The cholinergic system plays a crucial role in modulating in the central nervous system physiological responses such as neurogenesis, neuronal differentiation, synaptic plasticity, and neuroprotection. In a recent study, we showed that Oxotremorine-M, a non-selective muscarinic acetylcholine receptor agonist, is able to transactivate the fibroblast growth factor receptor and to produce a significant increase in the hippocampal primary neurite outgrowth. In the present study we aimed to explore in the rat hippocampus the possible effect of acute or chronic treatment with Oxotremorine-M on some heat shock proteins (Hsp60, Hsp70, Hsp90) and on activation of related transcription factor heat sh…

Do β3-adrenoceptor agonists cause urinary bladder smooth muscle relaxation by inhibiting acetylcholine release?

2017

The mechanisms leading to improvement of overactive bladder syndrome upon treatment with a β3-adrenoceptor agonist remain controversial. New research points to a role of inhibition of neuronal acetylcholine release. Whether this occurs by a direct effect on prejunctional β3-adrenoceptors or indirectly by formation of adenosine and activation of A1 adenosine receptors is being discussed.

Dopamine induces inhibitory effects on the circular muscle contractility of mouse distal colon via D1- and D2-like receptors

2016

Dopamine (DA) acts as gut motility modulator, via D1- and D2-like receptors, but its effective role is far from being clear. Since alterations of the dopaminergic system could lead to gastrointestinal dysfunctions, a characterization of the enteric dopaminergic system is mandatory. In this study, we investigated the role of DA and D1- and D2-like receptors in the contractility of the circular muscle of mouse distal colon by organ-bath technique. DA caused relaxation in carbachol-precontracted circular muscle strips, sensitive to domperidone, D2-like receptor antagonist, and mimicked by bromocriptine, D2-like receptor agonist. 7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benz…

Altered gastrointestinal motility in an animal model of Lesch-Nyhan disease.

2018

Mutations in the HGPRT1 gene, which encodes hypoxanthine-guanine phosphoribosyltransferase (HGprt), housekeeping enzyme responsible for recycling purines, lead to Lesch-Nyhan disease (LND). Clinical expression of LND indicates that HGprt deficiency has adverse effects on gastrointestinal motility. Therefore, we aimed to evaluate intestinal motility in HGprt knockout mice (HGprt(−)). Spontaneous and neurally evoked mechanical activity was recorded in vitro as changes in isometric tension in circular muscle strips of distal colon. HGprt(−) tissues showed a lower in amplitude spontaneous activity and atropine-sensitivity neural contraction compared to control mice. The responses to carbachol a…