Search results for "Carbachol"
showing 10 items of 54 documents
Functional nicotinic acetylcholine receptors on subplate neurons in neonatal rat somatosensory cortex.
2004
The establishment of cortical synaptic circuits during early development requires the presence of subplate neurons (SPn's), a heterogeneous population of neurons capable to integrate and process synaptic information from the thalamus, cortical plate, and neighboring SPn's. An accumulation of cholinergic afferents and nicotinic acetylcholine receptors (nAChRs) has been documentated in the subplate around birth. To assess the developmental role of the cholinergic innervation onto SPn's, we used whole cell patch-clamp recordings of visually identified and biocytin-labeled SPn's in neonatal rat somatosensory cortex. Functional nAChRs were present in 92% of the investigated SPn's. Activation of…
Validation of Fenoterol to Study β<sub>2</sub>-Adrenoceptor Function in the Rat Urinary Bladder
2021
Fenoterol is a β<sub>2</sub>-adrenoceptor (AR)-selective agonist that is commonly used to investigate relaxation responses mediated by β<sub>2</sub>-AR in smooth muscle preparations. Some data have questioned this because fenoterol had low potency in the rat urinary bladder when a muscarinic agonist was used as a pre-contraction agent and because some investigators proposed that fenoterol may act in part via β<sub>3</sub>-AR. We designed the present study to investigate whether fenoterol is a proper pharmacological tool to study β<sub>2</sub>-AR-mediated relaxation responses in the rat urinary bladder. Firstly, we have compared the effect of p…
Failure of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) to inhibit soluble guanylyl cyclase in rat ventricular cardiomyocytes
1999
The effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylyl cyclase (sGC), were investigated in aortic rings and ventricular cardiomyocytes from rats. The production of cyclic GMP was stimulated by NO•-donors or carbachol. Additionally, the effects of ODQ were studied in cytosolic extracts from both tissues in which the cyclic GMP production was stimulated by S-nitroso-N-acetylpenicillamine (SNAP). In endothelium-intact aortic rings, SNAP (100 μM), 2,2′-(hydroxynitrosohydrazino)bis-ethanamine (DETA NONOate; 100 μM), or carbachol (10 μM) increased cyclic GMP levels about 4 fold. These effects were abolished by ODQ (50 μM). In cardiomyocytes, SNAP (100 μ…
Aclidinium inhibits cholinergic and tobacco smoke-induced MUC5AC in human airways.
2010
Mucus hypersecretion and mucin MUC5AC overexpression are pathological features of chronic obstructive pulmonary disease (COPD). This study examines the inhibitory effect of aclidinium, a new long-acting muscarinic antagonist, on MUC5AC expression in human airway epithelial cells. MUC5AC mRNA (RT-PCR) and protein expression (ELISA and immunohistochemistry) were studied in human bronchial tissue and differentiated human airway epithelial cells activated with carbachol (100 μM) or cigarette smoke extract in the absence or presence of aclidinium. Carbachol increased MUC5AC mRNA and protein expression in human bronchus and cultured epithelial cells. Aclidinium inhibited the carbachol-induced MUC…
Aclidinium inhibits human lung fibroblast to myofibroblast transition
2011
Background Fibroblast to myofibroblast transition is believed to contribute to airway remodelling in lung diseases such as asthma and chronic obstructive pulmonary disease. This study examines the role of aclidinium, a new long-acting muscarinic antagonist, on human fibroblast to myofibroblast transition. Methods Human bronchial fibroblasts were stimulated with carbachol (10 −8 to 10 −5 M) or transforming growth factor-β1 (TGF-β1; 2 ng/ml) in the presence or absence of aclidinium (10 −9 to 10 −7 M) or different drug modulators for 48 h. Characterisation of myofibroblasts was performed by analysis of collagen type I and α-smooth muscle actin (α-SMA) mRNA and protein expression as well as α…
Inhibition of FcεRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase)
1996
Abstract Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation…
Peripheral motor action of glucagon-like peptide-1 through enteric neuronal receptors
2010
Background Glucagon-like peptide-1 (GLP-1) is a proglucagon-derived peptide expressed in the enteroendocrine-L cells of small and large intestine and released in response to meal ingestion. Glucagon-like peptide-1 exerts inhibitory effects on gastrointestinal motility through vagal afferents and central nervous mechanisms; however, no data is available about a direct influence on the gastrointestinal wall. Our aim was to investigate the effects of GLP-1 on the spontaneous and evoked mechanical activity of mouse duodenum and colon and to identify the presence and distribution of GLP-1 receptors (GLP-1R) in the muscle coat. Methods Organ bath recording technique and immunohistochemistry wer…
Stimulation with carbachol alters endomembrane distribution and plasma membrane expression of intracellular proteins in lacrimal acinar cells.
2000
The events that lead to Sjogren's autoimmune processes in the lacrimal gland remain poorly understood. The acinar cell's responses to acute cholinergic stimulation include release of secretory products across the apical plasma membrane (apm) and a number of processes related to traffic between endomembrane compartments and the basal-lateral plasma membranes (blm), such as recruitment of Na, K-ATPase, accelerated recycling, and accelerated transcytosis of secretory IgA. We tested the hypothesis that stimulation-induced acceleration of endomembrane traffic is accompanied by changes in compartmentation and increased blm expression of proteins that are normally sequestered in endomembrane compa…
Mucosa-dependent muscarinic liberation of prostaglandins from rat isolated trachea.
1995
1. The present study examined whether cholinoceptor stimulation modulates the release of arachidonic acid-derived mediators from rat isolate tracheae. 2. Tracheae were preincubated with [3H]-arachidonic acid and the outflow of 3H-compounds was determined. Acetylcholine and the muscarinic agonist, carbachol but not nicotine, increased the rate of tritium outflow maximally by about 30%. The M3 receptor-preferring antagonist rho-fluoro-hexahydrosiladiphenidol was more effective than pirenzepine and methoctramine in antagonizing the effect of acetylcholine. 3. High performance liquid chromatography analysis (methanol gradient) of the released 3H-compounds showed that one peak, co-eluting with […
Antagonism by SR 48692 of mechanical responses to neurotensin in rat intestine.
1996
Abstract 1. The effects of SR 48692 on neurotensin (NT)-induced mechanical responses were investigated in rat duodenum and proximal colon by use of isometric, isovolumic preparations. 2. SR 48692 inhibited the relaxant responses to NT in duodenal circular and longitudinal muscle. It also antagonized the NT-induced contractile effects in duodenal circular muscle and in proximal colon (both muscular layers). 3. From Schild analysis and pA2 value for SR 48692 was 8.2 in tissues where NT induced relaxant effects and 7.5 in tissues where NT induced contractile effects and the slope of the regression line was not significantly different from unity, indicating competitive antagonism. 4. SR 48692 d…