Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Summary of the effects of different solutions, charybdotoxin and apical Ba2+ on CCh responses

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques:

Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Inhibition of forskolin-induced ISC increases by K+ channel blockade and the subsequent effects on CCh stimulation. (A) illustrates the effect on 10 μM forskolin responses of 10 min pretreatment with basolateral charybdotoxin (ChT, 100 nM), 293B (10 μM) or Ba2+ (1–10 mM). (B) shows the responses to 10 μM CCh added 30 min after forskolin in the same experiments, with each bar representing the 10 s spike (charybdotoxin treated cells only), 30 s spike and 2 min peak. The total number of observations or the frequency of individual components are indicated in round and square brackets respectively; **P<0.01 and ***P<0.001 compared to controls.

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques: Inhibition

Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Forskolin and CCh responses in the presence of charybdotoxin or Ba2+. Example experiments from Colony 1 epithelia in HCO3− free buffer show the effect of 10 min pretreatment with either 50 nM charybdotoxin (ChT) or 1 mM Ba2+ compared to untreated cells (upper trace). Agents were added at the following concentrations: forskolin (10 μM; For), CCh (10 μM) and piretanide (200 μM; Pir). Initial ISC levels are indicated on the left (in μA) of each representative trace.

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques:

Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Alteration of CCh responses by charybdotoxin. Representative traces illustrate the CCh-induced changes in ISC from the basal levels indicated, in control cells in KH solution or in those incubated with basolateral (bl) or both apical (ap) and basolateral charybdotoxin (50 nM) for 10 min. To the right of each trace, the histograms show the size of the 10 s spike (open bars), 30 s spike (shaded bars) or the 2 min increase in ISC (solid bars). Significant differences between control values (n=14) and those in charybdotoxin-pretreated cells (both n=3) are indicated by *P<0.05 and **P<0.01.

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques: Incubation

Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Inhibition of CCh-stimulated changes in ISC by apical Ba2+ and charybdotoxin. The histogram shows the separate phases of 10 μM CCh responses in untreated cells in HCO3− free solution (control, n=9) or those exposed to 50 nM basolateral (bl) charybdotoxin (n=4), 5 mM apical (ap) Ba2+ (n=4) or both treatments (n=4) for 10 min. Note that the 10 s spike component of the control group was present in only 4 out of 9 observations, and that the 30 s spike was absent in charybdotoxin-treated cells. Significant differences are indicated as follows: *P<0.05 compared to control cells; #P<0.05 compared to pretreatment with charybdotoxin only.

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques: Inhibition

Journal:

Article Title: Modulation of chloride, potassium and bicarbonate transport by muscarinic receptors in a human adenocarcinoma cell line

doi: 10.1038/sj.bjp.0702270

Figure Lengend Snippet: Proposed model for epithelial K+ and Cl− secretion in Colony 1 epithelia. The diagram indicates the apical and basolateral membrane conductances that are at present sufficient to explain the observed changes in ISC after either carbachol or forskolin in HCO3− free buffer, and the effects on these responses of the range of K+ channel blockers tested. Elevation of cyclic AMP levels activates basolateral Ba2+- and 293B-sensitive K+ channels, creating a favourable electrochemical gradient for Cl− exit through an apical cyclic AMP-gated Cl− conductance. Na+ ions, which enter via the Na+/K+/2Cl− cotransporter inhibited by piretanide (Piret), recycle across the basolateral membrane through the Na+/K+ ATPase. Ca2+-mediated agonists increase electrogenic Cl− secretion by opening a separate basolateral K+ conductance inhibited by charybdotoxin (ChT), but also activate a population of apical K+ channels that may at least be partially sensitive to Ba2+, allowing electrogenic K+ secretion. The existence of these apical channels underlies the distinctive biphasic responses to carbachol that are observed after basolateral blockade by charybdotoxin. In Krebs solution, increases in both the cyclic AMP and Ca2+ ion concentration may also modulate bicarbonate transport (not shown), as described in the text.

Article Snippet: Other drugs were purchased from the following companies: forskolin, CCh, acetazolamide and atropine (Sigma, Poole, U.K.), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), p -fluoro hexahydro-sila-difenidol HCl ( p F-HHSiD), gallamine and pirenzepine (RBI, St. Albans, U.K.) and charybdotoxin (Alamone Labs, Jerusalem, Israel).

Techniques: Concentration Assay

Journal: The Journal of Neuroscience

Article Title: Phenotypic Alteration of a Human BK ( hSlo ) Channel by hSloβ Subunit Coexpression: Changes in Blocker Sensitivity, Activation/Relaxation and Inactivation Kinetics, and Protein Kinase A Modulation

doi: 10.1523/JNEUROSCI.16-15-04543.1996

Figure Lengend Snippet: IBTX and ChTX pharmacology. A, Application of the BK channel-blocking peptide IbTX to oocytes expressing hSlo or hSlo + hSloβ revealed that coexpression with the hSloβ subunit resulted in a nearly 10-fold decrease in the sensitivity to IbTX blockade;n = 5–10 oocytes/IbTX concentration. Maximal effect was defined as the effect produced by incubation in 100–250 nm IbTX; maximal levels of suppression did not differ significantly between hSlo and hSlo + hSloβ. B, Application of the peptidyl blocker ChTX did not reveal a significantly different profile of blockade forhSlo and hSlo + hSloβ. Maximal effect was defined as the response to 250–500 nmChTX, and maximal levels of effect did not differ betweenhSlo and hSlo + hSloβ.

Article Snippet: Iberiotoxin (IbTX) and charybdotoxin (ChTX) (Peptides International, Louisville, KY) were prepared as aqueous stocks and diluted in MBS before use; tetrandrine (Aldrich, Milwaukee, WI) was prepared as a stock solution in dimethylformamide or dimethylsulfoxide (DMSO) and likewise diluted in the appropriate solution just before use.

Techniques: Blocking Assay, Expressing, Concentration Assay, Produced, Incubation

Journal:

Article Title: Mechanisms of nitric oxide-independent relaxations induced by carbachol and acetylcholine in rat isolated renal arteries

doi: 10.1038/sj.bjp.0703408

Figure Lengend Snippet: Effects of various K+ channel blockers on carbachol-induced, L-NAME-resistant relaxations. The relaxations were significantly reduced by tetraethylammonium (TEA), charybdotoxin (ChTX) and iberiotoxin (IbTX), but were not affected by 4-aminopyridine (4-AP), apamin or glibenclamide (Glib). Relaxations are expressed as % reduction of 0.1 μM phenylephrine-induced tone. Data are means±s.e.mean (n=3–6).

Article Snippet: The following drugs were used: acetylcholine chloride (Sigma Chemical Co., St. Louis, MO, U.S.A.), 4-aminopyridine (4-AP, Sigma), apamin (Sigma), atropine sulphate (Sigma), carbachol (carbamylcholine chloride, Sigma), charybdotoxin (ChTX, Auspep, Melbourne, Australia), glibenclamide (Sigma), iberiotoxin (IbTX, Auspep), indomethacin (Merck Sharp & Dohme (Australia) Pty.

Techniques:

Journal:

Article Title: Mechanisms of nitric oxide-independent relaxations induced by carbachol and acetylcholine in rat isolated renal arteries

doi: 10.1038/sj.bjp.0703408

Figure Lengend Snippet: Effects of TEA, ChTX, IbTX, ouabain, miconazole and K+ on the EC50 and Rmax of L-NAME resistant relaxations induced by carbachol

Article Snippet: The following drugs were used: acetylcholine chloride (Sigma Chemical Co., St. Louis, MO, U.S.A.), 4-aminopyridine (4-AP, Sigma), apamin (Sigma), atropine sulphate (Sigma), carbachol (carbamylcholine chloride, Sigma), charybdotoxin (ChTX, Auspep, Melbourne, Australia), glibenclamide (Sigma), iberiotoxin (IbTX, Auspep), indomethacin (Merck Sharp & Dohme (Australia) Pty.

Techniques: