Journal: Advanced Science

Article Title: Human Foetal Neuroblasts Exhibit BK Channel‐Dependent Membrane Voltage Oscillations upon Depolarization

doi: 10.1002/advs.76767

Figure Lengend Snippet: Voltage waves in hf NBMNs are blocked by the selective big‐conductance Ca 2+ ‐activated K + (BK) channel blocker iberiotoxin (IbTx). (A) The frequency (left y axis: in bins) and amplitude (right y axis: in dots) of voltage waves evoked by a current step of 500 pA (500 ms duration) are expressed as a function of time in a representative hf NBM exposed to different compounds: IbTx (200 n m ); ZD7288 (ZD; 50 µ m ) or TEA (0.2 m m ). Letters in the graph (a, b, c) represent specific time points where original voltage traces are compared. (B) Original voltage traces recorded in the same cell at specific time points: before (a: black trace), during (b: red trace), or after (c: blue trace) the application of 200 n m IbTx, a selective BK channel blocker. The dotted line indicates the 0 mV level. Scale bars: 200 ms; 100 mV. Upper panel: magnification of original voltage traces. (C) Representative image of immunofluorescence analysis demonstrating that hf NBMNs express KCNMA1 (KCa1.1: α subunit of BK channels: in red; NeuN in green). The adjacent negative control panel shows the red and green channels acquired after omission of the primary antibodies. Scale bar: 20 µm. (D–K) Averaged time courses (mean ± SE) of wave parameters (frequency, amplitude, integral and half width) measured in 4 hf NBMNs exposed to 200 n m IbTx (D–G) or in 4 hf NBMNs exposed to 0.2 m m TEA (H–K).

Article Snippet: Iberiotoxin (IbTX) was purchased from Alomone Labs (Jerusalem, Israel).

Techniques: Immunofluorescence, Analysis, Negative Control, Patch Clamp

Journal: The FASEB Journal

Article Title: Orchestration of PKC ‐Mediated Inhibition and Calcium Release‐Mediated Activation of BK Currents in Rat Vascular Smooth Muscle Cells by Melatonin Confers a BK ‐Channel‐Dependent Restraint on Melatonin‐Induced Vasocontraction

doi: 10.1096/fj.202601214R

Figure Lengend Snippet: Melatonin stimulates outward currents. (A) time course of the outward current at a test potential of +70 mV during the addition of 10 −5 mol l −1 melatonin (Mel), of bath solution (time control) and of 10 −5 mol l −1 melatonin in the presence of 3*10 −7 mol l −1 iberiotoxin, a specific BK channel inhibitor (Mel + IBTX). The application period of melatonin and of the bath solution, respectively, is indicated by the gray area; s—start of application, e—end of application; data points are the mean current during the last 200 ms of the voltage step. (B) Example traces of the outward current at the start (s) and the end (e) of melatonin application evoked by a voltage step from a holding potential of −40 mV to a test potential of +70 mV with duration 500 ms (left panel) and a voltage ramp from −70 mV to +100 mV providing the I‐V relationship (right panel), respectively. (C) Summarized data of the effect of melatonin (Mel) on the outward current, data are expressed as the ratio of the current at the end of the application period (I K (e)) to the initial current immediately at the start of the application period (I K (s)); test potential +70 mV; number of cells investigated appears on bar; * ‐ p < 0.05.

Article Snippet: Iberiotoxin was obtained from Alomone.

Techniques: Control

Journal: Scientific Reports

Article Title: Tectorigenin induces vasorelaxation in porcine coronary arteries through activation of Kv channels and oestrogen receptor modulation

doi: 10.1038/s41598-025-20988-6

Figure Lengend Snippet: Involvement of potassium channels in tectorigenin-induced vasorelaxation in porcine coronary arteries. ( A ) Effects of various potassium channel blockers on vasorelaxation induced by 30 µM tectorigenin. Pretreatment with glibenclamide (10 µM), iberiotoxin (IbTX, 200 nM), tetraethylammonium (TEA, 1 mM), apamin (100 nM), or charybdotoxin (1 µM) did not significantly affect the relaxant response ( p > 0.05), whereas 4-aminopyridine (4-AP, 1 mM) significantly attenuated tectorigenin-induced relaxation ( p < 0.05). ( B ) Concentration-dependent inhibitory effect of 4-AP (1 mM) on tectorigenin-induced relaxation. Significant inhibition was observed at 10 and 30 µM († p < 0.05 vs. corresponding tectorigenin alone), but not at 100 µM. ( C ) Comparison of the relaxant effects of 30 µM tectorigenin in porcine coronary arteries pre-contracted with either 100 nM U46619 or 80 mM KCl. Tectorigenin elicited significant vasorelaxation in U46619-pre-contracted rings but had negligible effect in KCl-contracted rings. Data are expressed as mean ± standard error of the mean (SEM) from four independent hearts. U46619 plateau (normalised to 60 mM KCl) was similar across groups ( p > 0.05; Supplementary Table 2).

Article Snippet: For experimental assays, a range of pharmacological agents was utilised, including U46619, apamin, KT5720, KT5823, and L-NNA (Sigma-Aldrich, MO, USA); rolipram, vardenafil, and TEA (Santa Cruz Biotechnology, CA, USA); IbTX (Alomone Labs, Jerusalem, Israel); glibenclamide (Research Biochemicals International, MA, USA); TTX and 4-AP (Tocris Bioscience, Bristol, UK); CTX (Bachem, Bubendorf, Switzerland); and charybdotoxin, methyl-piperidino-pyrazole (MPP), and PHTPP (Cayman Chemical, MI, USA).

Techniques: Concentration Assay, Inhibition, Comparison