atx  (Alomone Labs)

Journal: The Journal of General Physiology

Article Title: Tetrodotoxin-sensitive Navs contribute to early and delayed afterdepolarizations in long QT arrhythmia models

doi: 10.1085/jgp.201711909

Figure Lengend Snippet: nNa v inhibition reduces LQT-associated VT. (a) Representative ECG recordings in CASQ-null mice after catecholamine challenge (black ECG) composed of epinephrine (1.5 mg/kg) and caffeine (120 mg/kg) injected intraperitoneally, which induced a narrow-QRS complex VT exhibiting beat-to-beat alternations in the polarity of QRS. Addition of BayK (1 mg/kg; orange ECG) or ATX-II (30 µg/kg; red ECG) resulted in a typical short-long-short initiating ventricular cycle leading to a wide-QRS complex polymorphic VT that resembled human TdP. A subset of mice 10 min after exposure to BayK or ATX-II and 10 min before catecholamine challenge were pretreated with either 4,9-ah-TTX (750 µg/kg; blue ECGs) or riluzole (Ril; 15 mg/kg). (b) VT incidence (%) in CASQ-null mice exposed to catecholamine challenge without (black bars) and with BayK (orange bars) or ATX-II (red bars) during Na + channel blockade with 4,9-ah-TTX or Ril (green bars). Number of mice from independent experiments is specified in the bar graph. VT was defined as three or more premature ectopies. (c) TdP-like VT incidence (%) in CASQ-null mice exposed to catecholamine challenge without (black bars) and with BayK (orange bars) or ATX-II (red bars) during Na + channel blockade with 4,9-ah-TTX or Ril (green bars). TdP-like VT was defined as three or more premature wide-QRS ectopies. Significance between the treatment groups was determined with Fisher’s exact test.

Article Snippet: Briefly, after baseline recording (5 min), a subset of animals received either intraperitoneal ATX-II (30 µg/kg; Alomone Labs) or BayK (1 mg/kg; Tocris).

Techniques: Inhibition, Mouse Assay, Injection

Journal: The Journal of General Physiology

Article Title: Tetrodotoxin-sensitive Navs contribute to early and delayed afterdepolarizations in long QT arrhythmia models

doi: 10.1085/jgp.201711909

Figure Lengend Snippet: nNa v inhibition reduces LQT-associated VT. (a) Representative ECG recordings in CASQ-null mice after catecholamine challenge (black ECG) composed of epinephrine (1.5 mg/kg) and caffeine (120 mg/kg) injected intraperitoneally, which induced a narrow-QRS complex VT exhibiting beat-to-beat alternations in the polarity of QRS. Addition of BayK (1 mg/kg; orange ECG) or ATX-II (30 µg/kg; red ECG) resulted in a typical short-long-short initiating ventricular cycle leading to a wide-QRS complex polymorphic VT that resembled human TdP. A subset of mice 10 min after exposure to BayK or ATX-II and 10 min before catecholamine challenge were pretreated with either 4,9-ah-TTX (750 µg/kg; blue ECGs) or riluzole (Ril; 15 mg/kg). (b) VT incidence (%) in CASQ-null mice exposed to catecholamine challenge without (black bars) and with BayK (orange bars) or ATX-II (red bars) during Na + channel blockade with 4,9-ah-TTX or Ril (green bars). Number of mice from independent experiments is specified in the bar graph. VT was defined as three or more premature ectopies. (c) TdP-like VT incidence (%) in CASQ-null mice exposed to catecholamine challenge without (black bars) and with BayK (orange bars) or ATX-II (red bars) during Na + channel blockade with 4,9-ah-TTX or Ril (green bars). TdP-like VT was defined as three or more premature wide-QRS ectopies. Significance between the treatment groups was determined with Fisher’s exact test.

Article Snippet: Briefly, after baseline recording (5 min), a subset of animals received either intraperitoneal ATX-II (30 µg/kg; Alomone Labs) or BayK (1 mg/kg; Tocris).

Techniques: Inhibition, Mouse Assay, Injection

Journal: Scientific Reports

Article Title: Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions

doi: 10.1038/s41598-017-01056-0

Figure Lengend Snippet: Reduction of MAPD 90 prolongation by Tetrodotoxin (TTX) and eleclazine (Elec) in hearts treated with Bay K 8644 alone and ATX-II plus Bay K 8644. ( a ) Representative recordings of MAPs recorded from the epicardium of the left ventricular wall in serially exposed to no drug (control, curve 1), ATX-II (3 nM, curve 2), ATX-II plus Bay K 8644 (200 nM, curve 3), ATX-II plus Bay K 8644 plus TTX (1 µM, curve 4), and ATX-II plus Bay K 8644 plus eleclazine (10 µM, curve 5). ( b ) Concentration-dependent decreases by TTX of epi-MAPD 90 and endo-MAPD 90 in the presence of 300 nM Bay K 8644 (n = 7). ( c ) Effect of TTX (1 µM) and eleclazine (10 µM) on the increase of Δ epi-MAPD 90 and Δ endo-epi MAPD 90 induced by Bay K 8644 in absence and presence of ATX-II. * P

Article Snippet: To test the effects of Bay K 8644 in the presence of ATX-II (Alomone labs, Cat# STA-700, USA), hearts were perfused with ATX-II for 20 min and then exposed to Bay K 8644 and TTX.

Techniques: Concentration Assay

Journal: Scientific Reports

Article Title: Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions

doi: 10.1038/s41598-017-01056-0

Figure Lengend Snippet: TTX (at concentration of 1 µM) reduced the phosphorylation of CaMK II-δ and Na v 1.5 in hearts pretreated with Bay K 8644 (200 nM) in both absence and presence of ATX-II (3 nM). ( a ) Representative protein expression of p-CaMK II-δ, CaMK II-δ, p-Na v 1.5 and Na v 1.5 in rabbit left ventricular myocardium under conditions indicated. ( b ) and ( c ) The quantitative analysis of p-CaMK II-δ ( b ) and p-Na v 1.5 ( c ) protein expression. The corresponding intensity was normalized to expression in Ctrl. * P

Article Snippet: To test the effects of Bay K 8644 in the presence of ATX-II (Alomone labs, Cat# STA-700, USA), hearts were perfused with ATX-II for 20 min and then exposed to Bay K 8644 and TTX.

Techniques: Concentration Assay, Expressing

Journal: Scientific Reports

Article Title: Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions

doi: 10.1038/s41598-017-01056-0

Figure Lengend Snippet: TTX and eleclazine (Elec) abolished ventricular arrhythmias induced by Bay K 8644 both in absence ( a ) and presence ( b ) of ATX-II. Representative recordings of MAPs (upper records in each panel) and ECG (lower records in each panel) were recorded simultaneously in control, Bay K 8644 (200 and 300 nM, a ) or ATX-II-treated hearts ( b ) before and after treatment with TTX. Arrows indicate an episode of VT. The incidence of all ventricular arrhythmias and VT are presented in panel c. * P

Article Snippet: To test the effects of Bay K 8644 in the presence of ATX-II (Alomone labs, Cat# STA-700, USA), hearts were perfused with ATX-II for 20 min and then exposed to Bay K 8644 and TTX.

Techniques:

Journal: Scientific Reports

Article Title: Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions

doi: 10.1038/s41598-017-01056-0

Figure Lengend Snippet: Prolongation of left ventricular monophasic action potential duration (MAPD 90 ) by Bay K 8644 in the absence and presence of ATX-II. ( a ) and ( b ) Representative recordings of MAPs recorded from the epi- ( a ) and endo- ( b ) myocardium of the left ventricular wall in serially exposed to no drug (control), ATX-II (3 nM), Bay K 8644 (200 nM), and ATX-II (3 nM) plus Bay K 8644 (200 nM). ( c ) and ( d ) Concentration-dependent increases by Bay K 8644 of left ventricular epi- ( c ) and endo- ( d ) MAPD 90 in absence (n = 11) and presence (n = 7) of ATX-II. * P

Article Snippet: To test the effects of Bay K 8644 in the presence of ATX-II (Alomone labs, Cat# STA-700, USA), hearts were perfused with ATX-II for 20 min and then exposed to Bay K 8644 and TTX.

Techniques: Concentration Assay