Clofilium phosphate
Clofilium phosphate (LY 150378) is an antiarrhythmic/antifibrillatory agent. Clofilium phosphate significantly prolongs the action potential duration and effective refractory period of canine cardiac Purkinje fibers, increases the ventricular fibrillation threshold, reduces the risk of reentrant arrhythmias, and enables spontaneous conversion of some ventricular fibrillation episodes to sinus rhythm. Clofilium phosphate is applicable to research related to ventricular fibrillation, arrhythmias, and ventricular tachyarrhythmias.
For research use only. We do not sell to patients.
- CAS No.: 68379-03-3
- Formula: C21H39ClNO4P
- Molecular Weight:435.97
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Storage:
Please store the product under the recommended conditions in the Certificate of Analysis.
Biological Activity
Description
In Vitro
Clofilium phosphate selectively prolongs the action potential duration and effective refractory period of Purkinje fibers in normal dogs[1].
Clofilium phosphate (30-100 nM) prolongs the action potential duration of canine papillary muscle and ventricular free wall cells, but exerts no effect on the APD of atrial muscle at the tested concentrations[1].
Clofilium phosphate (30-1000 nM; for at least 1 h) selectively prolongs the action potential duration and refractory period of isolated normal canine Purkinje fibers, without significantly altering membrane responsiveness, conduction velocity, or diastolic depolarization rate; its APD-prolonging effect is more pronounced under conditions of longer basic cycle lengths and in depolarized fibers at higher concentrations[2].
Clofilium phosphate (0.01-10 μM; 30 min) potently prolongs the APD95 of isolated canine cardiac Purkinje fibers, with a C20APD95 value of 0.26 μM, and produces a maximum 39 ± 8% increase in APD95 at 10 μM[3].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only. Further protocols information, click here.
In Vivo
Clofilium phosphate (10 mg/kg; intradermal injection) prolongs the left ventricular functional refractory period of anesthetized healthy mongrel dogs by at least 12%[3].
Clofilium phosphate (0.1-10 mg/kg; intravenous injection) prevents programmed electrical stimulation-induced ventricular tachycardia in 70% of anesthetized mongrel dogs with 24-hour-old myocardial infarction[3].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
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Animal Model:mongrel (adult, 8-15 kg, pentobarbital-anesthetized, electrical stimulation-induced ventricular fibrillation model)[1]
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Dosage:0.5 µmole/kg; 1.0 µmole/kg
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Administration:i.v.; infused over 30 minutes
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Result:Increased mean ventricular fibrillation threshold (VFT) by 98% from pre-drug values at 0.5 µmole/kg.
Induced spontaneous conversion of ventricular fibrillation (VF) to normal sinus rhythm in 8% of episodes (2 out of 25), with VF lasting an average of 8.5 seconds at 0.5 µmole/kg.
Increased mean VFT by 205% from pre-drug values at 1.0 µmole/kg, with this increase significant at all post-infusion time periods.
Induced spontaneous conversion of VF to normal sinus rhythm in 22% of episodes (5 out of 23), with VF lasting an average of 8.5 seconds at 1.0 µmole/kg.
Produced significantly higher VFT at the 4th post-infusion determination (≈240 minutes after end of infusion) than at the first three post-infusion determinations for both doses.
Chemical Information
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CAS No. 68379-03-3
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Molecular Weight 435.97
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Formula C21H39ClNO4P
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SMILES
O=P([O-])(O)O.ClC1=CC=C(C=C1)CCCC[N+](CC)(CC)CCCCCCC
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Synonyms
LY 150378
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Shipping
Room temperature in continental US; may vary elsewhere.
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Storage
Please store the product under the recommended conditions in the Certificate of Analysis.
Protocols
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Cardiac voltage-sensitive optical mapping
Cardiac voltage-sensitive optical mapping records changes in transmembrane potential from cardiac tissue by staining the preparation with a voltage-sensitive dye and imaging fluorescence changes during electrical activation; the resulting optical action potentials can be used to map activation time, action potential duration, conduction velocity, wavefront propagation, and arrhythmia dynamics. The optical signal represents a relative fluorescence change from a tissue volume rather than a single-cell intracellular recording, so spatial resolution, sampling rate, voltage resolution, optical magnification, light penetration, and motion control must be considered together when interpreting optical action potentials.
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Neuronal voltage-sensitive dye imaging
Neuronal voltage-sensitive dye imaging detects membrane-potential-dependent optical changes from dyes associated with neuronal membranes, enabling optical recording of electrical activity from single neurons, dendrites, axons, spines, or neuronal populations in brain slices and cultured neurons. VSD signals are typically reported as fractional fluorescence or absorbance changes over baseline, such as ΔF/F or ΔI/I, and published protocols use high-speed cameras or photodiode arrays because neuronal voltage signals occur on millisecond time scales. Fast VSD imaging can be applied at two common scales: bulk staining of brain slices to measure circuit-level spatiotemporal activity, and single-cell loading or biolistic delivery to record membrane-potential transients from individual neuronal compartments. Optical signals should be interpreted as membrane-potential-related readouts, and validation by simultaneous electrophysiology or pharmacological controls is recommended when the experimen
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Acute brain-slice whole-cell patch-clamp recording
Acute brain-slice whole-cell patch-clamp recording measures membrane voltage or ionic current from visually targeted cells in living brain slices; after giga-seal formation, the membrane under the pipette is ruptured to provide low-resistance electrical access to the cell interior, enabling current-clamp analysis of excitability and voltage-clamp analysis of synaptic or membrane currents. Acute slices preserve local tissue architecture better than dissociated preparations and allow visually guided recording from defined brain regions or fluorescently labeled cells; however, whole-cell access also permits exchange between pipette solution and cytoplasm, so intracellular dialysis must be considered when interpreting signaling-dependent phenomena.
Purity & Documentation
References
[2]. Steinberg MI, et al. Cellular electrophysiology of clofilium, a new antifibrillatory agent, in normal and ischemic canine Purkinje fibers. J Cardiovasc Pharmacol. 1981;3(4):881-895. [Content Brief]
[3]. Lis R, et al. Synthesis and antiarrhythmic activity of novel 3-alkyl-1-[omega-[4-[(alkylsulfonyl)amino]phenyl]-omega- hydroxyalkyl]-1H-imidazolium salts and related compounds. J Med Chem. 1987 Apr;30(4):696-704. [Content Brief]
Calculators
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)