Query String: TETRACAINE
- Electrophysiological Assay (EP) (In Vitro Assay) The following voltage clamp electrophysiology studies are performed on representative compounds using cells heterologously expressing Nav1.7 or Nav1.5 channels. cDNAsfor Nav1.7 (NM_002977) and Nav1.5 (AC137587) are stably expressed in Chinese Hamstr Ovary (CHO) cells and CHL (Chinese Hamster Lung) cells respectively. Sodium currents are measured in the whole-cell configuration using Syncropatch 384PE (Nanlon Technologies, Germany). 1NPC -384 chips with custom medium resistance and single hole mode are used. Internal solution consists of (in mM): 110 CsCl, 10 CsCl, 20 EGTA, and 10 Hepes (pH adjusted to 7.2); and external solution contains (in mM): 60 NMDG, 80 NaCl, 4 KCl, 1 MgCl2, 2 CaCl2), 2 D-Glucose monohydrate, 10 Hepes (pH adjusted to 7.4 with NaOH). After system flushing, testing compounds are dissolved in external solution containing 0.1% Pluronic F-127. The chip is moved into the measuring head and the instrument primes the chip with external and internal solutions. 10 ul cells are added to the chip from a cell hotel, and a negative pressure of +-50 mBar is applied to form a seal. Following treatment with seal enhancer solution and wash-off with external solution, negative pressure of +-250 mbar is applied for 1 second to achieve the whole-cell configuration, followed by three washing steps in external solution. 20 ul of compounds is added to 40 ul in each well (1:3 dilution of compounds), and after mixing, 20 ul is removed so the volume is retained at 40 ul. After approximately 13 minutes recordings, 20 ul/well of 2 uM TTX, or 333 uM Tetracaine (for Nav1.5) is added to achieve full block.
- Electrophysiology Assay 1) Pre-spotted compounds (in neat DMSO) into compound plates. Vehicle control (neat DMSO), the positive control (20 mM DMSO stock tetracaine, 125 μM final in assay) and test compounds were added to each well at 160× desired final concentration in neat DMSO. Final compound plate volume was 80 μL (80-fold intermediate dilution from 1 μL DMSO spot; 160-fold final dilution after transfer to cell plate). Final DMSO concentration for all wells in assay was 0.625%.2) Prepared Hexyl Dye Solution.3) Prepared cell plates. On the day of the assay, medium was aspirated and cells were washed three times with 100 μL of Bath1 Solution, maintaining 25 μL residual volume in each well.4) Dispensed 25 μL per well of Hexyl Dye Solution into cell plates. Incubated for 20-35 minutes at room temp or ambient conditions.5) Dispensed 80 μL per well of Bath1 into compound plates. Acid Yellow-17 (1 mM) was added and Potassium Chloride was altered from 4.5 to 20 mM depending on the NaV subtype and assay sensitivity.6) Washed cell plates three times with 100 μL per well of Bath1, leaving 25 μL of residual volume. Then transfered 25 uL per well from Compound Plates to Cell Plates. Incubated for 20-35 minutes at room temp/ambient condition.7) Read Plate on E-VIPR. Used the current-controlled amplifier to deliver stimulation wave pulses for 10 seconds and a scan rate of 200 Hz. A pre-stimulus recording was performed for 0.5 seconds to obtain the un-stimulated intensities baseline. The stimulatory waveform was followed by 0.5 seconds of post-stimulation recording to examine the relaxation to the resting state.
- Assays for Detecting and Measuring of NaV Inhibition 1) Pre-spotted compounds (in neat DMSO) into compound plates. Vehicle control (neat DMSO), the positive control (20 mM DMSO stock tetracaine, 125 μM final in assay) and test compounds were added to each well at 160× desired final concentration in neat DMSO. Final compound plate volume was 80 μL (80-fold intermediate dilution from 1 μL DMSO spot; 160-fold final dilution after transfer to cell plate). Final DMSO concentration for all wells in assay was 0.625%. 2) Prepared Hexyl Dye Solution. 3) Prepared cell plates. On the day of the assay, medium was aspirated and cells were washed three times with 100 μL of Bath1 Solution, maintaining 25 μL residual volume in each well. 4) Dispensed 25 μL per well of Hexyl Dye Solution into cell plates. Incubated for 20-35 minutes at room temp or ambient conditions. 5) Dispensed 80 μL per well of Bath1 into compound plates. Acid Yellow-17 (1 mM) was added and Potassium Chloride was altered from 4.5 to 20 mM depending on the NaV subtype and assay sensitivity. 6) Washed cell plates three times with 100 μL per well of Bath1, leaving 25 μL of residual volume. Then transferred 25 uL per well from Compound Plates to Cell Plates. Incubated for 20-35 minutes at room temp/ambient condition.
7) Read Plate on E-VIPR. Used the current-controlled amplifier to deliver stimulation wave pulses for 10 seconds and a scan rate of 200 Hz. A pre-stimulus recording was performed for 0.5 seconds to obtain the un-stimulated intensities baseline. The stimulatory waveform was followed by 0.5 seconds of post-stimulation recording to examine the relaxation to the resting state.
- Electrophysiological Assay (EP) (In Vitro Assay) Patch voltage clamp electrophysiology allows for the direct measurement and quantification of block of voltage-gated sodium channels (NaV's), and allows the determination of the time- and voltage-dependence of block which has been interpreted as differential binding to the resting, open, and inactivated states of the sodium channel (Hille, B., Journal of General Physiology (1977), 69: 497-515).The following voltage clamp electrophysiology studies were performed on representative compounds using cells heterologously expressing Nav1.7 or Nav1.5 channels. cDNAs for Nav1.7 (NM_002977) and Nav1.5 (AC137587) were stably expressed in Chinese Hamstr Ovary (CHO) cells and CHL (Chinese Hamster Lung) cells respectively. Sodium currents were measured in the whole-cell configuration using Syncropatch 384PE (NanIon Technologies, Germany). 1NPC -384 chips with custom medium resistance and single hole mode are used. Internal solution consists of (in mM): 110 CsCl, 10 CsCl, 20 EGTA, and 10 Hepes (pH adjusted to 7.2); and external solution contains (in mM): 60 NMDG, 80 NaCl, 4 KCl, 1 MgCl2, 2 CaCl2, 2 D-Glucose monohydrate, 10 Hepes (pH adjusted to 7.4 with NaOH).After system flushing, testing compounds are dissolved in external solution containing 0.1% Pluronic F-127. The chip is moved into the measuring head and the instrument primes the chip with external and internal solutions. 10l cells are added to the chip from a cell hotel, and a negative pressure of −50 mBar is applied to form a seal. Following treatment with seal enhancer solution and wash-off with external solution, negative pressure of −250 mbar is applied for 1 second to achieve the whole-cell configuration, followed by three washing steps in external solution. 20 μl of compounds is added to 40 μl in each well (1:3 dilution of compounds), and after mixing, 20 μl is removed so the volume is retained at 40 μl. After approximately 13 minutes recordings, 20 μl/well of 2 uM TTX, or 333 uM Tetracaine (for Nav1.5) is added to achieve full block.For voltage protocol, an holding potential of −50 mV is applied during the whole experiment. A depolarizing step is applied to −10 mV for 10 ms, followed by a hyperpolarization step to −150 mV for 20 ms to allow channel recovery from inactivation. A second depolarizing step is applied from −150 mV to −10 mV for 10 ms, where currents were measured to derive blocking effects of compounds. Inhibition is determined based on 7.5 min of compound incubation.
- Electrophysiological Assay (EP) (In Vitro Assay) Patch voltage clamp electrophysiology allows for the direct measurement and quantification of block of voltage-gated sodium channels (NaV's), and allows the determination of the time- and voltage-dependence of block which has been interpreted as differential binding to the resting, open, and inactivated states of the sodium channel (Hille, B., Journal of General Physiology (1977), 69: 497-515).The following voltage clamp electrophysiology studies were performed on representative compounds using cells heterologously expressing Nav1.7 or Nav1.5 channels. cDNAs for Nav1.7 (NM_002977) and Nav1.5 (AC137587) were stably expressed in Chinese Hamstr Ovary (CHO) cells and CHL (Chinese Hamster Lung) cells respectively. Sodium currents were measured in the whole-cell configuration using Syncropatch 384PE (Nanlon Technologies, Germany). 1NPC -384 chips with custom medium resistance and single hole mode are used. Internal solution consists of (in mM): 110 CsCl, 10 CsCl, 20 EGTA, and 10 Hepes (pH adjusted to 7.2); and external solution contains (in mM): 60 NMDG, 80 NaCl, 4 KCl, 1 MgCl2, 2 CaCl2, 2 D-Glucose monohydrate, 10 Hepes (pH adjusted to 7.4 with NaOH).After system flushing, testing compounds are dissolved in external solution containing 0.1% Pluronic F-127. The chip is moved into the measuring head and the instrument primes the chip with external and internal solutions. 10 l cells are added to the chip from a cell hotel, and a negative pressure of −50 mBar is applied to form a seal. Following treatment with seal enhancer solution and wash-off with external solution, negative pressure of −250 mbar is applied for 1 second to achieve the whole-cell configuration, followed by three washing steps in external solution. 20 l of compounds is added to 40 l in each well (1:3 dilution of compounds), and after mixing, 20 l is removed so the volume is retained at 40 ul. After approximately 13 minutes recordings, 20 l/well of 2 uM TTX, or 333 uM Tetracaine (for Nav1.5) is added to achieve full block.For voltage protocol, an holding potential of −50 mV is applied during the whole experiment. A depolarizing step is applied to −10 mV for 10 ms, followed by a hyperpolarization step to −150 mV for 20 ms to allow channel recovery from inactivation. A second depolarizing step is applied from −150 mV to −10 mV for 10 ms, where currents were measured to derive blocking effects of compounds. Inhibition is determined based on 7.5 min of compound incubation.