Application Note

Channel:Cells:
Tools:

INa, ICa , IK
ES cell-derived
cardiomyocytes
Patchliner®

Recordings of Action Potentials in Mouse ES
Cell-Derived Cor.At® Cardiomyocytes onNanion's Patchliner®
The electrophysiology team at Nanion Technologies GmbH, Munich, Germany.
Axiogenesis AG, Cologne, Germany.
Introduction

Results

Axiogenesis is a provider of pure mouse embryonic

Action potentials recorded in the current clamp mode ofstem cell-derived cardiomyocytes (Cor.At® (1)). TheseCor.At® cardiomyocytes were sensitive to the ion channel

cardiomyocytes have been evaluated with Nanion’s

modulators Quinidine and Lidocaine (Fig. 3).

automated patch clamp platforms the Port-a-Patch®
(2) and the Patchliner®. The aim of this study was toAcontrol

10 µM Quinidine

washout

50 µM Lidocaine

washoutshow that the Patchliner®, Nanion´s planar patch clamp
device for increased throughput, can be used for studies
investigating compounds which exhibit chronotropic or+ 40 pA

arrhythmic effects. In the voltage clamp mode voltagedependent Na+-, Ca2+­- and K+-channel currents could berecorded (Fig. 1). As expected, action potentials could
be elicited in the current clamp mode (Fig. 2). Effects ofI (memb)

controlB

compounds on action potentials have been successfullydemonstrated.
AB

C+ 40 pA
I (memb)
100 pA

40 pA
200 ms

50 ms

400 pA
10 ms

C

Figure 1:
Ion channel recordings in Cor.At® cardiomyocytes. A mERG currents­showed ­approximately 50 pA outward current. B After inactivating T-type­calcium currents with a pre-pulse, L-Type calcium current were elicited byvoltage steps from -40 mV to +60 mV. C Na+-channel mediated currents.
2 ms stimulus (500 pA)
I (memb)

0 mV

0 mV
40 mV

40 mV

100 ms
100 msFigure 2:
Action potentials in Cor.At® cells, A, recorded with a conventional patch
clamp rig (Dr. Davide Pau, Scottish Biomedical Ltd., Glasgow, UK), B,
recorded with a Patchliner®. The action potential was elicited by a 2 ms
pulse to 500 pA. Before and after the stimulation, the cell was kept at theholding current which corresponded to -80 mV.

Download more Application Notes from www.nanion.decontrol
10 µM Quinidine
washoutcontrol
50 µM Lidocainewashout
20 mV
70 ms

Figure 3:
Pharmacological experiments. A Action potentials in control conditions, inthe presence of 10 µM Quinidine and after washout. B Action potentials incontrol conditions, in the presence of the Na+-channel blocker Lidocaine(50 µM) and after washout. Same cell as in A. C Overlay of three tracesfrom the recordings shown in A and B. The action potentials were elicitedby depolarisation from a holding current I(memb) to +40 pA for 150 ms with asweep interval of 10 s.

Application NoteSummary
The human Ether-a-go-go Related Gene (hERG) encodes

Cor.At® cardiomyocytes display typical cardiac ion

a K+-channel, which is responsible for the repolarising IKrchannel activity and action potentials. Both the hERG

current in the human cardiac action potential. The hERG

blockers Quinidine and Cisapride, and the Na+-channel

blocker Cisapride induced a change of the repolarisation

blocker Lidocaine, modulated the action potentials. The(Fig. 4), which indicates functionality of the mouse

Quinidine and Lidocaine effects were reversible, theanalogue of hERG-channels in Cor.At® cardiomyocytes.

Cisapride effect was non-reversible.

The effect was non-reversible upon washout.

The results demonstrate the presence of an array of ion

Achannels in Cor.At® cardiomyocytes which in conjunction

B

are capable of generating action potentials. Hencecontrol
100 nM Cisapridethese stem cell-derived cardiomyocytes are a suitable

0 mV

alternative to primary cardiomyocytes in drug screening
and safety testing.

50 mV

In addition, these experiments demonstrate for the first

20 pA
200 ms

100 mstime the suitability of a higher throughput planar patch

Figure 4:
Cisapride block of mERG. A mERG current in the voltage clamp mode,
before and after the application of 100 nM Cisapride. B Action potential
before and after the application of the hERG specific blocker. Afterapplication of 100 nM Cisapride, the repolarisation of the action potential
was slower. This hints to a mERG channel block, since the hERG channel
analog is, like in human action potentials, responsible for the repolarisationof action potentials in mouse fetal cardiomyocyte-like Cor.At® cells. Theaction potential was elicited by a 1 ms pulse to 200 pA. After the stimulation,
the cell was kept at the basal level with no current injection (0 pA) for 500
ms. The holding current corresponded to -80 mV.

clamp system, i.e. Nanion´s Patchliner®, for recording
action potentials. This is possible because of the flexibilityof Nanion‘s patch clamp systems allowing for a multitudeof different experiments to be performed in both voltage
and current clamp modes.
Cells expressing multiple ion channels and therefore able
to elicit action potentials, as opposed to cell lines overexpressing a single ion channel subtype, better represent
the physiological system. Thus, the Patchliner®

incombination with Cor.At® cardiomyocytes form apowerful tool for ion channel research, drug screening
and safety testing.

Methods
Electrophysiology

Cells
Mouse embryonic stem cell-derived cardiomyocytes,
ready to use and 99.9 % pure without contamination byother cell types (1).

Whole cell patch clamp recordings were conducted­according to Nanion’s standard procedure for the­Patchliner®. Protocol for ion channel recordings see (2).
References

Patch Clamp Solutions
External solution for Ca2+-channel recordings: 80 mM NaCl,(1) Cor.At® cardiomyocytes from Axiogenesis AG, Cologne,

3 mM KCl, 10 mM MgCl2, 35 mM CaCl2, 10 mM HEPES (Na -Germany; www.axiogenesis.com, email: info@axiogenesis.

salt)/HCl, pH 7.4. External solution in voltage clamp andcom.

current clamp recordings: 140 mM NaCl, 4 mM KCl, 1 mM

(2) Recordings of Action Potentials in Cor.At cells on Nanion´sMgCl2, 2 mM CaCl2, 5 mM D-Glucose monohydrate, 10 mM

Port-a-Patch®. www.nanion.de+

HEPES /NaOH pH 7.4. Internal solution: 50 mM KCl, 10 mM
NaCl, 60 mM KF, 20 mM EGTA, 10 mM HEPES /KOH, pH 7.2.

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