Name: voltage-dependent potassium current recording on h9c2 cardiomyocytes via the whole-cell patch-clamp technique
Uploaded: 2022-11-11T15:00:00
Description: Watch this Scientific Journal Video about Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique at JoVE.com

We appreciate the financial support from the National Natural Science Foundation of China (82130113) and the Key R&#38;D and Transformation Program of the Science &#38; Technology Department of Qinghai Province (2020-SF-C33).

The commercially obtained H9c2 rat cardiomyocytes (see the Table of Materials) were incubated in DMEM containing 10% heat-inactivated fetal bovine serum (FBS) and 1% penicillin-streptomycin at 37 &#176;C in a 5% CO2&#160;humidified atmosphere. The whole-cell patch-clamp technique was then employed to detect the changes in IKv in normal H9c2 cells and 4-AP- or AC-treated cells (Figure 1 and Figure 2).
<p class="jove_titl...

<ol>
	<li>Luan, Q. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Passive+transport+and+ion+channels+in+biofilms.">Passive transport and ion channels in biofilms.</a> Acta Scientiarum Naturalium Universitatis Intramongoljcae. 2, 215-235 (1984).</li><li>Lei, M., Sun, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+the+mechanism+of+arrhythmia+induced+by+sodium+channel+disease.">Advances in the mechanism of arrhythmia induced by sodium channel disease.</a> Journal of Clinical Cardiology. 21 (4), 246-248 (2005).</li><li>Varr&#243;, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+transmembrane+ion+channels+and+action+potentials:+Cellular+physiology+and+arrhythmogenic+behavior.">Cardiac transmembrane ion channels and action potentials: Cellular physiology and arrhythmogenic behavior.</a> Physiological Reviews. 101 (3), 1083-1176 (2021).</li><li>Campuzano, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negative+autopsy+and+sudden+cardiac+death.">Negative autopsy and sudden cardiac death.</a> International Journal of Legal Medicine. 128 (4), 599-606 (2014).</li><li>Amin, A. S., Asghari-Roodsari, A., Tan, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+sodium+channelopathies.">Cardiac sodium channelopathies.</a> Pflu&#776;gers Archiv: European Journal of Physiology. 460 (2), 223-237 (2010).</li><li>Benitah, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltage+gated+Ca2++currents+in+the+human+pathophysiologic+heart:+A+review.">Voltage gated Ca2+ currents in the human pathophysiologic heart: A review.</a> Basic Research in Cardiology. 97 (1), 111-118 (2002).</li><li>Banyasz, T., Horvath, B., Jian, Z., Izu, L. T., Chen-Izu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequential+dissection+of+multiple+ionic+currents+in+single+cardiac+myocytes+under+action+potential-clamp.">Sequential dissection of multiple ionic currents in single cardiac myocytes under action potential-clamp.</a> Journal of Molecular and Cellular Cardiology. 50 (3), 578-581 (2011).</li><li>Nerbonne, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+basis+of+functional+myocardial+potassium+channel+diversity.">Molecular basis of functional myocardial potassium channel diversity.</a> Cardiac Electrophysiology Clinics. 8 (2), 257-273 (2016).</li><li>Grant, A. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+ion+channels.">Cardiac ion channels.</a> Circulation: Arrhythmia and Electrophysiology. 2 (2), 185-194 (2009).</li><li>Olson, T. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kv1.5+channelopathy+due+to+KCNA5+loss-of-function+mutation+causes+human+atrial+fibrillation.">Kv1.5 channelopathy due to KCNA5 loss-of-function mutation causes human atrial fibrillation.</a> Human Molecular Genetics. 15 (14), 2185-2191 (2006).</li><li>Christophersen, I. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+variation+in+KCNA5:+impact+on+the+atrial-specific+potassium+current+IKur+in+patients+with+lone+atrial+fibrillation.">Genetic variation in KCNA5: impact on the atrial-specific potassium current IKur in patients with lone atrial fibrillation.</a> European Heart Journal. 34 (20), 1517-1525 (2013).</li><li>Barry, D. M., Xu, H., Schuessler, R. B., Nerbonne, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+knockout+of+the+transient+outward+current,+long-QT+syndrome,+and+cardiac+remodeling+in+mice+expressing+a+dominant-negative+Kv4+alpha+subunit.">Functional knockout of the transient outward current, long-QT syndrome, and cardiac remodeling in mice expressing a dominant-negative Kv4 alpha subunit.</a> Circulation Research. 83 (5), 560-567 (1998).</li><li>Abbott, G. W., Xu, X., Roepke, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+ancillary+subunits+on+ventricular+repolarization.">Impact of ancillary subunits on ventricular repolarization.</a> Journal of Electrocardiology. 40, 42-46 (2007).</li><li>Jia, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+studies+on+the+application+of+patch-clamp+technique+in+cellular+electrophysiology.">Recent studies on the application of patch-clamp technique in cellular electrophysiology.</a> Journal of Chemical Engineering of Chinese Universities. 32 (4), 767-778 (2018).</li><li>Leuthardt, E. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+the+electrocorticographic+speech+network+to+control+a+brain-computer+interface+in+humans.">Using the electrocorticographic speech network to control a brain-computer interface in humans.</a> Journal of Neural Engineering. 8 (3), 1-3 (2011).</li><li>Tian, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+applying+progress+of+patch-clamp+technique.">The applying progress of patch-clamp technique.</a> Journal of Jilin Medical University. 4, 227-229 (2008).</li><li>Wang, Z. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+shensong+yangxin+capsule+on+c-type+Kv1.4+potassium+channel.">Effects of shensong yangxin capsule on c-type Kv1.4 potassium channel.</a> Chinese Heart Journal. 21 (6), 782-785 (2009).</li><li>Huang, X. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+resveratrol+on+Kv2.1+potassium+channels+in+cardiac+myocytes.">The effect of resveratrol on Kv2.1 potassium channels in cardiac myocytes.</a> Chinese Journal of Cardiac Pacing and Electrophysiology. 34 (5), 484-487 (2020).</li><li>Wang, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+neferine+on+Kv4.3+channels+expressed+in+HEK293+cells+and+ex+vivo+electrophysiology+of+rabbit+hearts.">Effects of neferine on Kv4.3 channels expressed in HEK293 cells and ex vivo electrophysiology of rabbit hearts.</a> Acta Pharmacologica Sinica. 36 (12), 1451-1461 (2005).</li><li>Gao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aconitine:+A+review+of+its+pharmacokinetics,+pharmacology,+toxicology+and+detoxification.">Aconitine: A review of its pharmacokinetics, pharmacology, toxicology and detoxification.</a> Journal of Ethnopharmacology. 293, 115270 (2022).</li><li>Zhou, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+efficacy+and+toxicity+of+aconitine:+A+new+frontier+for+the+ancient+poison.">Cardiac efficacy and toxicity of aconitine: A new frontier for the ancient poison.</a> Medicinal Research Reviews. 41 (3), 1798-1811 (2021).</li><li>An, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+tegaserod,+a+gastrokinetic+agent,+on+voltage-gated+K++channels+in+rabbit+coronary+arterial+smooth+muscle+cells.">The effects of tegaserod, a gastrokinetic agent, on voltage-gated K+ channels in rabbit coronary arterial smooth muscle cells.</a> Clinical and Experimental Pharmacology &amp; Physiology. 48 (5), 748-756 (2021).</li><li>Sun, Q., Liu, F., Zhao, J., Wang, P., Sun, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cleavage+of+Kv2.1+by+BACE1+decreases+potassium+current+and+reduces+neuronal+apoptosis.">Cleavage of Kv2.1 by BACE1 decreases potassium current and reduces neuronal apoptosis.</a> Neurochemistry International. 155, 105310 (2022).</li><li>Manz, K. M., Siemann, J. K., McMahon, D. G., Grueter, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch-clamp+and+multi-electrode+array+electrophysiological+analysis+in+acute+mouse+brain+slices.">Patch-clamp and multi-electrode array electrophysiological analysis in acute mouse brain slices.</a> STAR Protocols. 2 (2), 100442 (2021).</li><li>Kanda, H., Tonomura, S., Dai, Y., Gu, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protocol+for+pressure-clamped+patch-clamp+recording+at+the+node+of+Ranvier+of+rat+myelinated+nerves.">Protocol for pressure-clamped patch-clamp recording at the node of Ranvier of rat myelinated nerves.</a> STAR Protocols. 2 (1), 100266 (2021).</li><li>Ma, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+purity+human-induced+pluripotent+stem+cell-derived+cardiomyocytes:+electrophysiological+properties+of+action+potentials+and+ionic+currents.">High purity human-induced pluripotent stem cell-derived cardiomyocytes: electrophysiological properties of action potentials and ionic currents.</a> American Journal of Physiology-Heart and Circulatory Physiology. 301 (5), 2006-2017 (2011).</li><li>Yoshimura, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+in+vivo+patch-clamp+technique+to+pharmacological+analysis+of+synaptic+transmission+in+the+CNS.">Application of in vivo patch-clamp technique to pharmacological analysis of synaptic transmission in the CNS.</a> Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica. 124 (2), 111-118 (2004).</li><li>Aziz, Q., Nobles, M., Tinker, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-cell+and+perforated+patch-clamp+recordings+from+acutely-isolated+murine+sinoatrial+node+cells.">Whole-cell and perforated patch-clamp recordings from acutely-isolated murine sinoatrial node cells.</a> Bio-protocol. 10 (1), 3478 (2020).</li><li>Witchel, H. J., Milnes, J. T., Mitcheson, J. S., Hancox, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Troubleshooting+problems+with+in+vitro+screening+of+drugs+for+QT+interval+prolongation+using+HERG+K++channels+expressed+in+mammalian+cell+lines+and+Xenopus+oocytes.">Troubleshooting problems with in vitro screening of drugs for QT interval prolongation using HERG K+ channels expressed in mammalian cell lines and Xenopus oocytes.</a> Journal of Pharmacological and Toxicological Methods. 48 (2), 65-80 (2002).</li><li>Rodriguez-Menchaca, A. A., Ferrer, T., Navarro-Polanco, R. A., Sanchez-Chapula, J. A., Moreno-Galindo, E. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+the+whole-cell+patch-clamp+configuration+on+the+pharmacological+assessment+of+the+hERG+channel:+Trazodone+as+a+case+example.">Impact of the whole-cell patch-clamp configuration on the pharmacological assessment of the hERG channel: Trazodone as a case example.</a> Journal of Pharmacological and Toxicological Methods. 69 (3), 237-244 (2014).</li><li>Yang, S., Liu, Z. W., Zhang, Y. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+in+vivo+patch+clamp+technique.">The development of in vivo patch clamp technique.</a> Chinese Remedies &amp; Clinics. 5, 399-401 (2003).</li><li>Lin, Y. F., Ouyang, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Research+progress+and+application+of+patch+clamp+technique.">Research progress and application of patch clamp technique.</a> Strait Pharmaceutical Journal. 9, 8-11 (2008).</li><li>Li, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+insight+into+current+advances+on+pharmacology,+pharmacokinetics,+toxicity+and+detoxification+of+aconitine.">An insight into current advances on pharmacology, pharmacokinetics, toxicity and detoxification of aconitine.</a> Biomedicine &amp; Pharmacotherapy. 151, 113115 (2022).</li><li>Chan, T., Chan, J., Tomlinson, B., Critchley, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chinese+herbal+medicines+revisited:+A+Hong+Kong+perspective.">Chinese herbal medicines revisited: A Hong Kong perspective.</a> Lancet. 342 (8886-8887), 1532-1534 (1993).</li><li>Jiang, H., Zhang, Y. T., Zhang, Y., Wang, X. B., Meng, X. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+updated+meta-analysis+based+on+the+preclinical+evidence+of+mechanism+of+aconitine-induced+cardiotoxicity.">An updated meta-analysis based on the preclinical evidence of mechanism of aconitine-induced cardiotoxicity.</a> Frontiers in Pharmacology. 13, 900842 (2022).</li><li>Liu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocardial+toxicity+of+aconite+alkaloids.">Myocardial toxicity of aconite alkaloids.</a> Shenyang Pharmaceutical University. , (2007).</li><li>Li, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aconitine+blocks+HERG+and+Kv1.5+potassium+channels.">Aconitine blocks HERG and Kv1.5 potassium channels.</a> Journal of Ethnopharmacology. 131 (1), 187-195 (2010).</li><li>Campbell, D. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+kinetics+and+selectivity+of+sodium+channels+in+frog+skeletal+muscle+fibers+treated+with+aconitine.">Modified kinetics and selectivity of sodium channels in frog skeletal muscle fibers treated with aconitine.</a> The Journal of General Physiology. 80 (5), 713-731 (1982).</li><li>Huang, X. Y., Ying, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+specific+protein+1+on+Kv2.1+potassium+channel+in+cardiac+myocytes.">The effect of specific protein 1 on Kv2.1 potassium channel in cardiac myocytes.</a> Journal of Electrocardiology and Circulation. 39 (4), 338-341 (2020).</li><li>Cao, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+application+of+patch+clamp+technique.">Development and application of patch clamp technique.</a> Journal of Yuncheng University. 27 (2), 53-55 (2009).</li></ol>

The patch-clamp electrophysiological technique is mainly used to record and reflect the electrical activity and functional characteristics of ion channels on the cell membrane25. At present, the main recording methods of the patch-clamp technique include single-channel recording and whole-cell recording26. For the whole-cell mode, the glass microelectrode and negative pressure are used to form a high-resistance seal between a small area of the cell membrane and a pipette ti...

Ion channels are special integrated proteins embedded in the lipid bilayer of the cell membrane. In the presence of activators, the centers of such special integrated proteins form highly selective hydrophilic pores, allowing ions of an appropriate size and charge to pass through in a passive transport manner1. Ion channels are the basis of cell excitability and bioelectricity and play a key role in a variety of cellular activities2. The heart supplies blood to other organs through regular contractions resulting from an excitation-contraction-coupled process initiated by action potentials3. Previous studies have confirmed that the generation of action potentials in cardiomyocytes is caused by the change in intracellular ion concentration, and the activation and inactivation of Na+, Ca2+, and K+ ion channels in human cardiomyocytes lead to the formation of action potentials in a certain sequence4,5,6. Disturbed voltage-gated potassium (Kv) channel currents (IKv) could change the normal heart rhythm, leading to arrhythmias, which are one of the leading causes of death. Therefore, recording the IKv is critical for understanding the mechanisms of drugs for treating life-threatening arrhythmias7.
The Kv channel is an important component of the potassium channel. The coordination function of the Kv channel plays an important role in the electrical activity and myocardial contractility of the mammalian heart8,9,10. In cardiomyocytes, the amplitude and duration of action potentials depend on the co-conduction of outward K+ currents by multiple Kv channel subtypes11. The regulation of the Kv channel function is very important for the normal repolarization of the cardiac action potential. Even the slightest change in Kv conductance greatly impacts cardiac repolarization and increases the possibility of arrhythmia12,13.
Representing a fundamental method in cellular electrophysiological research, a high-resistance seal between a small area of the cell membrane and a pipette tip for whole-cell patch-clamp recording can be established by applying a negative pressure. The continuous negative pressure makes the cell membrane come into contact with the pipette tip and stick onto the inner wall of the pipette. The resulting complete electrical circuit allows one to record any single ion channel current across the surface of the cell membrane14. This technique has a very high sensitivity for the cell membrane ion channel current and can be used to detect currents in all ion channels, and the applications are extremely broad15. Moreover, compared with fluorescent labeling and radioactive labeling, patch-clamp has higher authority and accuracy16. At present, the whole-cell patch-clamp technique has been used to detect the traditional Chinese medicine components acting on Kv channel currents17,18,19. For example, Wang et al. used the whole-cell patch-clamp technique and confirmed that the effective component of the lotus seed might achieve the inhibition of the Kv4.3 channel by blocking the activated state channels19. Aconitine (AC) is one of the effective and active ingredients of Aconitum species, such as Aconitum carmichaeli Debx and Aconitum pendulum Busch. Numerous studies have shown that overdoses of AC can cause arrhythmias and even cardiac arrest20. The interaction between AC and voltage-gated ion channels leads to the disruption of intracellular ion homeostasis, which is the key mechanism of cardiotoxicity21. Therefore, in this study, the whole-cell patch-clamp technique is used to determine the effects of AC on the IKv of cardiomyocytes.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>4-Aminopyridine</td>
			<td>Sigma</td>
			<td>MKCJ2184</td>
			<td></td>
		</tr>
		<tr>
			<td>Aconitine</td>
			<td>Chengdu Lemetian Medical Technology Co., Ltd</td>
			<td>DSTDW000602</td>
			<td></td>
		</tr>
		<tr>
			<td>Amplifier</td>
			<td>Axon Instrument</td>
			<td>MultiClamp 700B</td>
			<td></td>
		</tr>
		<tr>
			<td>Analytical Balance</td>
			<td>Sartorius</td>
			<td>124S-CW</td>
			<td></td>
		</tr>
		<tr>
			<td>ATP Na2</td>
			<td>Solarbio</td>
			<td>416O022</td>
			<td></td>
		</tr>
		<tr>
			<td>Borosilicate glass with filament (O.D.: 1.5 mm, I.D.: 1.10 mm, 10 cm length)&#160;</td>
			<td>Sutter Instrument</td>
			<td>163225-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture dish (100 mm)</td>
			<td>Zhejiang Sorfa Life Science Research Co., Ltd</td>
			<td>1192022</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture dish (35 mm)</td>
			<td>Zhejiang Sorfa Life Science Research Co., Ltd</td>
			<td>3012022</td>
			<td></td>
		</tr>
		<tr>
			<td>Clampex software</td>
			<td>Molecular Devices, LLC.</td>
			<td>Version 10. 5</td>
			<td></td>
		</tr>
		<tr>
			<td>Clampfit software</td>
			<td>Molecular Devices, LLC.</td>
			<td>Version 10. 6. 0. 13</td>
			<td>data acqusition software</td>
		</tr>
		<tr>
			<td>D-(+)-glucose</td>
			<td>Rhawn</td>
			<td>RH289133</td>
			<td></td>
		</tr>
		<tr>
			<td>Digital camera</td>
			<td>Hamamatsu</td>
			<td>C11440</td>
			<td></td>
		</tr>
		<tr>
			<td>Digitizer</td>
			<td>Axon Instrument</td>
			<td>Axon digidata 1550B</td>
			<td></td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>Boster Biological Technology Co., Ltd</td>
			<td>PYG0040</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified eagle medium (1x)</td>
			<td>Gibco</td>
			<td>8121587</td>
			<td></td>
		</tr>
		<tr>
			<td>EGTA</td>
			<td>Biofroxx</td>
			<td>EZ6789D115</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Gibco</td>
			<td>2166090RP</td>
			<td></td>
		</tr>
		<tr>
			<td>Flaming/brown micropipette puller</td>
			<td>Sutter Instrument</td>
			<td>Model P-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>H9c2 cells</td>
			<td>Hunan Fenghui Biotechnology Co., Ltd</td>
			<td>CL0111</td>
			<td></td>
		</tr>
		<tr>
			<td>HCImageLive</td>
			<td>Hamamatsu</td>
			<td>4.5.0.0</td>
			<td></td>
		</tr>
		<tr>
			<td>HCl</td>
			<td>Sichuan Xilong Scientific Co., Ltd</td>
			<td>2106081</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Xiya Chemical Technology (Shandong) Co., Ltd</td>
			<td>20210221</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Chengdu Colon Chemical Co., Ltd</td>
			<td>2020082501</td>
			<td></td>
		</tr>
		<tr>
			<td>KOH</td>
			<td>Chengdu Colon Chemical Co., Ltd</td>
			<td>2020112601</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Tianjin Guangfu Fine Chemical Research Institute</td>
			<td>20160408</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2&#183;6H2O</td>
			<td>Chengdu Colon Chemical Co., Ltd</td>
			<td>2021020101</td>
			<td></td>
		</tr>
		<tr>
			<td>Micromanipulator</td>
			<td>Sutter Instrument</td>
			<td>MP-285A</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Olympus</td>
			<td>IX73</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope cover glass (20 &#215; 20 mm)</td>
			<td>Jiangsu Citotest Experimental Equipment Co. Ltd</td>
			<td>80340-0630</td>
			<td></td>
		</tr>
		<tr>
			<td>Milli-Q</td>
			<td>Chengdu Bioscience Technology Co., Ltd</td>
			<td>Milli-Q IQ 7005</td>
			<td></td>
		</tr>
		<tr>
			<td>MultiClamp 700B commander</td>
			<td>Axon Instrument</td>
			<td>MultiClamp commander 2.0</td>
			<td>signal-amplifier software&#160;</td>
		</tr>
		<tr>
			<td>OriginPro 8 software</td>
			<td>OriginLab Corporation</td>
			<td>v8.0724(B724)</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (100x)</td>
			<td>Boster Biological Technology Co., Ltd</td>
			<td>17C18B16</td>
			<td></td>
		</tr>
		<tr>
			<td>PH&#160;meter&#160;</td>
			<td>Mettler Toledo</td>
			<td>S201K</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (1x)</td>
			<td>Gibco</td>
			<td>8120485</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin 0.25% (1x)</td>
			<td>HyClone</td>
			<td>J210045</td>
			<td></td>
		</tr>
	</tbody>
</table>

voltage-dependent potassium current recording on h9c2 cardiomyocytes via the whole-cell patch-clamp technique

Potassium channels on the myocardial cell membrane play an important role in the regulation of cell electrophysiological activities. Being one of the main ion channels, voltage-gated potassium (Kv) channels are closely associated with some serious heart diseases, such as drug-induced myocardial damage and myocardial infarction. In the present study, the whole-cell patch-clamp technique was employed to determine the effects of 1.5 mM 4-aminopyridine (4-AP, a broad-spectrum potassium channel inhibitor) and aconitine (AC, 25 &#181;M, 50 &#181;M, 100 &#181;M, and 200 &#181;M) on the Kv channel current (IKv) in H9c2 cardiomyocytes. It was found that 4-AP inhibited the IKv by about 54%, while the inhibitory effect of AC on the IKv showed a dose-dependent trend (no effect for 25 &#181;M, 30% inhibitory rate for 50 &#181;M, 46% inhibitory rate for 100 &#181;M and 54% inhibitory rate for 200 &#181;M). Due to the characteristics of higher sensitivity and precision, this technique will promote the exploration of cardiotoxicity and the pharmacological effects of ethnomedicine targeting ion channels.

This protocol allowed the recording of the IKv according to the parameters set in the whole-cell patch-clamp technique. The IKv was triggered by 150 ms of depolarizing pulse stimulus from &#8722;40 to +60 mV at a holding potential of &#8722;60 mV (Figure 3A). The IKv of the H9c2 rat cardiomyocytes first appeared around &#8722;20 mV, and then the amplitude increased with further depolarization. The mean relationship between the IKv and membrane pote...

Watch this Scientific Journal Video about Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique at JoVE.com

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique

The present protocol describes an efficient method for the real-time and dynamic acquisition of voltage-gated potassium (Kv) channel currents in H9c2 cardiomyocytes using the whole-cell patch-clamp technique.

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique

Potassium channels on the myocardial cell membrane play an important role in the regulation of cell electrophysiological activities. Being one of the main ...

This protocol successfully records the effects of the aconitine on the IKv of H9C2 cells. Promoting new phases for investigating the mechanism of cardiotoxicity of drugs from the perspective of ion channels. The whole-cell patch-clamp technique is the gold standard of ion channel research with high sensitivity, high precision, and high specificity.The whole-cell patch-clamp technique can be employed to explore the pharmacological or toxic mechanisms of juxta gating specific ion channels for multisystem diseases, such as cardiovascular system and nervous system. To begin, digest the cells with 0.25%trypsin for 30 seconds, once the H9C2 culture dish becomes 80%confluent. Culture 2 times 10 to the 5th cells per milliliter with normal medium or drug containing medium in a 35 millimeter dish carpeted with glass plates for 24 hours at 37 degrees celsius, with a 5%carbon dioxide atmosphere and 70 to 80%relative humidity.Turn on the micropipette puller and preheat for 30 minutes. Then put a borosilicate glass capillary with a filament on the micropipette puller. Select the program and click on enter on the control panel.Click on the ramp program in the upper right corner to determine the heat value of the glass capillary. Write the program for pulling the electrode according to the value determined by the ramp test and click on pull to start fabricating the pipettes. Turn on the digital analog converter, the signal amplifier, the micro manipulator, the microscope, and the camera.Open the imaging application, the signal amplifier software and the data acquisition software in sequence. Click on acquire and select edit protocol in the data acquisition software. Edit the program in the waveform interface.Enter values for first level, delta level, first duration, and delta duration for epoch A, epoch B, and epoch C.Then click on the mode rate interface and set the trial hierarchy data. Next, click on edit protocol to select the stimulus button and set the leak subtraction program in the PM leak subtraction dialogue box. To establish the data storage path, click on file and select set data file names in the data acquisition software.Then open the established lKv protocol by selecting acquire and clicking on open protocol in the data acquisition software. Finally, click on the tools option, and select membrane test to start running the protocol. Add the extracellular solution to the cell bath on the whole-cell patch-clamp apparatus and place the cover slip upward with the H9C2 cells in the bath.Fill 30%of the pipette with the extracellular solution and install it on the recording electrode holder integrated into the patch-clamp apparatus. Tighten the pipette with the recording electrode holder. Then drop the pipette into the bath with the micro manipulator.Click on the pipette offset interface of the signal amplifier software to maintain the lKv current baseline at zero picoamps. Deliver an appropriate positive pressure manually with a 1.0 milliliter syringe, connected to the recording electrode holder, through a plastic tube. Move the pipette slightly by manipulating the micromanipulator in three dimensions to contact the cell.Once the membrane tests square wave drops by one third to a half after the pipette touches the cell membrane, remove the positive pressure and manually deliver an appropriate negative pressure. Then click on the patch interface of the data acquisition software to form the gigaseal. Use the capacitance compensation fast and capacitance compensation slow signal amplifier software during cell ceiling to compensate for the fast and slow capacitance.Apply brief pulses of negative pressure to rupture a patch of the cell membrane. Execute whole-cell membrane capacitance compensation by clicking on the whole-cell button of the signal amplifier software. Finally, save and record the data, by clicking on the data recording button.Open the saved lKv data with the data analysis software. Save the current voltage relationships. Click on analyze to select statistics.Select the range as Cursors 1 2 for data analysis, click on the peak amplitude and mean buttons and then click on okay to view the data in the results page. Finally, copy the column of lKv mean data into the function drawing software for further analysis. Save the representative lKv current traces.Click on edit to select transfer traces, then select the full trace in the region to transfer. Next, click on select in trace selection and select IN 0 in signals. Finally, click on okay to view the data in the results page and copy the total data into the function drawing software to draw the current traces.Save the lKv protocol. Click on edit to select create stimulus waveform signal and select okay. Then repeat the step for drawing current traces without selecting the signal.The lKv was triggered by 150 milliseconds of depolarizing pulse stimulus from minus 40 to plus 60 millivolts at holding potential of minus 60 millivolts. The lKv of the H9C2 rat cardiomyocytes, first appeared around minus 20 millivolts, and then the amplitude increased with further depolarization. In comparison with the control group, the lKv amplitude was observably reduced after the five minutes of treatment with 1.5 millimolar 4-AP.Additionally, the lKv decreased significantly at membrane potentials from 10 to 60 millivolts in a dose-dependent manner, after the 24 hours AC treatment. The individual cell after recording ion channel, can be used for further single-cell omics assess, such as single-cell genomics, transcriptomics, proteomics, and the metabolomics.

Research

JoVE Journal

Medicine

Technique and Considerations in the Use of 4x1 Ring High-definition Transcranial Direct Current Stimulation (HD-tDCS)

Technique and Considerations in the Use of 4x1 Ring High-definition Transcranial Direct Current Stimulation HD-tDCS

High-definition transcranial direct current stimulation (HD-tDCS) has recently been developed as a noninvasive brain stimulation approach that increases ...

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection

Stroke is a leading cause of death, disability, and socioeconomic loss worldwide. The majority of all strokes result from an interruption in blood flow ...

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal ...

A Technique for Subcutaneous Abdominal Adipose Tissue Biopsy via a Non-diathermy Method

Adipose tissue biopsies offer tissue samples that, upon analysis, may provide insightful overviews of mechanisms relating to metabolism and disease. To ...

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Cardiac sarcoplasmic reticulum ...

Isolation and Cultivation of Adult Rat Cardiomyocytes

In an intact heart, adjacent cells influence adult cardiomyocytes. With the method of isolation and cultivation of adult cardiomyocytes, a precise ...

Updated Technique for Reliable, Easy, and Tolerated Transcranial Electrical Stimulation Including Transcranial Direct Current Stimulation

Transcranial direct current stimulation (tDCS) is a noninvasive method of neuromodulation using low-intensity direct electrical currents. This method of ...

In Vitro Assessment of Cardiac Function Using Skinned Cardiomyocytes

In this article, we describe the steps required to isolate a single permeabilized (&#34;skinned&#34;) cardiomyocyte and attach it to a force-measuring ...

High-Throughput Optical Controlling and Recording Calcium Signal in iPSC-Derived Cardiomyocytes for Toxicity Testing and Phenotypic Drug Screening

Understanding how excitable cells work in health and disease and how that behavior can be altered by small molecules or genetic manipulation is important. ...

Technical Applications of Microelectrode Array and Patch Clamp Recordings on Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Drug-induced cardiotoxicity is the leading cause of drug attrition and withdrawal from the market. Therefore, using appropriate preclinical cardiac safety ...