AChR STUDY WITH CYTOPATCH™
CytoPatch™ study: Measurement of currents through ligand gated ion channels
Original current traces recorded with the CytoPatchTM instrument, showing the inhibitory action of CTX on acetylcholine evoked inward currents in TE671 cells. After a washout period of 10 minutes the antagonist was nearly completely dissociated from the receptor.
In this study, the applicability of the CytoPatch™ instrument for the investigation of compounds acting on ligand gated channels (LIGCs) was demonstrated. As a model for ligand gated ion channels the nicotinic acetylcholine receptor was chosen. The receptor was expressed in TE671 cells. The action of agonists and antagonists was investigated by whole cell measurements at the CytoPatch™ instrument.
Agonist applications led to rapid inward currents carried by sodium ions. The onset of currents is comparable to recordings that have been obtained at a manual patch clamp setup. The rise time from base to peak is in the order of 50 ms. EC50 values for acetylcholine and epibatidine applications were estimated at the CytoPatch™ instrument and nicely fit to values obtained with manual patch clamp setup using the Dynaflow™ that is among the best compound application systems for manual patch clamp setups (EC50 values for conventional patch clamp/ CytoPatch™ instrument: acetylcholine: 7.1 / 5.0; epibatidine: 0.33 / 1.07).
Our EC50 and IC50 values are in excellent agreement with data from the literature. This indicates that the CytoPatch™ is highly suitable for investigating ligand gated ion channels. The innovative microfluidic system enables very rapid compound applications. Additionally it is also possible to superfuse the cell with an antagonist containing solution and then rapidly apply the agonist for a short defined period, as needed for the thorough investigation of modulators of ligand gated ion channels.
Thus the data reflect that this automated patch clamp device is highly suitable not only for pharmaceutical requirements in early drug discovery process and in safety pharmacology, but also for academic research purposes.