REPOLARISATION ASSAYS
SINGLE VENTRICULAR MYOCYTES
STABILITY OF ACTION POTENTIAL DURATION
UNDER CONTROL CONDITIONS
As noted in the ãˆ
Guidelines on Safety Pharmacology Studies for Human
Pharmaceuticals艃H S7B section 3.2.2.1) <b>action potential
duration studies using disaggregated cardiac myocytes provide a
powerful approach</b> to elucidate the ionic current mechanism
responsible for a change in action potential parameters.
Although this preparation requires a degree of technical
expertise we at OCP have over
15 years experience in using such preparations and have the
skill and expertise to consistently produce stable recordings of
the highest quality.
Figure 1
Stability of action potential duration in a single guinea-pig ventricular myocyte.
Figure 1
shows 10 consecutive action potential records
taken from a single left ventricular myocyte
under our standard
experimental conditions used for the action potential
measurements. These data demonstrate that measurements of
action potential duration were stable under the conditions of
these experiments.
It has
been demonstrated that repolarisation assays using single
ventricular myocytes provide results that are comparable to other preparations (such
as dog Purkinje fibres) for assessing the effects of compounds
that cause QT prolongation, including sotalol
and dofetilide (also see
www.physoc.org/Proceedings/Abstracts/544P/Files/S156.html).
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