Papillary muscle assays for preclinical safety studies

Action Potential Recordings from guinea-pig papillary muscles

Action potential recordings can be obtained using different tissular models. The sensitivity of action potential assays differs between species and cardiac tissue types. Their selection depends on the ion channels blocked by the compound. Here at PhysioStim, we use guinea-pig papillary muscles, rabbit atria and rabbit or dog purkinje fibers to answer all your study needs. Isolated papillary muscles from guinea-pigs are among the standard experimental preparations in cardiovascular research. This model also allows to investigate the effects of drugs on hKvLQT1/​MinK channels, available in this species. 

Why choose PhysioStim for your papillary muscle assays ?

The experts at PhysioStim respect all ICH guidelines to perform screening and GLP-compliant studies. Moreover, our stimulation protocol is designed to make sure you get the highest value out of your assay:

Technique

  • Conventional intracellular microelectrode technique

Study model

  • Guinea-pig papillary muscle
  • 6 preparations tested and 6 control preparations (as basic design protocol but can be adapted)

Reference product

  • Veratridine 1 µmol/L

Protocol

  • 3 cumulative increasing concentrations of assay compound
  • Stimulation rates: 1, 0.5 and 2 Hz (reverse use dependency)
  • Washout period or positive control at the end of the experiment

Measured parameters

  • Resting potential (mV)
  • Action Potential Amplitude (mV)
  • Action Potential Duration at 50%, 70% and 90% of repolarization: APD50, APD70, APD90 (ms)
  • Conduction time (ms)
  • Conduction speed (m/​s)
  • Maximal rate of depolarization: dV/dtmax (V/​s)
Action Potential Recordings from guinea-pig papillary muscles

Typical effects of veratridine effects on guinea-pig papillary muscles at 1 Hz

Advice from our expert scientists

In order to confirm the results of your action potential recordings and the impact on electrical activity or ECG, PhysioStim recommends completing your study with additional tests:

Need help with your preclinical safety studies ?

Please don’t hesitate to contact us