Table 1.
Control experimental conditions used for human atrial cell electrophysiological recordings, including intra- and extra-cellular ionic constituents, [Ca2+]i-buffering and temperature (all closely matching and within mammalian physiological ranges), recording configurations and measurements taken.
| Study | WL_2001 (Workman et al., 2001) | WL_2006 (Workman et al., 2006) | WL_2007 _ICAL (Pau et al., 2007) | WL_2012 _IK1 (Marshall et al., 2012) | WL_2012 _ITO (Workman et al., 2012) |
|---|---|---|---|---|---|
| Intracellular solution constituents (mM, pH) | L-aspartate (110), KCl (20), MgCl2 (1.0), EGTA (0.15), Na2ATP (4.0), Na2GTP (0.4), HEPES (5.0), pH 7.3 | For ruptured-patch: K-aspartate (110), KCl (20), MgCl2 (1.0), EGTA (0.15), Na2ATP (4.0), Na2GTP (0.4), HEPES (5.0), nystatin (0.18); pH 7.3 For perforated-patch: KCl (30), HEPES (5.0), MgCl2 (1.0), K methane-sulfonic acid (100), NaCl (5.0); pH 7.3 | KCl (30), HEPES (5), MgCl2 (1), K methane-sulfonic acid (100), NaCl (5), nystatin (0.18); pH 7.3 | K-aspartate (110), KCl (20), MgCl2 (1.0), EGTA (0.15), Na2ATP (4.0), Na2GTP (0.4), HEPES (5.0); pH 7.3 | K-aspartate (130), KCl (15), NaCl (10), MgCl2 (1), HEPES (10), EGTA (0.1); pH 7.3 |
| Extracellular solution constituents (mM, pH) | NaCl (130), KCl (4.0), CaCl2 (2.0), MgCl2 (1.0), glucose (10), HEPES (10), pH 7.4 | NaCl (130), KCl (4.0), CaCl2 (2.0), MgCl2 (1.0), glucose (10), HEPES (10); pH 7.4 | NaCl (130), KCl (4.0), CaCl2 (2.0), MgCl2 (1.0), glucose (10), HEPES (10), pH 7.4 | NaCl (130), KCl (4.0), MgCl2 (1.0), CaCl2 (2.0), glucose (10), HEPES (10); pH 7.4 | NaCl (140), KCl (4.0), CaCl2 (1.8), MgCl2 (1.0), glucose (11), HEPES (10); pH 7.4 |
| LLJP correction | Yes | Yes | Yes | Yes | Yes |
| Recording temperature | 35–37°C | 35–37°C | 35–37°C | 35–37°C | 35–37°C |
| [Ca2+]i-buffering | Minimal (0.15 mM EGTA) | Minimal (0.15 mM EGTA for ruptured-patch; zero EGTA for perforated-patch) | Minimal (zero EGTA as perforated-patch) | Minimal (0.15 mM EGTA) | Minimal (0.10 mM EGTA) |
| Cell isolation enzyme | Collagenase (Type 1, Worthington, 400 U/ml) | Collagenase (Type 1, Worthington, 400 U/ml) | Collagenase (Type 1, Worthington, 400 U/ml) | Collagenase (Type 1, Worthington, 400 U/ml) | Collagenase (Type 1, Worthington, 400 U/ml) |
| Patch configuration | Ruptured patch | Ruptured patch Nystatin-perforated patch | Nystatin-perforated patch | Ruptured patch | Ruptured patch |
| Patch-clamp amplifier | Axopatch-1D (Axon) | Axopatch-1D (Axon) | Axopatch-1D (Axon) | Axopatch-1D (Axon) | AxoClamp 2B (Axon) |
| Recording configuration | Current-clamp Voltage-clamp | Current-clamp Voltage-clamp | Current-clamp Voltage-clamp | Voltage-clamp | Current-clamp Voltage-clamp Dynamic-clamp |
| Measurements | APs, ERP, ICaL, ITO, IK1, IKSUS | APs, ERP, ICaL, ITO, IK1, IKSUS | APs, ERP, ICaL | ITO, IK1, IKSUS | APs, ITO |
LLJP, liquid-liquid junction potential; AP, action potential; ERP, cellular effective refractory period; ICaL, L-type Ca2+ current; Ito, transient outward K+ current; IK1, inward rectifier K+ current; Isus, sustained outward K+ current (mainly IKur).