Table 1. Effects of dobutamine (0.1, 0.3, and 1 μM) on discharge profiles of AP recorded from ventricular cardiomyocytes isolated from adult mouse heart.
Averaged data were presented as mean ± SD, n = 12 myocytes from at least 4 mice. *P < 0.05 and **P < 0.01 vs control.
| Parameter | Control | 0.1 μM Dob | 0.3 μM Dob | 1 μM Dob | Washout |
|---|---|---|---|---|---|
| RMP | −79.4 ± 3.88 | −81.2 ± 3.47 | −83.6 ± 3.12* | −84.8 ± 3.44** | −80.6 ± 3.73 |
| APFT | −57.1 ± 4.13 | −58.8 ± 3.42 | −61.3 ± 4.05* | −63.6 ± 4.66** | −58.8 ± 3.99 |
| PeakAP | 56.1 ± 5.11 | 56.9 ± 4.23 | 57.8 ± 3.41 | 58.8 ± 3.18 | 58.2 ± 4.15 |
| APD50 | 3.87 ± 0.67 | 4.45 ± 0.81 | 5.51 ± 0.76* | 6.14 ± 0.64** | 4.33 ± 0.59 |
| % of APD50 | 100% | 114.98% | 142.38% | 158.66% | 111.89 |
| APD90 | 11.1 ± 2.04 | 13.0 ± 2.67 | 15.9 ± 3.82* | 17.7 ± 4.37** | 12.6 ± 4.02 |
| % of APD90 | 100% | 117.11 | 143.24% | 159.46% | 113.51% |
| UVMAX | 193 ± 20 | 237 ± 14* | 260 ± 17** | 266 ± 27** | 208 ± 15 |
| DVMAX | −28.3 ± 4.24 | −31.3 ± 4.36 | −37.9 ± 3.24* | −46.4 ± 3.88** | −33.6 ± 3.78 |
Note: RMP: resting membrane potential (mV); APFT: AP firing threshold (mV); PeakAP: the peak of AP (mV); APD50: AP duration measured at 50% of the height (ms); APD90: AP duration measured at 90% of the height (ms); UVMAX: the maximal upstroke velocity of depolarization (mV/ms); DVMAX: the maximal downstroke velocity of repolarization (mV/ms).