TABLE 3

Changes in action potential parameters of human atrial myocytes by DPO-1

Parameters measured at increasing concentrations of DPO-1 were compared with control parameters and analyzed as described under Materials and Methods. Average injected hyperpolarizing current to set RMP close to -80 mV under control conditions was 80 ± 4.06 pA (n = 14).

Parameter	Control	0.1 μM (n = 4)	0.2 μM (n = 7)	1 μM (n = 7)	Wash (n = 6)
RMP (mV)	-84.3 ± 2.36 (n = 14)	-88.45 ± 5.02	-83.84 ± 1.18	-85.03 ± 1.92	-84.5 ± 1.23
APA (mV)	118.33 ± 3.00 (n = 14)	0.18 ± 1.39^a	3.11 ± 0.96^a	2.78 ± 2.02^a	0.36 ± 1.97^a
APD₉₀ (ms)	212.66 ± 34.76 (n = 14)	11.22 ± 12.23^a	49.28 ± 16.31*^a	49.43 ± 8.18*^a	15.80 ± 4.42^a
APD₅₀ (ms)	94.14 ± 20.45 (n = 14)	25.04 ± 18.83^a	117.58 ± 34.69*^a	114.81 ± 27.58*^a	23.43 ± 12.45^a
APA @ 50 ms	72.26 ± 5.32 (n = 10)	15.36 ± 13.24^a	53.25 ± 9.34*^a	59.28 ± 7.88*^a	21.63 ± 9.62^a

APA @ 50 ms, action potential amplitude measured at 50 ms.
↵* P < 0.05.
↵ a Averaged percentage change from control.