Table 5.

Percentage changes in APD in subEpi and subEndo cardiomyocytes after FCCP application in addition to 4-AP (2 mmol/L) (n = 4 for each).

	APD20 (%)	APD50 (%)	APD90 (%)
subEpi
4-AP	26.3 ± 1.2#,*	24.0 ± 2.0#,*	19.2 ± 1.3#,*
FCCP↑	2.2 ± 0.9#	4.4 ± 0.4#,*	6.3 ± 0.1#,*
FCCP 2.5′	–56.9 ± 1.8#,*	–56.4 ± 1.5#,*	–47.6 ± 1.1#,*
FCCP 5′	–83.3 ± 0.9#	–84.4 ± 0.6#	–79.7 ± 0.4#
subEndo
4-AP	15.3 ± 1.9*	16.7 ± 2.6*	14.8 ± 1.8*
FCCP↑	5.5 ± 0.6	10.1 ± 0.1	11.9 ± 0.1
FCCP 2.5′	–26.9 ± 0.8	–29.8 ± 1.2	–24.5 ± 0.4
FCCP 5′	–55.3 ± 2.6	–58.1 ± 2.7	–52.4 ± 2.6

Note that the depths of microelectrode insertion for subEpi and subEndo recordings were 0.48 ± 0.3 and 3.1 ± 0.2 mm from the epicardium, respectively. The positive/negative percentages show the prolongation/shortening of APs, respectively. Other notations are the same as in Table 1. ^∗p < 0.05 with 4-AP vs. without 4-AP (see Table 3) values obtained at the same time of FCCP action. ^#p < 0.05 subEpi vs. subEndo values obtained with 4-AP and at the same time of FCCP action.