Table 2.

Effect of 4-AP on endothelial and vascular smooth muscle cell membtane potential (mV) in the absence and presence of 18βGA

	Endothelium			Vascular smooth muscle
	Before	After	Δ	Before	After	Δ
4-AP (n = 15,11)	−38.9 ± 1.4	−27.9 ± 0.7†	+11.0 ± 1.0	−46.3 ± 1.8	−36.4 ± 1.8†	+10.0 ± 1.0
4-AP (before 18βGA) (n = 6,6)	−40.2 ± 1.7	−27.8 ± 2.0†	+12.4 ± 3.9	−43.4 ± 2.5	−34.2 ± 2.4†	+9.2 ± 1.1
4-AP (after 18βGA)* (n = 6,6)	−34.7 ± 1.7	−33.0 ± 1.4	+1.7 ± 1.0‡	−47.4 ± 2.7	−36.9 ± 3.3†	+10.5 ± 1.1

^*Paired impalements maintained during 4-AP application in the absence and presence of 18βGA.

^†Significantly different from value of membrane potential in the absence of 4-AP(P < 0.01)

^‡Significantly different from changes in membrance potential due to 4-AP in the absence of 18βGA (P < 0.01).