Table 3.

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

	Endothelium			Vascular smooth muscle
	Before	After	Δ	Before	After	Δ
ACh (n = 3, 3)	−35.7 ± 1.8	−47.3 ± 1.0†	−11.7 ± 1.1	−43.3 ± 3.0	−55.2 ± 2.0†	−11.8 ± 1.6
ACh +l-NNA* (n = 3, 3)	−35.3 ± 2.4	−44.3 ± 2.4†	−12.0 ± 1.8	−40.7 ± 2.4	−41.5 ± 3.1‡	−0.8 ± 1.0‡
ACh (n = 16, 16)	−39.8 ± 1.2	−48.5 ± 1.6†	−9.5 ± 1.1	−46.1 ± 1.4	−56.4 ± 0.7†	−10.3 ± 1.1
ACh + 4-AP (n = 9, 9)	−27.1 ± 1.1§	−37.8 ± 1.1†§	−7.9 ± 0.9	−33.8 ± 2.1§	−40.5 ± 2.1†§	−6.5 ± 1.1§
ACh + 4-AP and 18βGA (n = 4, 4)	−39.0 ± 2.1¶	−52.0 ± 1.8†	−12.3 ± 1.0¶	35.3±2.0	−47.5±1.9†¶	−12.3 ± 1.6¶

^*Impalements maintained during 4-AP application in the absence and presence of l-NNA.

^†Significantly different from value of membrane potential in the absence of ACh (P < 0.01).

^‡Significantly different from change in membrane potential due to ACh in the absence of L-NNA (P < 0.01).

^§Significantly different from value in the absence of 4-AP (P < 0.01).

^¶Significantly different from value in the presence of 4-AP (P < 0.01).