− E Cl [1] E Cl − E Cl − − [1–3] [1–3] I Cl,cAMP [4–6] − I Cl,Swell [7–9] 2+ − I Cl,Ca [10–12] I AB [13,14] I AB − ( NO 3   - > I − > Cl - ) − 2+ [13,14] I AB [14] I AB [13] [15,16] I AB I AB I ANION I ANION I AB [13,14] [17] Methods Atrial myocyte isolation Table 1 2 Table 1 2 2 Electrophysiology Solutions used. I AB [14] Table 1 Table 1 Table 1 N d N Drugs. N Electrophysiological recording −1 + 2+ Recordings were made using an Axopatch 200A amplifier, and data were recorded on computer using pClamp v. 9.0 software (Axon Instruments, Forster City, CA). Data were analyzed using the Clampfit program of pClamp v. 9.0. NO 3   - t NO 3   - p Human atrial action potential simulations [18] I ANION NO 3   - − Figs. 1 and 2 [18] I ANION (1) I ANION = g ANION ( V - E ANION ) 1 - c × e ( d × ( V - E ANION ) ) E ANION g ANION I ANION (1) Fig. 1 Fig. 2 g ANION E ANION c d −4 −1 NO 3   - I ANION g ANION c d −4 −1 − I ANION Results and discussion I AB [14] Fig. 1 Fig. 1 − − NO 3   - − − NO 3   - − − Fig. 1 − − NO 3   - − − Fig. 1 NO 3   - − − I ANION I AB I AB NO 3   - NO 3   - > I - > Cl - [13,14] Fig. 2 I ANION NO 3   - I ANION NO 3   - − E rev I ANION E rev I Cl, Swell [15,17,19–21] I ANION I Cl,Swell − NO 3   - [14] Fig. 2 I ANION I V Fig. 2 I ANION I Cl,Swell I ANION Fig. 2 NO 3   - I ANION I Cl,Swell [19,21] I AB [14] I ANION I ANION − − NO 3   - I ANION I AB [13,14] I ANION I Cl,Swell [1] [17] p I ANION − I ANION 50 [22] 50 [22] I Ca,cAMP [1,15,19–21,23] [15,19–21] I Cl,Ca [24] Table 1 2+ 2+ i I ANION I AB [13,14] I ANION Fig. 3 [18] I ANION Fig. 3 NO 3   - − I ANION 50 50 I ANION 3 I ANION 90 90 I ANION − I ANION NO 3   - I ANION I ANION I Ca,L I Ca,L I ANION I ANION I Ca,L 50 Fig. 3 I ANION I ANION