Table 1.

Unidirectional ³⁶Cl fluxes across Calu-3 cell monolayers

	Jsm	Jms	Jnet	Ieq	Rt	Vt
Control	1.10 ± 0.12	0.53 ± 0.11	0.58 ± 0.06	0.81 ± 0.06	375 ± 47	−8.14 ± 0.68
Forskolin (10 μmol l−1)	3.13 ± 0.13***	1.63 ± 0.15***	1.51 ± 0.02***	2.75 ± 0.13***	289 ± 30	−21.31 ± 0.97***
Bumetanide (20 μmol l−1)	1.95 ± 0.08+++	1.22 ± 0.06++	0.73 ± 0.05+++	2.15 ± 0.10+++	301 ± 32	−17.35 ± 0.64+++

Experiments were performed under open-circuit, pH-stat conditions (i.e. basolateral 25 mm HCO₃⁻, apical 0 mm HCO₃⁻). The apical solution was stirred with 100% O₂ and buffered at pH 7.4 using 10 mmol l⁻¹ tricine. Forskolin was added to both sides. Bumetanide was added basolaterally. J_sm (serosal-to-mucosal ³⁶Cl⁻ flux), J_ms (mucosal-to-serosal ³⁶Cl⁻ flux), J_net (net ³⁶Cl⁻ flux), I_eq (equivalent short-circuit current) have units of μeq cm⁻² h⁻¹. R_t (transepithelial resistance) has units of Ohms cm² electrical resistance, no time units. Values are mean ± SEM, n= 4 (³⁶Cl⁻ fluxes) or 8 (I_eq, R_t and V_t). ***P < 0.001, forskolin vs. control; ⁺⁺⁺P < 0.001; ⁺⁺P < 0.01, bumetanide vs. forskolin.