Table 1

Electrophysiological parameters of HT29cl.19A cells before and after application of histamine

Vt (mV)Rt (Ω×cm2)Va (mV)fRaIsc (μA/cm2)
TNF-α, tumour necrosis factor α; Vt, transepithelial potential; Va, intracellular potential; Isc, short circuit current; Rt, transepithelial resistance; fRa, fractional resistance.
Effects of addition of 100 μM histamine to the serosal side of the cells. ΔHistamine represents the difference between phase 2 and baseline.
n=5 for control experiments; n=7 for TNF-α exposed monolayers except for Va and fRa (n=5).
Mean incubation time for TNFα (10 ng/ml) was 6–24 hours.
Statistical significance was evaluated using the Students t test: **p<0.01 compared with control histamine. 

Control
    Baseline1.7 (0.7)195 (10)−62 (6) 0.67 (0.02) 9.5 (5)
    Histamine phase 11.6 (0.7)195 (10)−58 (3) 0.73 (0.05) 8.9 (5)
    Histamine phase 22.5 (0.8)190 (11)−66 (7) 0.65 (0.02)14 (6)
    ΔHistamine0.8 (0.1) −5 (2) −4 (0.4)−0.02 (0.01) 5 (1)
TNF-α
    Baseline2.2 (0.7)173 (12)−57 (2) 0.70 (0.06)13 (4)
    Histamine phase 12.1 (0.7)173 (12)−54 (3) 0.73 (0.05)12 (4)
    Histamine phase 28.4 (1)**154 (11)**−38 (2)** 0.47 (0.07)**58 (11)**
    ΔHistamine6.2 (0.8)**−20 (5)** 19 (3)**−0.24 (0.05)**45 (10)**