Figure 3

Comparison of effects of active linaclotide and lubiprostone on T84 cell homeostasis: (A) Δ[cGMP] _i ; (B) Δ[Ca²⁺] _i ; (C) Δplasma membrane potential. 200 nM active linaclotide and 100 nM lubiprostone were used. Data is plotted as mean ± S.E. (A) Δ[cGMP]_i: n = 5, p < 0.0005 lin vs lubi. 1 μM NaNP was the positive control. Basal [cGMP]_is =1.7 ± 0.001, 3.1 ± 0.01 and 23.9 ± 0.002 pmol/10⁵T84 cells for lin, lubi and PGE₁ respectively. (B) Δ[Ca²⁺]_i: n = 3, *p < 0.01, **p < 0.0005, #p < 0.02, ##p < 0.0025, xp < 0.001 all wrt 1 nM drug. Basal [Ca²⁺]_is = 175.5 ± 7.1, 117.6 ± 6.4 and 80.8 ± 2.4 nM for lin, lubi and PGE₁ respectively. (C) Δplasma membrane potential: n = 5, ##p < 0.001, *p < 0.02 all wrt 1 nM drug. PGE₁ was used as positive control.