FIG 4.

Gd³⁺ inhibits cell volume recovery from swelling and rescue by βγ-imidoATP during apyrase-induced swelling. (A) Representative LS experiment showing cell size changes in suspensions of wild-type Dictyostelium amoebas immediately after exposure to hypotonic challenge in the presence (+ Gd³⁺) or absence (control) of Gd³⁺ (100 μM). (B) Representative plot showing extracellular ATP concentrations with time. (C) Mean peak extracellular ATP concentrations measured under hypotonic conditions in the absence or presence of Gd³⁺ (100 μM) (n = 5). (D and E) Representative trace (D) and mean peak cell size (E) showing cell changes under hypotonic conditions. The cells were exposed to apyrase (2 U/ml) and βγ-imidoATP (100 μM) and to Gd³⁺ (100 μM) where indicated. The control values are from cells exposed to treatment (n = 5). *, P < 0.05. The error bars indicate standard errors of the means.