Figure 3.

G. sulphuraria 12-d cells were sensitive to the addition of solutions to the culture medium. In vitro PIP₂ formation (A) and IP₃ levels (B) were measured in nontreated cells (□), in cells treated with conditioned medium (○), and in cells osmostimulated by 25 mm KCl in conditioned medium (▵). Conditioned medium did not affect PIP₂ formation in microsomes from d-7 cells (data not shown). Values are the averages of duplicate assays from a representative experiment. Vertical bars indicate the duplicate range. The experiments were repeated twice and the trends were similar.