Fig. 5. Transphosphatidylation of PA by n-butanol inhibits antigen-stimulated Ca²⁺ mobilization in IgE-sensitized and indo-1-loaded RBL cells. (A) Ca²⁺ response of RBL cells in the presence of extracellular Ca²⁺: control cells (first trace), cells pretreated with 0.5% (v/v) n-butanol for 2 minutes (second trace), or pretreated with 0.5% (v/v) t-butanol for 2 minutes (third trace). (B) Percent inhibition of Ca²⁺ mobilization in RBL cells by n-butanol (dark bars) and t-butanol (open bars), in the presence and absence of extracellular Ca²⁺. IgE-sensitized and indo-1-loaded cells were evaluated for antigen-stimulated Ca²⁺ response with or without butanol treatment, and percent inhibition calculated according to Eqn 2. Results shown are averages of three experiments and bars show s.e.m.