Figure 4. .

Effect of chelation of extracellular Ca²⁺ on VIP-stimulated ERK1/2 activity. Cultured rat goblet cells were preincubated in either Ca²⁺ free, KRB containing 2 mM EGTA, or normal Ca²⁺ containing KRB for 5 minutes prior to addition of VIP 10⁻⁸ M for 5 minutes. Blot shown in (A) is representative of four individual animals. Please note that lanes in blot are from the same experiment but have been rearranged for clarity. Data shown in (B) are mean ± SEM from four individual experiments. *Indicates significant difference from basal. #Indicates significance from VIP.