Figure 3.

Chelation of extracellular Ca²⁺ indicates S. typhimurium–induced [Ca²⁺] increase results from both intracellular stores and Ca²⁺ influx. Fluorometric assays of intracellular calcium. Intracellular [Ca²⁺] was measured in Fura-2–loaded model intestinal epithelia in response to (a) ionomycin (1 μg/mL), (b) carbachol (100 μM), or (c) S. typhimurium in the presence or absence of EGTA (5 mM), which was added 10 seconds before the addition of an agonist.