Fig. 2.

Time course of serosal amino acid (AA) accumulation by rat cecum. A: cecum was incubated in an Ussing chamber with luminal Parson’s solution containing 14 AAs (as designated in the figure key), all at 0.5 mM, and serosal Parson’s solution. Every 15 min, the entire serosal bath was collected and replaced. Samples were analyzed by ultra-performance liquid chromatography-mass spectrometry. B: replicate experiment with an otherwise identical Na⁺-free (K⁺ replacement) luminal solution. Each plot is representative of several time course experiments.