Fig. 1.
Illustration of the experimental setup for simultaneous monitoring of muscle contraction/relaxation by sonomicrometry [as change (Δ) in intracrystal distance (ICD)] and Cl− secretion in Ussing flux chambers [as change in short-circuit current (Isc)]. The traces were recorded and stored on the data-acquisition computer, and 1-mm piezoelectric crystals were glued in the circular direction of the whole-thickness flat sheets of colon at a distance of 4–5 mm apart. ΔICD was measured in μm distance between the piezoelectric crystals. A shorter distance between crystals indicates contraction and a larger distance relaxation. Drugs can be added to either serosal or mucosal compartments. Aperture area of the Ussing chamber = 0.785 cm2. ΔIsc was measured in μA/0.785 cm2 and then normalized to an area of 1 cm2. Details are described in methods.