Movie 5.

Xylazine and U-50488 act directly on epithelial cells to cause contraction. MDCK cells were expanded to the point that they formed small multicellular clusters, stained with calcein AM and treated with xylazine (5 mg/mL final), clonidine (5 mg/mL final), U-50488 (1 mM final), or an equal volume of water as a control. Note the rapid cell cluster contraction that occurs following treatment with xylazine and U-50488 but not clonidine or water. Time in mm:ss, scale bars = 100 μm.