Ca²⁺ oscillations, Ca²⁺ sensitization, and contraction activated by protein kinase C in small airway smooth muscle

Video 1.
Contractile response of a small airway in a mouse lung slice induced by stimulation with 5-HT, KCl, and PMA. This time-lapse video shows the responses of small airway to stimulation with 1 µM 5-HT, 50 mM KCl, and 10 µM PMA, as shown in the experiment illustrated in Fig. 1. Strong and sustained airway contraction was induced by superfusion of lung slices with 5-HT (present only when label is present). The airway relaxed after 5-HT withdrawal and washout of the lung slice with sHBSS. In contrast, both KCl and PMA induced transient and unsynchronized contractions of SMCs in the airway lumen wall (SMC twitching) and a small reduction in total luminal area. Experimental time is indicated (top label) in the format hours:minutes.