Figure 4. Effects of PGF_2α on NAd-induced contractions in CCSM.

In a spontaneously active CCSM preparation, NAd (0.3 μm) initiated sustained contractions (Aa). In the same preparation, PGF_2α (0.1 μm) caused sustained contractions, and a subsequent application of NAd (0.3 μm) initiated larger contractions than those in control conditions (Ab and c). In another preparation, which had been exposed to nicardipine (1 μm), NAd (0.3 μm) initiated sustained contractions (Ba). PGF_2α (0.1 μm) caused a small sustained contraction, and a subsequent application of NAd (0.3 μm) initiated a larger contraction than that in control conditions (Bb and c). The scale bar on the right of Bb applies to all traces.