Figure 5.

Inhibition of extracellular Ca²⁺ entry influences prolonged 5-HT-mediated Ca²⁺ signaling in single PASMCs. (a) 5-HT (10 μM) -induced cytosolic [Ca²⁺] oscillations. (b) 5-HT (10 μM) -induced elevation in basal cytosolic [Ca²⁺] and [Ca²⁺] oscillations. (c) Effect of Ca²⁺ removal on cytosolic [Ca²⁺] during 10 μM 5-HT. (d) Effect of 10 mM Ni²⁺ on cytosolic [Ca²⁺] during 10 μM 5-HT. (e) Effect of 10 μM nisoldipine on cytosolic [Ca²⁺] during 10 μM 5-HT. (f) Mean change in [Ca²⁺] oscillatory frequency due to 5-HT in the absence or presence of Ca²⁺ influx pathway inhibition. (g) Change in cytosolic [Ca²⁺] during Ca²⁺ influx pathway inhibition in the presence of 5-HT measured relative to the change in cytosolic [Ca²⁺] measured during 5-HT alone. Dashed line represents the basal cytosolic [Ca²⁺]. Error bars represent±s.e.m. Agonists were present at times shown by the bars. Means significantly different from their controls by ^*a two-tailed paired t-test or ^†signed rank test (P<0.05).