Chloroform Extract of Artemisia annua L. Relaxes Mouse Airway Smooth Muscle

Figure 5

CEAA blocks ACh-elicited Ca²⁺ influx. (a) ACh induced contractions in TRs, which were inhibited in part by nifedipine, and the remaining contraction was inhibited by CEAA. (b) ACh induced a rapid and transient contraction under Ca²⁺-free conditions (0 Ca²⁺ and 0.5 mM EGTA); following the addition of 2 mM Ca²⁺, a strong sustained contraction occurred. (c) A set of experiments was performed in the presence of nifedipine (). Compared with (b), nifedipine had no effect on the transient contraction under 0 Ca²⁺ conditions but significantly decreased the sustained contraction under 2 mM Ca²⁺ conditions. (d) A set of experiments was conducted in the presence of CEAA (). Under Ca²⁺-free conditions (0 Ca²⁺ and 0.5 mM EGTA); ACh induced a smaller transient contraction than that with no CEAA. Following the addition of 2 mM Ca²⁺, only a very weak contraction occurred.

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(b)

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