ABSTRACT
Objective: To investigate the effect of n-butanol fraction from Elaeagnus pungens leaves (BFEP) on the contraction of isolated guinea pig tracheal smooth muscle under the basal tonus or spasmogens. Methods: Guinea pig tracheal smooth muscle spiral strips were isolated. Under the normal state or the condition treated with acetylchohne (Ach), histamine (Hist), or KCl, Ca2+ release in cells without calcium, and extracellular Ca2+ influx at the high concentration of Ca2+, the effect of BFEP on the tension of isolated trachea was observed. Results: BFEP relaxed the tracheal strip significantly in the concentration-dependent manner under the basal tonus. The tested drug produced an unparallel rightward shift of the cumulative concentration-response curve of Hist or Ach. The contraction induced by high K+ and extracellular Ca2+ influx was inhibited. Conclusion: BFEP could inhibit the contraction of isolated guinea pig tracheal smooth muscle under the basal tonus or spasmogens.