EFFECT OF L-THP ON CONTRACTION OF ISOLATION GUINEA PIG TRACHEA INDUCED BY SEVERAL AGONISTS / 中国药理学通报

ABSTRACT

The antagonistic effects of L-THP, Ver and Pap to contraction of isolated guinea pig trachea preparations induced by BaCl2 10-3mol/L ,KC1 3?10-2mol/L, 5-HT 2?10-5mol/L, Ach 2?10-5mol/L and His 2? 10-5mol/L were studied.The antagonistic effects of L-THP were different from Ver and Pap. The IC50 value of L-THP for contraction induced by BaCl2, KC1, 5-HT and His was 3 .5? 10-5mol/L , 4.5 ? 10-5mol/L , 2.5?10-3 mol/L and 8.9? 10-5mol/L respectively. It was showed that sensibility of several agonists to inhibition by L-THP was correlated with dependence of extracellular Ca2+. The potencies of L-THP on anti-KCl and anti-5-HT actions were similar. The results suggested that LTHP possesses anti-calcium and anti-5-HT action on guinea pig trachea.