论文部分内容阅读
四氢小蘖碱(THB)3～300μmol/L呈浓度依赖性地减慢离体心房自动收缩频率(P<0.05或P<0.01)。1C_(50)值为19.44μmol/L,300μmol/L可使右房率降低61.3%。THB3、10和30μmol/L可抑制CaCl_2的正性变时作用时间效应。并呈剂量依赖性(P<0.05或P<0.01),THB10和30μmol/L可拮抗ISO诱发的心房率加快,使量—效曲线非平行右移,最大反应压低。表现为非竞争性拮抗作用。非竞争性拮抗剂与受体的亲和力的PD_2值为5.32。结果表明THB负性变时作用可能与阻滞Ca~(2+)内流有关。
The concentration of tetrahydrobiopterine (THB) 3 ~ 300μmol / L slowed the atrial contraction frequency in vitro (P <0.05 or P <0.01) in a concentration - dependent manner. 1C_ (50) value of 19.44μmol / L, 300μmol / L can reduce the right atrial rate of 61.3%. THB3, 10 and 30 μmol / L inhibited the positive chronotropic effect of CaCl2. (P <0.05 or P <0.01). The rates of atrial fibrillation induced by ISO at 30 and 30 μmol / L could be accelerated by THB 10 and 30 μmol / L, respectively. The performance of non-competitive antagonism. The PD2 value of the affinity of the noncompetitive antagonist to the receptor was 5.32. The results showed that the negative effect of THB may be related to the block of Ca ~ (2+) influx.