摘要
THP和Ver均能对抗CaCl_2所致离体豚鼠右房正性频率作用,非竞争性拮抗CaCl_2左房正性肌力作用以及Iso右房正性频率和左房正性肌力作用。THP和Ver浓度依赖性和频率依赖性地抑制左房收缩中的阶梯现象,使正阶梯翻转为负阶梯。而对休息后加强影响较小。结果提示THP对心房的抑制作用与Ver相似,与拮抗Ca^(2+)有关,可能主要通过抑制心肌细胞外Ca^(2+)内流所致。
L-tetrahydropalmatine (THP) & verapamil ( Ver ) antagonized CaCl2-induced positive chronotropic response in spontaneously beating right atria of guinea pig, and noncompetitively antagonized CaCl2 -& isoprenaline ( Iso ) -induced positive inotropic effects of the left atria electrically driven at 1.5 Hz & Iso-induced positive chronotro-pic effects of the right atria. THP & Ver had dose-dependent & frequency-dependent inhibitory effects on contraction of the left atria, and inversed the frequency-contraction ...
出处
《中国药理学通报》
CAS
CSCD
北大核心
1989年第3期158-161,共4页
Chinese Pharmacological Bulletin
