【摘要】 应用血管平滑肌等张收缩和放射免疫测定环核苷酸水平等方法研究了普鲁托品 ( Pro)的扩血管作用及其机理 .结果表明 ,Pro浓度依赖性地松弛去氧肾上腺素 ( PE,1 μmol· L-1)和 KCl( 30 mmol·L-1)预收缩的兔胸主动脉螺旋条 ,EC50 分别为 ( 37± 2 0 )和 ( 4 0± 1 1 ) μmol·L-1.Pro30 μmol·L-1使PE和 KCl收缩兔胸主动脉的量效曲线非平行右移 ,最大反应压低 ,p D2 ′分别为 4.0 7± 0 .1 7和 3.86± 0 .1 8.格列本脲 ,N- L-硝基精氨酸 ,普萘洛尔和吲哚美辛不影响 Pro的舒血管作用 .Pro1 0和 1 0 0μmol· L-1显著增加兔胸主动脉血管平滑肌内c AMP和 c GMP水平 .结果提示 ,Pro的扩血管作用可能与增高平滑肌细胞内 c AMP和 c GMP水平有关 .更多还原

【Abstract】 The vasodilative mechanism of protopine(Pro) in isolated rabbit aorta was studied by recording the isotonic contraction and radioimmunoassaying the levels of cyclic nucleotides. Pro induced a relaxation with a concentration dependent manner in the isolated strips of rabbit aorta precontracted by phenylephrine (PE, 1 μmol·L -1 ) and KCl(30 mmol·L -1 ), the EC 50 was (37±20) and (40±11) μmol·L -1 , respectively (P>0.05). Furthermore, the concentration response curves of PE and KCl were shifted to right nonparallelly, and the maximum responses were decreased in the presence of Pro(30 μmol·L -1 ). The pD 2′ was 4.07±0.17 and 3.86±0.18, respectively. The relaxing effect of Pro on the strip of rabbit aorta precontracted by PE was not affected by glibenclamide, N L nitro arginine, indometacin and propranolol. Pro 10 and 100 μmol·L -1 increased the levels of cAMP and cGMP significantly. The results suggest that the vasodilative mechanism of Pro be related to the intracellular elevation of cAMP and cGMP.更多还原