Effects of oral administration of synthetic tetrandrine (TD) derivatives (20 mg/kg per day) for 9 weeks on blood pressure, heart rate, plasma renin concentration (PRC) and vascular reactivities to pressor substances were studied in spontaneously hypertensive (SHR) rats. 2. 7-O-Ethyl fangchinolin (7-O-EFC) and 7-O-isopropyl fangchinolin (7-O-IFC) produced a significant and sustained reduction in blood pressure from the first week of administration. 7-O-EFC reduced heart rate when determined under restraint conditions, but not under unanesthetized, freely moving conditions. 3. TD derivatives produced no effect on PRC. 4. Pressor response to phenylephrine was reduced significantly whereas the response to angiotensin II was enhanced after prolonged administration of 7-O-EFC and 7-O-IFC. 5. These results demonstrate that TD derivatives are potential antihypertensive drugs, and that attenuation of the pressor response to phenylephrine may contribute at least in part to its antihypertensive effect.
摘要
研究了给自发性高血压（SHR）大鼠口服合成粉防己碱（TD）衍生物（每天20毫克/千克）9周对血压、心率、血浆肾素浓度（PRC）以及血管对升压物质反应性的影响。2. 7 - O - 乙基防己诺林碱（7 - O - EFC）和7 - O - 异丙基防己诺林碱（7 - O - IFC）从给药第一周起就使血压显著且持续降低。在束缚条件下测定时，7 - O - EFC可降低心率，但在未麻醉、自由活动条件下则不然。3. TD衍生物对PRC无影响。4. 长期给予7 - O - EFC和7 - O - IFC后，对去氧肾上腺素的升压反应显著降低，而对血管紧张素II的反应增强。5. 这些结果表明，TD衍生物是潜在的抗高血压药物，对去氧肾上腺素升压反应的减弱可能至少部分促成了其抗高血压作用。
