Taesotikul T, Panthong A, Kanjanapothi D, Verpoorte R, Scheffer J J
Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Thailand.
J Ethnopharmacol. 1998 Jan;59(3):131-7. doi: 10.1016/s0378-8741(97)00116-5.
The effects of a crude alkaloidal (CA) fraction from the stem of Tabernaemontana pandacaqui Poir. on the blood pressure and heart rate were investigated in conscious as well as anesthetized rats. The CA fraction exerted a hypotensive activity in both experimental models. In pentobarbital anesthetized rats, an intravenous administration of the CA fraction caused two consecutive hypotensive and bradycardiac responses. In order to investigate the mechanism of the responses, the effect of the CA fraction on the blood pressure and the heart rate was tested in various experimental animals such as pithed rats, reserpinized rats under pentobarbital anesthesia and atropine- or chlorpheniramine-treated rats under pentobarbital anesthesia. The results obtained suggest that the hypotensive and bradycardiac responses of the first phase might involve cholinergic and central mechanisms, whereas those of the second phase involve mechanisms which are mediated by central, biogenic amines, acetylcholine and histamine.
对来自长节珠（Tabernaemontana pandacaqui Poir.）茎的粗生物碱（CA）组分对清醒和麻醉大鼠的血压及心率的影响进行了研究。CA组分在两种实验模型中均表现出降压活性。在戊巴比妥麻醉的大鼠中，静脉注射CA组分引起了连续两次的降压和心动过缓反应。为了研究这些反应的机制，在各种实验动物中测试了CA组分对血压和心率的影响，如脊髓横断大鼠、戊巴比妥麻醉下的利血平化大鼠以及戊巴比妥麻醉下经阿托品或氯苯那敏处理的大鼠。所得结果表明，第一阶段的降压和心动过缓反应可能涉及胆碱能和中枢机制，而第二阶段的反应则涉及由中枢、生物胺、乙酰胆碱和组胺介导的机制。
