Hypotensive Activity of Tetrandrine in Rats
Hypotensive Activity of Tetrandrine in Rats
复制标题
粉防己碱对大鼠的降压活性
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
P. A. Zwieten
中科院分区：
文献类型：
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作者：
J. Qian;M. Thoolen;J. C. A. Meel;P. Timmermans;P. A. Zwieten
本文观察了粉防己碱对戊巴比妥钠麻醉清醒的正常血压和高血压大鼠（SH大鼠、肾性高血压大鼠、DOCA盐性高血压大鼠）动脉压和心率的影响。粉防己碱静脉内（i. v.）对这些动物造成急性、持久和剂量依赖性的平均动脉压降低。心率没有明显改变。预先动脉注射粉防己碱15分钟可抑制高选择性α2肾上腺素能受体激动剂B-HT 920引起的大鼠舒张压升高，并呈剂量依赖性。在低剂量下，观察到向右平行位移，而在较高剂量下，位移是非平行的。高剂量汉防己甲素使α肾上腺素受体激动剂甲氧胺的升压反应曲线仅轻微右移，而不抑制最大反应。粉防己碱还引起静脉注射加压素的血管加压效应曲线的中度漂移。粉防己碱仅对大鼠脑细胞膜上[3 H]-哌唑嗪（α1-肾上腺素受体）和[3 H]-可乐定（α1-肾上腺素受体）的特异性结合位点显示出较小的亲和力。结果提示，粉防己碱的降压作用可能与抑制血管突触后α_2肾上腺素能受体介导的缩血管张力有关。
The influence of tetrandrine on arterial pressure and heart rate of pentobarbitone-anaesthetized and conscious normotensive and hypertensive rats (SH rats, renal hypertensive rats, DOCA-salt hypertensive rats) was investigated. Tetrandrine administered intravenously (i.v.) to these animals caused an acute, long-lasting and dose-dependent decrease in mean arterial pressure. Heart rate was not significantly altered. In pithed rats, tetrandrine injected intraarterially 15 min previously impaired the increase in diastolic pressure induced by i.v. B-HT 920, a highly selective α2-adrenoceptor-stimulating agent, in a dose-dependent manner. In a low dose, a parallel displacement to the right was observed, whereas for higher doses the shift was non-parallel. A high dose of tetrandrine shifted the pressor response curve of the αpadrenoceptor agonist, methoxamine, only slightly to the right and did not depress the maximal response. Tetrandrine also caused a moderate rightward shift of the vasopressor effect curve of vasopressin applied i.v. Tetrandrine displayed only minor affinities for specific binding sites in rat brain membranes for [3H]-prazosin (α1-adrenoceptors) and for [3H]-clonidine (α1-adrenoceptors). The results obtained suggest that the hypotensive effect of tetrandrine may be related to an impairment of vasoconstrictor tone mediated by vascular postsynaptic α2-adrenoceptors.