Kingma R, Scheffer G J, TenVoorde B J, Wesseling K H, de Lange J J
Department of Anesthesiology, Vrije Universiteit Amsterdam, The Netherlands.
J Cardiovasc Pharmacol. 1995 Sep;26(3):445-52. doi: 10.1097/00005344-199509000-00015.
Ketanserin is an antihypertensive drug with affinity to both serotonin S2- and alpha 1-adrenoceptors. The specific effects of ketanserin on the baroreflex are not fully understood. We, therefore, studied baroreflex regulation based on blood pressure (BP) and heart rate (HR) responses to several maneuvers before and after the administration of 2 x 5 mg of ketanserin i.v. both in supine and in standing posture. Seven young healthy volunteers were investigated. We measured spontaneous variability in HR and BP (Finapres), and performed deep inspiration, Valsalva, and lying-to-standing tests. We also used a modified Valsalva maneuver that consist of Deep Inspiration Breath-holding with closed glottis and EXpiration: DIBEX maneuver. From the BP recordings, peripheral resistance (TPR) and stroke volume (SV) were estimated by the Modelflow method. Thirty minutes after the administration of ketanserin, there was no significant change in mean HR, BP, spectral power of HR and BP variability, baroreflex sensitivity, or Valsalva ratio. Thus ketanserin did not affect the cardiac baroreflex mechanism. However, in standing position, SV increased and TPR decreased under the influence of ketanserin, and BP overshoot after the Valsalva and DIBEX maneuver was significantly decreased as well. There was also no reflex recovery of BP during the DIBEX maneuver in three volunteers, who felt faint. These observations indicate that there is a lack of vasoconstriction. We conclude that ketanserin is not a vasodilator but seems to inhibit vasoconstriction.
酮色林是一种对5-羟色胺S2受体和α1肾上腺素受体均有亲和力的抗高血压药物。酮色林对压力反射的具体作用尚未完全明确。因此，我们在静脉注射2×5mg酮色林前后，分别在仰卧位和站立位，基于血压（BP）和心率（HR）对几种动作的反应，研究了压力反射调节。对7名年轻健康志愿者进行了调查。我们测量了HR和BP的自发变异性（Finapres），并进行了深吸气、瓦尔萨尔瓦动作以及卧立位试验。我们还使用了一种改良的瓦尔萨尔瓦动作，即屏气深吸气并声门关闭然后呼气：DIBEX动作。根据血压记录，采用模型流量法估算外周阻力（TPR）和每搏输出量（SV）。注射酮色林30分钟后，平均HR、BP、HR和BP变异性的频谱功率、压力反射敏感性或瓦尔萨尔瓦比值均无显著变化。因此，酮色林不影响心脏压力反射机制。然而，在站立位时，在酮色林的影响下，SV增加而TPR降低，瓦尔萨尔瓦动作和DIBEX动作后的血压过冲也显著降低。在三名感到头晕的志愿者中，DIBEX动作期间也没有血压的反射性恢复。这些观察结果表明存在血管收缩不足。我们得出结论，酮色林不是血管扩张剂，而是似乎抑制血管收缩。
