Haller H, Lenz T, Oelkers W, Luft F C, Distler A
Department of Internal Medicine, University Hospital-Steglitz, Germany.
J Hum Hypertens. 1994 Aug;8(8):551-4.
A remarkably close correlation between platelet cytosolic calcium ([Ca2+i]) and arterial blood pressure has been identified in patients with essential hypertension. We tested the notion that a pharmacologically relevant infusion of angiotensin (Ang) II is associated with an increase in cytosolic calcium [Ca+2i]. Five normal volunteers received Ang II (5 ng/kg/min) for three hours or vehicle intravenously in random sequence respectively. The investigations were conducted at least 14 days apart. Plasma renin activity and blood pressure were measured every 20 minutes. [Ca+2i] was measured with the fluorescent indicator fura-2 before and at the end of the last hour of Ang II infusion. Mean arterial blood pressure increased by 10 mmHg during Ang II infusion (P < 0.05). Plasma renin activity decreased from 2.21 +/- 0.28 to 1.31 +/- 0.22 ng/ml/hour during the Ang II infusion (P < 0.05). On the other hand, [Ca+2i] was 131 +/- 13 nmol/l before and 129 +/- 13 nmol/l after the infusion (P = NS). The data suggest that agonists may increase blood pressure without an increase in platelet [Ca+2i]. Furthermore, Ang II may increase blood pressure independently of [Ca+2i].
在原发性高血压患者中，已发现血小板胞质钙（[Ca2+i]）与动脉血压之间存在显著的密切相关性。我们检验了以下观点：药理学相关剂量的血管紧张素（Ang）II输注与胞质钙[Ca+2i]升高有关。五名正常志愿者分别随机接受Ang II（5 ng/kg/分钟）静脉输注三小时或输注溶媒，两次研究至少间隔14天。每20分钟测量一次血浆肾素活性和血压。在Ang II输注的最后一小时开始时和结束时，用荧光指示剂fura-2测量[Ca+2i]。在Ang II输注期间，平均动脉血压升高了10 mmHg（P < 0.05）。在Ang II输注期间，血浆肾素活性从2.21±0.28降至1.31±0.22 ng/ml/小时（P < 0.05）。另一方面，输注前[Ca+2i]为131±13 nmol/l，输注后为129±13 nmol/l（P = 无显著性差异）。数据表明，激动剂可能在不增加血小板[Ca+2i]的情况下升高血压。此外，Ang II可能独立于[Ca+2i]升高血压。
