Jakobsen J, Schmidt J F, Waldemar G, Paulson O B
Department of Neurology, Rigshospitalet, Copenhagen, Denmark.
J Cardiovasc Pharmacol. 1990 Apr;15(4):574-8. doi: 10.1097/00005344-199004000-00008.
The antihypertensive agent dilevalol, a stereoisomer of labetalol, causes vasodilatation by combined beta-adrenergic blockade and direct beta 2-receptor agonism. The acute effect of a single oral dose of 400 mg dilevalol on cerebral blood flow (CBF), and its response to induced changes in arterial carbon dioxide tension (PaCO2), and the cerebral metabolic rate of oxygen (CMRO2) were studied after 1, 2, and 4 h in eight normotensive volunteers. Serum dilevalol 2 h after oral intake ranged between 22 and 49 ng/ml. Mean arterial blood pressure was reduced from 93 +/- 8 to 86 +/- 8 mm Hg (p less than 0.01). An analysis of variance of the successive differences of CBF during the study showed that dilevalol altered CBF significantly. After 1 h CBF had decreased by 4.4% (p less than 0.05), whereas the 2 and 4 h values were similar to the pretreatment level. CMRO2 showed a tendency for reduction (p = 0.086). The CBF response to changes in PaCO2 remained unchanged. It is concluded that a single dose of dilevalol induces a slight and short-lasting decrease in CBF, probably due to a direct effect on brain metabolism.
抗高血压药地来洛尔是拉贝洛尔的一种立体异构体，它通过联合β-肾上腺素能阻滞和直接的β2受体激动作用引起血管舒张。在8名血压正常的志愿者中，研究了单次口服400 mg地来洛尔1、2和4小时后对脑血流量（CBF）的急性影响，以及其对动脉血二氧化碳分压（PaCO2）诱导变化的反应和脑氧代谢率（CMRO2）。口服后2小时血清地来洛尔浓度在22至49 ng/ml之间。平均动脉血压从93±8降至86±8 mmHg（p<0.01）。研究期间对CBF连续差值的方差分析表明，地来洛尔显著改变了CBF。1小时后CBF下降了4.4%（p<0.05），而2小时和4小时的值与预处理水平相似。CMRO2有下降趋势（p = 0.086）。CBF对PaCO2变化的反应保持不变。结论是，单次剂量的地来洛尔可引起CBF轻微且短暂的下降，可能是由于对脑代谢的直接作用。
