Intracarotid verapamil decreases both proximal and distal human cerebrovascular resistance.
Intracarotid verapamil decreases both proximal and distal human cerebrovascular resistance.
复制标题
颈动脉内注射维拉帕米可降低近端和远端人脑血管阻力。
DOI：
10.1097/00000542-200404000-00005
复制
发表时间：
2004
期刊：
影响因子：
8.8
通讯作者：
Sahlein,DanielH
中科院分区：
文献类型：
--
作者：
Joshi,Shailendra;Meyers,PhilipM;Pile-Spellman,John;Wang,Mei;Sahlein,DanielH
研究背景：作者使用一种测量近端和远端脑血管阻力的新方法，确定了颈内动脉注射维拉帕米对受试者的节段性效应。他们的假设是，颈动脉内注射钙通道阻滞剂维拉帕米，可以增加脑血流量，逆转动脉痉挛，同时降低近端电导和远端小动脉阻力。方法在脑血管造影术中，同轴导管经股动脉漂浮到颈内和大脑中动脉。记录股动脉、颈内动脉和大脑中动脉的压力。采用颈动脉Xe注射技术测量大脑半球血流量。测量近端和远端动脉的脑血管阻力。颈动脉内注入生理盐水和维拉帕米(1 mg/min)5min，记录脑血流量和血流动力学数据。结果颈内动脉内维拉帕米使133Xe脑血流量由43+/-11增至59+/-11ml·100g(-1)。Min(-1)(P=0.001；n=9)。近端和远端动脉的脑血管阻力分别从0.17±0.95降至0.12±0.75和1.63+/-0.78降至1.03+/-0.33 mm Hg。Ml(-1)。100g(-1)。Min(-1)(P<；0.01)。计算的近端传导阻力和远端小动脉(软膜加实质)阻力显示出类似的下降。经颅多普勒测量(n=5)低估了颈动脉内注射维拉帕米的效果，这与大脑中动脉直径的增加一致。结论颈动脉内注射维拉帕米同时降低了近端小动脉电导和远端小动脉阻力。此外，通过测量大脑动脉内压力梯度的变化和同时测量Xe脑血流来研究药物在人体内的节段性效应是可行的。
BackgroundThe authors determined the segmental effects of intracarotid verapamil in human subjects by using a novel method of measuring proximal and distal cerebrovascular resistance. Their hypothesis was that intracarotid verapamil, a calcium channel-blocking drug that augments cerebral blood flow and reverses arterial spasm, would decrease both the proximal-conductance and the distal-arteriolar resistance.MethodsCoaxial catheters were transfemorally floated into internal carotid and middle cerebral arteries during cerebral angiography. Pressures were recorded in the femoral, internal carotid, and middle cerebral arteries. Hemispheric cerebral blood flow was measured by the intracarotid Xe injection technique. Cerebrovascular resistance was measured for the proximal and distal arteries. Cerebral blood flow and hemodynamic data were recorded during intracarotid infusion of saline and verapamil (1 mg/min) for 5 min. Transcranial Doppler blood flow velocity in the middle cerebral artery was also recorded.ResultsIntracarotid verapamil increased in 133Xe cerebral blood flow from 43+/-11 to 59+/-11 ml. 100 g (-1). min (-1)(P= 0.001; n= 9). The cerebrovascular resistance measured for the proximal and distal arteries decreased from 0.17+/-0.95 to 0.12+/-0.75 and from 1.63+/-0.78 to 1.03+/-0.33 mmHg. ml (-1). 100 g (-1). min (-1)(P< 0.01), respectively. The calculated proximal-conductive and distal-arteriolar (pial plus parenchymal) resistances showed a similar decrease. Transcranial Doppler measurements (n= 5) underestimated the effects of intracarotid verapamil that were consistent with an increase in middle cerebral artery diameter.ConclusionsIntracarotid verapamil decreases both the proximal-conductance and the distal-arteriolar resistance. Furthermore, it is feasible to investigate segmental effects of drugs in human subjects by measuring changes in pressure gradients within the cerebral arteries and simultaneous Xe cerebral blood flow measurements.