Schmidt J F, Waldemar G, Paulson O B
University Clinic of Neurology, Rigshospitalet, Copenhagen, Denmark.
J Cardiovasc Pharmacol. 1990 Dec;16(6):1007-10. doi: 10.1097/00005344-199012000-00022.
The present study was undertaken to examine the effect of captopril on cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2) and CO2 reactivity in eight young healthy volunteers. The mean arterial blood pressure (MABP) was measured intraarterially, and CBF was measured by inhaled xenon-1233. The CO2 reactivity was defined as the relative change in CBF per 0.1 kPa change in arterial CO2. During the CO2 reactivity tests, the CBF changes were estimated by the arteriovenous-oxygen-difference method (CBFsat). Median CBF was 52 ml/100 g/min (50-56) and without any significant regional side-to-side asymmetries. No significant change was observed after captopril. The median resting MABP was 90 mm Hg (89-93), and was slightly reduced by 5 mm Hg (4-6) 1 h after an oral dose of captopril (50 mg). CMRO2 was 3.7 ml/100 g/min (3.5-3.8) and was unchanged after captopril. For the entire range of PaCO2 the median slope of the ln(CBFsat) versus PaCO2 regression line was 1.4 (1.3-1.6) at baseline compared to 1.4 (1.3-1.7) after captopril (p = 0.23). Considering the PaCO2 values between 4.0 and 6.5, the CO2 reactivity was 2.4%/0.1 kPa (2.1-2.4) at baseline and increased significantly to 2.9%/0.1 kPa (2.1-3.2) after captopril (p less than 0.05). No side effects were observed. The present study shows an overall unchanged CO2 reactivity; however, with an increased CO2 reactivity of the cerebral vessels for small changes in PaCO2 around the resting value of PaCO2 and a maintained coupling of CBF and CMRO2 after peroral captopril.
本研究旨在检测卡托普利对8名年轻健康志愿者脑血流量（CBF）、脑氧代谢率（CMRO2）和二氧化碳反应性的影响。通过动脉内测量平均动脉血压（MABP），并采用吸入氙-1233测量CBF。二氧化碳反应性定义为动脉血二氧化碳每变化0.1 kPa时CBF的相对变化。在二氧化碳反应性测试期间，通过动静脉氧分压差法（CBFsat）评估CBF变化。CBF中位数为52 ml/100 g/min（50 - 56），且无任何明显的区域左右不对称。服用卡托普利后未观察到显著变化。静息MABP中位数为90 mmHg（89 - 93），口服一剂卡托普利（50 mg）1小时后轻微降低5 mmHg（4 - 6）。CMRO2为3.7 ml/100 g/min（3.5 - 3.8），服用卡托普利后无变化。对于整个动脉血二氧化碳分压（PaCO2）范围，基线时ln（CBFsat）与PaCO2回归线的中位数斜率为1.4（1.3 - 1.6），服用卡托普利后为1.4（1.3 - 1.7）（p = 0.23）。考虑PaCO2值在4.0至6.5之间，基线时二氧化碳反应性为2.4%/0.1 kPa（2.1 - 2.4），服用卡托普利后显著增加至2.9%/0.1 kPa（2.1 - 3.2）（p＜0.05）。未观察到副作用。本研究表明总体二氧化碳反应性无变化；然而，在PaCO2静息值附近PaCO2有小变化时脑血管的二氧化碳反应性增加，且口服卡托普利后CBF与CMRO2的耦合维持不变。
