Hansen T D, Warner D S, Todd M M, Vust L J, Trawick D C
Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City 52242.
Anesthesiology. 1988 Sep;69(3):332-7. doi: 10.1097/00000542-198809000-00008.
The effects of halothane versus isoflurane on distribution of cerebral blood flow (CBF) were compared using 14C-iodoantipyrine autoradiography. Sprague-Dawley rats were exposed to 1 MAC of either halothane (n = 8) or isoflurane (n = 7) in 33% O2/balance nitrogen for 55 min prior to determination of CBF. Normoxia, normothermia, and normocapnia were maintained throughout the experiment and arterial pressures (MAP) were held within the range of 90-100 mmHg by infusion of blood. Coronal autoradiographic brain images were then digitized and optical density values converted to CBF with the use of 14C autoradiographic standards and arterial radioactivity data. Hemispheric, neocortical, subcortical, and selected local anatomical regions were defined on a cathode ray screen display by cursor outline. Mean CBF for each region was determined at each of eight standardized coronal brain sections, and area weighted average values for the whole brain were also calculated. Hemispheric CBF was identical in the two anesthetic groups: halothane = 150 +/- 16 ml.100 gm-1.min-1; isoflurane = 147 +/- 19 ml.100 gm-1.min-1. However, neocortical CBF was greater in halothane anesthetized animals (halothane = 185 +/- 16 ml.100 gm-1.min-1; isoflurane = 154 +/- 19 ml.100 gm-1.min-1, P = .004). The authors conclude that halothane and isoflurane exert regionally selective effects on CBF with halothane appearing to have a more pronounced effect on the neocortex. Previously reported discrepancies concerning the relative effects of these two agents on CBF may be due to inherent differences in the tissue regions measured by the different techniques.
采用¹⁴C - 碘安替比林放射自显影术比较了氟烷与异氟烷对脑血流量（CBF）分布的影响。在测定CBF之前，将斯普拉格 - 道利大鼠置于含33%氧气/其余为氮气的环境中，分别暴露于1个最低肺泡有效浓度（MAC）的氟烷（n = 8）或异氟烷（n = 7）中55分钟。在整个实验过程中维持正常氧合、正常体温和正常二氧化碳分压，并通过输血使动脉血压（MAP）保持在90 - 100 mmHg范围内。然后将冠状位脑放射自显影图像数字化，并利用¹⁴C放射自显影标准和动脉放射性数据将光密度值转换为CBF。通过光标轮廓在阴极射线屏幕显示器上定义半球、新皮质、皮质下及选定的局部解剖区域。在八个标准化冠状脑切片的每一个上测定每个区域的平均CBF，并计算全脑的面积加权平均值。两个麻醉组的半球CBF相同：氟烷组 = 150 ± 16 ml·100 g⁻¹·min⁻¹；异氟烷组 = 147 ± 19 ml·100 g⁻¹·min⁻¹。然而，氟烷麻醉的动物新皮质CBF更高（氟烷组 = 185 ± 16 ml·100 g⁻¹·min⁻¹；异氟烷组 = 154 ± 19 ml·100 g⁻¹·min⁻¹，P = .004）。作者得出结论，氟烷和异氟烷对CBF具有区域选择性作用，氟烷对新皮质的作用似乎更明显。先前报道的关于这两种药物对CBF相对作用的差异可能是由于不同技术所测量的组织区域存在固有差异。
