Comparison of measurements of local brain blood flow by hydrogen clearance with the inhalation of hydrogen and its electrochemical generation in brain tissue.
Comparison of measurements of local brain blood flow by hydrogen clearance with the inhalation of hydrogen and its electrochemical generation in brain tissue.
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通过氢气清除法测量局部脑血流量与吸入氢气及其在脑组织中的电化学产生的比较。
DOI：
10.1007/bf02360689
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发表时间：
1996
影响因子：
--
通讯作者：
Malysheva,NG
中科院分区：
文献类型：
--
作者：
MoskalenkoYuE;Rovainen,C;Woolsey,TA;Wei,L;Lui,D;Spence,ME;Semernia,VN;Weinstein,GB;Malysheva,NG
方法20多年前提出了利用氢清除技术测量局部脑血流量的方法，该技术是基于直接靠近记录电极的脑组织中的电化学产生氢来测量局部脑血流量的。然而，尽管与吸入性氢清除技术相比，这些方法相对简单，但这种研究脑血液循环的方法并没有得到广泛的接受。这在许多方面都是由这样一个事实解释的，即通过脑组织中的电化学产生氢而通过氢清除技术获得的数据包含与氢从其电化学产生的位置向周围组织自由扩散有关的极大误差。为了排除这一误差，建议在实验完成后在未灌流的大脑中测量弥散成分，然后从活体动物的测量结果中减去它。还从实验上阐明了允许最有效地使用这些方法的一些条件：找到了记录电极和产生电极之间的最佳距离和产生电流的参数[1]。这些研究总体上证明了所讨论方法的可接受性，是在慢性实验条件下进行的，在初步(研究开始前7-10天)将电极植入脑组织后进行。另一方面，在脑组织中使用使用电化学制氢的氢清除技术的具体特征并没有像应用于急性实验的条件那样进行严格的实验分析。因此，本研究旨在阐明两种氢清除技术在麻醉动物急性实验条件下脑血流量测量结果相互关系的特点。一种是吸入氢气，另一种是在脑组织中使用相同的记录电极，在引入脑组织后40分钟使用相同的记录电极，一种是吸入氢气，另一种是在脑组织中产生短暂的(几秒)电化学反应。按照[4]中描述的方法，对动物进行气管切开，并在头盖骨的躯体感觉皮质区域放置一个环状开口。未受损的硬脑膜上覆盖了一层矿物油。实验过程中，左股动脉插管监测动脉压，范围80~100 mm Hg。通过恒温卧床将直肠温度维持在38℃。然后静脉注射1 mg/kg的右旋卡林，以90~100次/min的速度和1.25cm3的通气量转入人工呼吸机。呼出空气中的二氧化碳浓度维持在4.0%水平。
Methods using the hydrogen clearance technique, based on the electrochemical generation hydrogen in brain tissue directly adjacent to the recording electrode, for the measurement of local cerebral blood flow were proposed more than twenty years ago [7]. However, despite the relative simplicity of these methods as compared with the inhaled hydrogen clearance technique, this method of studying the cerebral blood circulation has not achieved widespread acceptance. This is in many respects explained by the fact that the data obtained by hydrogen clearance techniques through its electrochemical generation hydrogen in brain tissue contain a substantial error associated with flae free diffusion of hydrogen from the site of its electrochemical generation into the surrounding tissues. The measurement of the diffusional component after the completion of the experiment in the nonperfused brain and to then subtract it from the results of the measurements in the living animal was proposed in order to exclude this error [2, 6]. Some of the conditions permitting the most effective use possible of these methods have also been elucidated experimentally: the optimal distances between the recording and the generating electrodes and the parameters of the generation current were found [1]. These investigations, which demonstrated the acceptability of the methods in question overall, were carried out in chronic experimental conditions after preliminary (7-10 days before the beginning of the investigations) implantation of the electrodes into the brain tissue. On the other hand, the specific features of the use of the hydrogen clearance technique using electrochemical hydrogen generation in brain tissue have not been subjected to strict experimental analysis as applied to the conditions of an acute experiment. Therefore, the present study has been directed toward the elucidation of the specific features of the interrelationship of the results of the measurement of cerebral blood flow under the conditions of an acute experiment on anesthetized animals by means of the two modifications of the hydrogen clearance technique, one involving the inhalation of hydrogen and the other through its brief (several seconds) electrochemical generation in brain tissue, using the very same recording electrodes 40 min after they have been introduced into the brain tissue.The investigations were carried out in 39 white Wistar rats of both sexes, weighing 250-300 g, under urethane anesthesia (1 g/kg, intraperitoneally). The animal was tracheotomized and a trephined opening was placed in the skull in the region of the somatosensory cortex by the methods described in [4]. The undamaged dura mater was coated with a layer of mineral oil. The left femoral artery was catheterized for monitoring the arterial pressure, which was 80-100 mm Hg during the experiments. The rectal temperature was maintained at 38~ by means of thermostatic bedding. The animal was then injected with 1 mg/kg d-tubocurarine intravenously and the animal was transferred to artificial ventilation at a rate of 90-100 per min and a volume of 1.25 cm 3. The CO 2 concentration in the expired air was maintained at the 4.0% level.