Litton J E, Neiman J, Pauli S, Farde L, Hindmarsh T, Halldin C, Sedvall G
Department of Psychiatry and Psychology, Karolinska Institute, Stockholm, Sweden.
Psychiatry Res. 1993 Apr;50(1):1-13. doi: 10.1016/0925-4927(93)90019-e.
Benzodiazepine (BZ) receptor binding in the brain was determined in five chronic alcohol-dependent men and in five healthy male control subjects using [11C]flumazenil (Ro 15-1788) and positron emission tomography (PET). Magnetic resonance imaging was used to evaluate brain anatomy and pathology, and to define regions of interest in the brain. [11C]Flumazenil binding was quantified by applying a saturation procedure with two PET experiments, the first with high (400-3400 Ci/mmol) and the second with low (approximately 1 Ci/mmol) specific radioactivity. Radioactivity in the pons was taken as an estimate of free and nonspecifically bound radioligand. Equilibrium was defined to prevail when the derivative of specific binding (dCb(t)/dt) was equal to zero. The values were used in a Scatchard analysis for determination of the maximum density of binding sites (Bmax) and the equilibrium binding constant (Kd). The mean values of Bmax and Kd were about the same in the two groups, but the Bmax variance for the alcoholics was significantly greater for all regions of interest as compared with the healthy volunteers. The results may indicate that chronic alcohol consumption has multiple effects on the BZ receptor complex.
使用[11C]氟马西尼（Ro 15 - 1788）和正电子发射断层扫描（PET）技术，对5名慢性酒精依赖男性和5名健康男性对照受试者的大脑中苯二氮䓬（BZ）受体结合情况进行了测定。利用磁共振成像评估大脑解剖结构和病理情况，并确定大脑中的感兴趣区域。通过两个PET实验采用饱和程序对[11C]氟马西尼结合进行定量，第一个实验使用高比放射性（400 - 3400 Ci/mmol），第二个实验使用低比放射性（约1 Ci/mmol）。将脑桥中的放射性作为游离和非特异性结合放射性配体的估计值。当特异性结合的导数（dCb(t)/dt）等于零时，定义达到平衡。这些值用于Scatchard分析，以确定结合位点的最大密度（Bmax）和平衡结合常数（Kd）。两组的Bmax和Kd平均值大致相同，但与健康志愿者相比，酒精依赖者所有感兴趣区域的Bmax方差显著更大。结果可能表明，长期饮酒对BZ受体复合物有多种影响。
