Seeman P
J Pharmacol Methods. 1987 Jul;17(4):347-60. doi: 10.1016/0160-5402(87)90048-9.
Since the absolute density of dopamine receptors can vary in disease, it is essential to establish the normal values for the absolute densities of D1 and D2 receptors in the brain. Absolute densities are most conveniently reported in units of picomoles per gram of original tissue, readily permitting their comparison to data obtained by positron emission tomography in patients. The density of D1 receptors is approximately 120 pmol/g in the rat striatum and 19 pmol/g in the human striatum. The density of D2 receptors is about 32 pmol/g in the rat striatum and 14 pmol/g in the human striatum, these values being determined by Teflon-glass homogenization and the centrifugation method. The customary Polytron-homogenization procedure results in a loss of about 9% of the D2 receptors in rat tissue and about 28% in human tissues; filtration results in a further loss of about 12%. There is general agreement between the in vitro and in vivo densities, but only if the receptors are measured by the amount of radioisotope specifically displaced.
由于多巴胺受体的绝对密度在疾病中可能会发生变化，因此确定大脑中D1和D2受体绝对密度的正常值至关重要。绝对密度最方便以每克原始组织皮摩尔为单位报告，这样便于将其与通过正电子发射断层扫描在患者身上获得的数据进行比较。大鼠纹状体中D1受体的密度约为120 pmol/g，人类纹状体中为19 pmol/g。大鼠纹状体中D2受体的密度约为32 pmol/g，人类纹状体中为14 pmol/g，这些值是通过聚四氟乙烯-玻璃匀浆法和离心法测定的。常规的Polytron匀浆程序会导致大鼠组织中约9%的D2受体丢失，人类组织中约28%的D2受体丢失；过滤会导致进一步约12%的丢失。体外和体内密度之间总体上是一致的，但前提是受体通过特异性置换的放射性同位素量来测量。
