谷氨酸脱羧酶放射测量法的改良及应用

Improvement of Glutamic Decarboxylase Radioassay and Its Apply

用NaOH代替苯乙胺作为14 CO2 的吸附剂 ,改进谷氨酸脱羧酶 (GAD)活性的放射测定方法 ,结果发现NaOH为吸附剂组内变异系数为 9 6 % ,以苯乙胺为吸附剂组内变异系数为 31 9% ;以NaOH为吸附剂 72h后测量其放射活性仍稳定不变 ,以苯乙胺为吸附剂者 1h后放射性活性即下降 47% ,6h后已降低至本底水平 ;14 CO2 重吸收实验亦证明以苯乙胺为吸附剂吸附的14 CO2 6h内已有 80 %以上重新被NaOH吸附 ;以NaOH作为吸附剂测定GAD的活性 ,在 0 39～ 17 8mg脑组织样品范围内GAD量与14 CO2 生成量之间有线性关系 .NaOH代替苯乙胺作为14 CO2 的吸附剂测定GAD的活性其灵敏度提高 1 6 6倍 .用此方法测定组织和细胞内GAD活性证明其具有良好的重复性和稳定性 ,值得推广应用 .

The radioassay of glutamic decarboxylase(GAD) was modified by taking NaOH as trapped agent instead of phenylethylamine. The results showed that the coefficient of variation ( CV ) within same sample was 9 6% and the radioactivity remains stable after 72 hours if use NaOH as trap agent. It is significantly stable than use phenylethylamine as trap agent, which the CV was 31 9% and the radioactivity decreased 47% within the first hour and decreased to background after 6 hours. The reabsorption experiment shows over 80% of 14 CO 2 can be reabsorption by NaOH within 6 hours. It is suggested that NaOH is a much better trap agent than phenylethylamine and the sensitivity can increase 1 66 folds. Using this method the GAD activity in 0 39～17 8 mg of brain tissue can be measured and it is success in determine the GAD activity both in rat brain tissue and cultured neurons.