Time-dependent uptake of [(11)C]SA4503 was measured in the brain of young (1.5 to 3 months) and aged (18 to 32 months) Wistar Hannover rats, and tracer-kinetic models were fitted to this data, using metabolite-corrected plasma radioactivity as input function.
In aged animals, the injected probe was less rapidly metabolized and cleared. Logan graphical analysis and a 2-tissue compartment model (2-TCM) fit indicated changes of total distribution volume (V T) and binding potential (BP ND) of the tracer. BP ND was reduced particularly in the (hypo)thalamus, pons, and medulla.
Some areas showed reductions of ligand binding with aging whereas binding in other areas (cortex) was not significantly affected.
在年轻(1.5至3个月)和老年(18至32个月)WistarHannover大鼠的大脑中测量[(11)C]SA4503的时间依赖性摄取,示踪剂动力学模型与这些数据拟合,使用代谢物校正的血浆放射性作为输入函数。
在老年动物中,注射的探针代谢和清除速度较慢。Logan图形分析和2组织区室模型(2-TCM)拟合表明示踪剂的总分布体积(VT)和结合电位(BPND)的变化。BPND降低,特别是在(下)丘脑,pons,还有髓质.
一些区域显示配体结合随老化而减少,而其他区域(皮质)中的结合没有显著影响。