静脉注射后纳米羟基磷灰石颗粒在小鼠体内的分布特性

研究了纳米羟基磷灰石（nano-HAP）颗粒静脉注射后在小鼠体内的分布、蓄积和排泄情况。将中子活化的nano-HAP尾静脉注射到小鼠体内，剂量为9mg／kg。分别在15min、1h、2h、4h、8h、24h、72h时断髓处死动物，解剖并收集动物的血液、脑、心、肝、脾、肺、肾、胃、小肠、胸骨、子宫或睾丸、粪便和尿液。用高氯酸和双氧水将收集的样品消解后，通过液体闪烁计数器测定各脏器组织和排泄物中的^45Caβ射线计数来反映nano-HAP在动物体内的分布。结果显示，尾静脉注射nano—HAP后，大部分组织中^45Caβ射线计数范围为0．5～250Counts／min·mg，肺、肝、脾这3个部位中的^45Caβ射线计数相当于其它脏器组织的6倍以上。整个试验期间，只有骨骼中的^45Caβ射线计数变化不大，其它组织中的^45Caβ射线计数均随时间延长而减少。各个时间点粪便中^45Caβ射线计数要明显大于尿液中^45Caβ射线计数。nano—HAP颗粒可以在体内大部分的器官和组织中分布，其中肺、肝、脾是nano-HAP分布最多的几个器官，而骨骼是nano-HAP唯一的蓄积器官。粪便排泄是体内nano-HAP排泄的主要途径。

Distribution of hydroxylapatite nanoparticles injected via intravenous in mouse

The present study was designed to investigate the distribution, accumulation and excretion of hydroxylapatite nanoparticles （nano-HAP） in mice with intravenous injection. The nano-HAP suspension was neutron activated and then stored 15 ld after neutron activation for experiment. The mice injected with radioactive nano-HAP heve sacrificed at 15min、 1h、 2h、 4h、 8h、 24h、 72h and the main organs were harvested for further measuring the counts of ^45Ca in every sample by use of a liquid scintillation counter. Results indicate that ^45Ca could be detected in all main organs （0.5-250Counts/min ·mg）, and there are more ^45Ca exist in lung, liver and spleen. The counts of ^45Ca in bone almost keep the same during the whole experiment period while counts of ^45Ca of all other tissues decrease with time. And the counts of ^45Ca exerted in faeces are higher than that in urine. So we can conclude that nano-HAP distribute in all organs of mice especially in lung, liver and spleen. But bone is the only tissue in which nano-HAP accumulated. Nano-HAP was excreted mostly through faeces.