鲮鱼对食物和水中110mAg的吸收和排泄

鲮鱼鱼苗摄食110mAg标记的人工饵料后排出十分快速 ,摄食 2 4h至第 7d后 ,鱼整体的放射性迅速降低约为 0h的 2 .62 % ,110mAg在鱼体内的分布很不均匀 ,其分布的比活度次序为肝>肠 >胆 >眼 >鳃 >剩余 >肌肉 ,肝脏、肠和胆最高 ,各占总体的 48.1 4% ,1 8.43.%和 1 5 .4%。110mAg从水中进入鱼体内的浓集系数 (CF)随积累时间的延长而上升 ,至第 1 3d上升为 2 0 8.6。排出速率相对于从食物途径的较为缓慢 ,第 1 5～ 2 8d后体内的放射性活度为 0h的 2 0 .1 %和1 6.7%。排出过程分为快相和慢相 ,0～ 2d内为快相 ,2d后为慢相 ,慢相的生物半排出期为2 2d。在积累和排泄期间110mAg在鱼体内的分布也主要积累在内脏 ,均约占总活度的 80 %。

UPTAKE AND EXCRETION OF ~(110m )Ag BY MUD CARP Cirrhina molitorella

Accumulation,excretion and tissue distribution of 110m Ag from both labeled food and water pathways in juvenile mud carp Cirrhina molitorella were investigated. Results indicated that the excretion rate of 110m Ag uptaken from artificial food pathway was very fast. 24 hours after feeding, the radioactivity of the fish decreased rapidly to 2.62% of the initial one and maintained the similar level afterwards in the 7 days excretion experiment. On the 7th day of excretion, the fish were dissected to separate the organs and tissues. The distribution of 110m Ag in the fish was uneven. Radioactivity of 110m Ag in the organs and tissues was in the order as liver>intestine >gall bladder>eye>gill>remainder>muscle. The radioactivity in liver, intestine and gall bladder were 48.14%,18.43% and 15.43% of the total radioactivity of the fish, respectively.The accumulation of waterborne 110m Ag by mud carp showed that 110m Ag was easy to be uptaken by the fish. The concentration factors at 8th hour and 13th day were 23.8 and 208.6 respectively. Excretion of 110m Ag uptaken from water pathway was slower than that from food pathway. The radioactivity decreased to 20.1% and 16.7% on 15th and 28th day, respectively. The excretion procedure was composed of fast excretion phase (0～2d) and slow excretion phase (2～28d). The half-life of 110m Ag in mud carp in the slow excretion phase was 22d during the slow excretion phase. The distribution of 110m Ag in organs and tissues was mainly in viscera, which accounted for about 80% of the total radioactivity of the fish.