^(125)碘-眼镜蛇心脏毒素在大、小白鼠体内过程

DISPOSITION OF ^(125)1-CARDIOTOXIN FROM COBRA VENOM IN MICE AND RATS

用Iodogen氧化^(125)碘标记眼镜蛇心脏毒素(CTX)。大白鼠舌下静脉注射^(125)I-CTX后体内过程符合开放二房室模型,t1/2α为0.38h,t1/2β为16.59h,Vd=183.8ml/kg,Cl=14.15ml/kg·h。大白鼠皮下注射^(125)I-CTX后1h血浓度达高峰。小白鼠尾静脉注射示踪剂量的^(125)I-CTX后在各组织内分布不均,0.5h时肾脏内放射性强度占总计数的38.47％,肝30.86％,脾13.18％,心肌3.64％,脑0.57％,提示^(125)I-CTX不易透过血脑屏障。24h动态观察,各器官内放射性强度逐渐下降,说明CTX与组织的结合是可逆的。小白鼠尾静脉注射致死剂量^(125)I-CTX后,肾脏放射性分布最高,心、肝、脾差异不大,分别占总计数的9.19％、15.34％及9.88％,心脏内的分布增加。说明CTX与组织的结合有选择性,其致死原因与在心脏内的选择性浓集有关。

Using 125I-catdiotcxin (125I-CTX), pharmacokinetic studies were done OR rats and mice. By intravenous injection into rats, it appeared as two compartmental model with . Absorption after subcutaneous administration was quite complete and time to peak plasma level was found to be 1 h. Tissue distribution and subsequent decay were studied in mice, the amount of radioactivity of tracer dose was found higher in kidneys, liver, spleen and Jungs but only trace in the brain and declined gradually without evidence of redistribution. In case of lethal dose, the radioactivity in kidneys and heart was much higher. The results show wide tissue distribution, reversible tissue binding and relative selective cardiac toxicity of the CTX.