同位素示踪法研究^(125)Ⅰ-NGF在小鼠体内的吸收、分布及排泄

Study on absorption distribution and elimination of nerve growth factor in mice by radioactivity isotope tracing method

本文应用放射性同位素示踪法与电泳分离法相结合的方法研究125I-NGF在小鼠体内的吸收、分布和排泄。结果显示:静脉注射和肌肉注射125I-NGF在小鼠体内的代谢规律均符合二房室开放模型。肌肉注射10μg/kg,20μg/kg,40μg/kg 3个剂量达峰时间分别为0.71h,1.66h,3.78h;峰浓度分别为1.74ng/mL,2.82ng/mL,4.23ng/mL;曲线所围面积分别为8.44μg/h/L,21.6μg/h/L,43.12μg/h/L,消除相半衰期分别为4.83h,4.49h,4.43h。肌肉注射10μg/kg125I-NGF生物利用度为52.7%。静脉注射125I-NGF 10μg/kg,分布相半衰期为0.13h,消除相半衰期为3.68h,表观分布容积为0.697L/kg,曲线所围面积为16.01μg/h/L。125I-NGF在所测的14种组织中均有分布,其中肾、胃、肠中放射性浓度最高,脑和脊髓最少。肌肉注射125I-NGF主要随尿液排出体外。

The study concerns in absorption distribution and elimination of nerve growth factor （NGF） in mice. 125I-NGF concentration in plasma in mice was determinated with the method of combination of sodium dodecylsulfatepoly accrylamide gel electrophoresis （SDS PAGE） and radioactivity isotope trace. Result demonstrate the time 125I-NGF concentration in plasma curve after iv or im fit a two compartment open model. After iv injection 10 /ag/kg of 1251-NGF, Distribution phase half life is 0.13h, Elimination phase half life is 3.68h, Apparent volume of distribution is 0.697 k/kg, Area under curve is 16.012 pg/h/L. After im injection of 10gg/kg, 20gg/kg, 40ug/kg of 1251-NGF, Time of peak is 0.7lb, 1.66h, 3.78h respectively; Concentration of peak is 1.74ng/mL, 2.82ng/mL, 4.23 ng/mL respectively; Area under curve is 8.44ug/h/L, 21.6ug/h/L, 43.12pg/h/L respectively; Elimination phase half life is 4.83h, 4.49h, 4.43h respectively. After im injection 10pg/kg of 1251-NGF, Bio availability is 52%. There are the most radioactivity intensity in kidney, stomach, intestines, but the weakest radioactivity intensity in brain, spinal cord. The elimination of 125I-NGF in urine is major way in mice after im injection of 125I-NGF.