黄夹次甙甲和甙乙的放射免疫测定及其药代动力学

用次甙甲-牛血清白蛋白复合物免疫家兔制备了亲合力强,特导性高的抗体,建立了放射免疫测定法。竞争实验表明:抗次甙甲血清与次甙乙的交叉反应为100%,单乙酰次甙乙20%,地高辛0.4%,皮质酮<0.2%,对次甙乙的敏感度至少0.3ng。静注次甙甲和乙的血浆浓度-时间曲线符合二室开放模型。次甙乙的T_1/2α=11min,T_1/2β=6.79 h,次甙甲则分别为8min和2.13h,口服次甙甲,乙和黄央甙后血浆峰浓度时间分别为52,34及15min,生物利用度分别为29.5、35.6及27.1%。

THE RADIOIMMUNOASSAY AND THE PHARMACOKINETICS OF PERUVOSIDE AND NERIIFOLIN

Antibodies with high affinity and specificity were produced by six-month immunization of rabbits with BSA-peruvoside conjugate emulsified wit Freunds adjuvant. The titer of the antisera was measured to be 800 when using ³H-neriifolin (1 Ci/mmol) as the labelled antigen. Competition experiments showed that cross-reaction of the antiperuvoside sera with neriifolin was complete, but was little with cerberin (20%), digoxin (0.4%) and corticosterone (<0.2%). Sensitivity of the method in measuring neriifolin was at least 0.3 ng. The coefficients of variance within-assay and between-assays were 5.2～6.5% and 5.1～10.7%, respectively.After intravenous injection of peruvoside or neriifolin, the plasma concentration-time curve was shown to fit a two compartment open model with the following pharmacokinetic parameters: neriifolin T1/2α=11 min, T1/2β=6.79 h, vd=6.78 L/kg and CL=0.69 L/h/kg; peruvoside T1/2α=8 min, T1/2β=2.13 h, vd=3.94 L/kg and CL=1.28 L/h/kg. After oral administration of peruvoside, neriifolin and neriperside, absorption was shown to be rapid with peak blood levels at 52 min, 34 min and 15 min respectively. The bioavailability of peruvoside, neriifolin and neriperside was found to be 29.5%, 35.6% and 27.1% respectively.