TOXICO-KINETICS OF ACONITE ALKALOID IN VIVO

乌头碱是毒性最大的生物碱之一，然而，其药代动力学在很大程度上尚不清楚，主要是由于难以定量分析血液和尿液等生物材料中的毒素。最近，Mizugaki等人（Eisei Kagaku，34，359 - 365，1988）将使用GC-MS的选择离子监测方法应用于毒素的定量测定。本研究的目的是通过测定生物样品中乌头碱的含量来研究乌头碱的毒代动力学。用选择离子监测法对生物样品中的乌头碱进行定量测定，虽然耗时近一年，但结果令人满意。采用ICR品系雄性小鼠（体重30-35 g）进行动物实验，用次乌头碱作内标，提高了乌头碱分析的准确度。Sigma Chemical Co.溶于0.1M醋酸盐缓冲液（pH 5.0），并将小鼠腹膜内注射 ...更多信息 小鼠<50>腹腔注射乌头碱的LD_（50）为0.308mg/kg。分别于给药后5、15、30、45、60和120 min通过颈椎脱臼处死小鼠（n=3），并从心脏收集血液样品。乌头碱0.3mg/kg时，血药浓度在15 min达最大值17.2ng/ml，120 min后逐渐下降至5.63ng/ml，0.35mg/kg时，血药浓度在0.3mg/kg时达到最大值32.1ng/ml，与0.3mg/kg时同时达到最大值。乌头碱血药浓度与给药后时间的对数关系曲线显示，两种剂量乌头碱血药消除均在30 min后呈线性关系。由曲线<el>计算出0.3mg/kg和0.35mg/kg剂量下的消除速率常数（K_ s）分别为0.00718 /min和0.00835 /min，消除半衰期（T_（1/2））分别为96.5min和83.0min。总之，我们揭示了乌头碱的消除速度与两种剂量下的血药浓度成正比。我们先前报道，在小鼠中，当乌头碱剂量为0.4 mg/kg时，通过共同施用河豚毒素（0.01 mg/kg），作为乌头碱在可兴奋膜钠通道中的拮抗剂，死亡时间被延迟（Y.OHNO et al.，东北实验医学杂志，167，155 - 158，1992）。然而，在本研究中，在乌头碱剂量为0.3 mg/kg和0/35 mg/kg时，同时给予河豚毒素（0.01 mg/kg）并未延迟死亡时间。因此，在连续的研究中，两种毒素在体内的相互作用必须通过不同剂量的两种毒素的组合来检查。少

Aconitine is one of the most toxic alkaloids, however, the pharmacokinetics is largely unknown mainly due to the difficulty in quantitative analysis of the toxin from biological materials, such as blood and urine. Recently, a Selected Ion Monitoring Method using GC-MS has been applied to the quantitative determination of the toxin by Mizugaki et al. (Eisei Kagaku, 34,359-365,1988). The purpose of this study is to investigate the toxico-kinetics of aconitine by measuring it in the biological specimens. By using the Selected Ion Monitoring Method, we have gotten the satisfactory results of quantitative determination of aconitine from the biological specimens, though we costed almost a year. Moreover, we improved the more accurate analysis of aconitine by using hypaconitine as the internal standard.Male mice of ICR strain weighing 30-35 g were used for animal experiments. Aconitine (Sigma Chemical Co.) was dissolved in a 0.1 M acetate buffer (pH 5.0), and mice were injected intraperitenea … More lly with the toxin at the doses of 0.3 or 0.35 mg/kg (LD_<50> of aconitine for mice is known to be 0.308mg/kg i.p.). The mice were killed by cervical dislocation at 5,15,30,45,60, and 120 min after the administration (n=3, respectively), and blood samples were collected from the heart. At a dose of 0.3 mg/kg of aconitine, the blood concentration reached to the maximum, 17.2 ng/ml, at 15min, and decreased logarithmically to 5.63 ng/ml at 120 min. At a dose of 0.35 mg/kg of aconitine, the blood concentration reached to the maximum, 32.1 ng/ml, at the same time as the 0.3 mg/kg dose, and decreased to 10.7 ng/ml at 120 min. By plotting the blood concentrations of aconitine in logaritmic scale against the time after administration, the linear curves of the blood aconitine elimination were obtained after 30 min at both doses. From the curves the elimination velocity constants (K_<el>s) were calculated to be 0.00718 /min and 0.00835 /min, and the elimination half-time (T_<1/2>s) were to be 96.5 min and 83.0 min at doses of 0.3 mg/kg and 0.35 mg/kg, respectively. In conclusion, we revealed that the elimination velocity of aconitine is proportional to the blood concentration at the both doses.We previously reported in mice that the time of death at a dose of 0.4 mg/kg of aconitine was delayd by coadministration of tetrodotoxin (0.01 mg/kg), as antagonist of aconitine in the sodium channel in the exitable membranes (Y.OHNO et al., Tohoku J.Exp.Med., 167,155-158,1992). In this study, however, coadministration of tetrodotoxin (0.01 mg/kg) did not delay the time of death at doses of 0.3 mg/kg and 0/35 mg/kg of aconitine. So, on the continueous studies, the interactions of the two toxins in vivo have to be examined with combinations of various doses of the two toxins. Less