Tsibulevskiĭ A Iu, Dubovaia T K, Deev A I, Semushin B V, Shcherbo I V
Russian State Medical University, Moscow, Russia.
Izv Akad Nauk Ser Biol. 1998 Jan-Feb(1):55-9.
In connection with the important role of serum albumins in pathogenesis and sanogenesis of numerous toxic states, we examined binding capacity of these proteins and conditions of their binding sites after acute poisoning with tetrachloromethane (TCM) and administration of antihypoxic agents (sodium gamma-hydroxybutirate), antioxidants (Dibunol), and actoprotector (Tomersol) to rats. We demonstrated that tetrachloromethane intoxication (3.2 g/kg over 24 h) was accompanied by a certain decrease (by 13.8%) in the total blood serum level of albumins and a tendency to a decrease in the value of the binding constant of negatively charged fluorescent probe 1-(phenylamino)-8-sulfonaphthalene. Under these conditions, the mean number of probe binding sites per albumin molecule increases, and as a result, the total concentration of albumin binding sites in the serum remains virtually unchanged. We found that accessibility of the probe to a quenching agent (potassium nitrate) increases in the protein--probe complex under intoxication conditions, suggesting that the type of interaction between the protein and the fluorescent probe changes as well. Therapeutic/prophylactic administration of an antioxidant, antihypoxic agent, or actoprotector leads to an increase in the level of albumin in the serum (Tomersol), partial normalization of its binding properties (binding constant in the case of sodium gamma-oxybutirate, mean number of binding sites per molecule for Dibunol and Tomersol), and the state of binding sites (sodium gamma-oxybutirate, Dibunol).
鉴于血清白蛋白在多种中毒状态的发病机制和康复过程中发挥的重要作用,我们研究了大鼠在急性四氯化碳(TCM)中毒后以及给予抗缺氧剂(γ-羟基丁酸钠)、抗氧化剂(二丁基羟基甲苯)和抗应激剂(托美索)后这些蛋白质的结合能力及其结合位点的情况。我们发现,四氯化碳中毒(24小时内给予3.2克/千克)会使血清白蛋白总水平出现一定程度的下降(下降13.8%),并且带负电荷的荧光探针1-(苯氨基)-8-磺基萘的结合常数有下降趋势。在这些情况下,每个白蛋白分子上探针结合位点的平均数增加,因此血清中白蛋白结合位点的总浓度实际上保持不变。我们还发现,在中毒条件下,蛋白质-探针复合物中探针与猝灭剂(硝酸钾)的可及性增加,这表明蛋白质与荧光探针之间的相互作用类型也发生了变化。抗氧化剂、抗缺氧剂或抗应激剂的治疗性/预防性给药会使血清中白蛋白水平升高(托美索),其结合特性部分恢复正常(γ-羟基丁酸钠的结合常数,二丁基羟基甲苯和托美索的每个分子结合位点平均数),以及结合位点状态(γ-羟基丁酸钠、二丁基羟基甲苯)。