Aziz S M, Gosland M P, Crooks P A, Olson J W, Gillespie M N
Division of Pharmacology, College of Pharmacy, A.B. Chandler Medical Center, University of Kentucky, Lexington, USA.
J Pharmacol Exp Ther. 1995 Jul;274(1):181-6.
The polyamines putrescine, spermidine and spermine (SPM) are low molecular weight organic cations that play essential intracellular regulatory roles in cell growth and differentiation. Whereas both de novo polyamine synthesis and transmembrane transport regulate cell polyamine contents, exploitation of pathways as pharmacologic targets has been limited by the lack of agents which specifically block polyamine transport. We now report the synthesis and biologic activity of novel polymeric glutaraldehyde conjugates of putrescine, spermidine and SPM which act at the cell membrane to inhibit polyamine uptake in cultured bovine pulmonary artery smooth muscle cells. Each conjugate caused dose-related inhibition of [14C]polyamine transport in pulmonary artery smooth muscle cells with the polymeric SPM conjugate being most effective in inhibiting the uptake of all three polyamines. Polymeric SPM failed to impair uptake of neutral or charged amino acids or to associate with pulmonary artery smooth muscle cells in a temperature-dependent manner. The polymeric SPM conjugate caused substantial decreases in cell polyamine contents which were associated with concentration-dependent cytotoxicity. Spectroscopic analyses of the polymeric SPM conjugate indicated that its molecular weight was 25 +/- 0.5 kDa, which is equivalent to approximately 90 monomeric--HN(CH2)3NH(CH2)4NH(CH2)3NH(CH2)5--units. These findings indicate that reduced polymeric glutaraldehyde conjugates of the polyamines may function as specific inhibitors of polyamine transport and thus provide a basis for examination of polyamine transport as a pharmacologic target in disorders characterized by dysregulated cell growth and differentiation.
多胺腐胺、亚精胺和精胺（SPM）是低分子量有机阳离子，在细胞生长和分化过程中发挥着重要的细胞内调节作用。虽然多胺的从头合成和跨膜转运都能调节细胞内的多胺含量，但由于缺乏特异性阻断多胺转运的药物，将这些途径用作药物靶点的研究受到了限制。我们现在报告了腐胺、亚精胺和SPM新型聚合戊二醛缀合物的合成及其生物活性，这些缀合物作用于细胞膜，抑制培养的牛肺动脉平滑肌细胞对多胺的摄取。每种缀合物都能引起肺动脉平滑肌细胞中[14C]多胺转运的剂量依赖性抑制，其中聚合SPM缀合物在抑制所有三种多胺的摄取方面最为有效。聚合SPM不会损害中性或带电荷氨基酸的摄取，也不会以温度依赖的方式与肺动脉平滑肌细胞结合。聚合SPM缀合物导致细胞内多胺含量大幅下降，这与浓度依赖性细胞毒性有关。对聚合SPM缀合物的光谱分析表明，其分子量为25±0.5 kDa，约相当于90个单体——HN(CH2)3NH(CH2)4NH(CH2)3NH(CH2)5——单元。这些发现表明，多胺的还原型聚合戊二醛缀合物可能作为多胺转运的特异性抑制剂发挥作用，从而为将多胺转运作为细胞生长和分化失调相关疾病的药物靶点进行研究提供了基础。
