Toninello A, Di Lisa F, Siliprandi D, Siliprandi N
Arch Biochem Biophys. 1986 Mar;245(2):363-8. doi: 10.1016/0003-9861(86)90227-4.
Spermine, at concentrations similar to those normally present in the cytosol of liver cells, facilitates the transport of phosphate into mitochondria and thus its accumulation within the matrix space. Both mersalyl and N-ethylmaleimide (NEM) inhibit phosphate influx either in the absence or in the presence of spermine. These inhibitors also inhibit, but only partially, the efflux from mitochondria of phosphate generated within the matrix space by the hydrolysis of ATP induced by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) or the valinomycin-K+ system. The inhibition of phosphate efflux by both mersalyl and NEM is almost completely removed, unlike that of phosphate influx, by spermine. The possibility that spermine may induce phosphate efflux by damaging mitochondrial membranes and consequently inducing an unspecific permeability to phosphate is excluded by the full restoration of transmembrane potential once FCCP has been removed by albumin. Since spermine does not react with either thiol groups or thiol group reagents, the simplest explanation of the reported results is that the pathway of phosphate efflux is distinct from that of phosphate influx.
精胺在浓度与正常肝细胞胞质溶胶中相似时，可促进磷酸盐向线粒体的转运，从而使其在基质空间内积累。不管有无精胺存在，汞撒利和N - 乙基马来酰亚胺（NEM）均会抑制磷酸盐内流。这些抑制剂也会抑制，但只是部分抑制，由羰基氰对三氟甲氧基苯腙（FCCP）或缬氨霉素 - K⁺系统诱导的ATP水解在基质空间内产生的磷酸盐从线粒体的外流。与磷酸盐内流不同，精胺几乎完全消除了汞撒利和NEM对磷酸盐外流的抑制作用。一旦用白蛋白去除FCCP后跨膜电位完全恢复，就排除了精胺可能通过损伤线粒体膜从而诱导对磷酸盐产生非特异性通透性而导致磷酸盐外流的可能性。由于精胺不与巯基或巯基试剂发生反应，对所报道结果最简单的解释是磷酸盐外流途径与磷酸盐内流途径不同。
