ABSTRACT
Transformation and uptake of [8-14C]-adenosine and its synthetic analog 2',3'-O-isopropylideneadenosine was studied in Zajdel hepatoma cells and their homogenates. Uptake and deamination of adenosine and 2',3'-O-isopropylideneadenosine by Zajdel hepatoma cells proceed differently. A small part of adenosine is phosphorylated and then it is included into biosynthesis of polymer substances. The uptake and deamination of 2',3'-O-isopropylideneadenosine by hepatoma cells occurs more intensively than uptake and deamination of adenosine. The formed 2',3'-O-isopropylideneadenosine is not splitted by purine nucleoside phosphorylase and is accumulated in cells in the incubation medium that lead to cell death. The same rate of 2',3'-O-isopropylideneadenosine deamination in cells and their homogenates indicates its high penetrability through plasma membranes. The high uptake of 2',3'-O-isopropylideneadenosine contrary to adenosine leads to deaggregation of cells and their destruction.
Subject(s)
Adenosine/analogs & derivatives , Adenosine/metabolism , Liver Neoplasms, Experimental/metabolism , Animals , Cells, Cultured , Purines/metabolism , Rats , Tumor Cells, Cultured/metabolismABSTRACT
Transformation of synthesized 2',3'-O-isopropylidene adenosine was studied in comparison with adenosine in rat liver homogenates. It is stated that 2',3'-O-isopropylidene adenosine is subjected to deamination similar to adenosine but less intensively. Due to deamination 2',3'-O-isopropylidene inosine is formed from 2',3'-O-isopropylidene adenosine. It is shown that under conditions of the conducted experiments enzymic splitting of the isopropylidene grouping from the preparation does not occur; this substrate contrary to adenosine does not split under the effect of purine nucleoside phosphorylase.
