Effects of diethyltindichloride on amino acid and nucleoside transport in suspended rat thymocytes,

Abstract

The effects of diethyltindichloride (DETD) on basic biochemical processes of thymus cells were investigated in order to develop an understanding of the mechanism by which dialkyltins act on the thymus of rodents in vivo. Accumulation of the nonmetabolizable amino acid [alpha]-aminoisobutyrate (AIB) was markedly inhibited by the dialkyltins in suspended rat thymocytes. The inhibitory effects on AIB influx were apparent after as little as 5 min of thymocyte preincubation with DETD. Low dialkyltin concentrations, which did not inhibit AIB influx in noninsulin-stimulated cells, abolished the insulin-mediated AIB influx. Addition of lipoic acid (reduced) to the incubation medium prevented the inhibitory action of DETD on AIB influx. DETD markedly inhibited labeled thymidine incorporation into DNA of suspended rat thymocytes, possibly via inhibition of transmembrane transport of this nucleoside precursor. In sharp contrast to its effect on thymidine incorporation, DETD stimulated the incorporation of labeled uridine into RNA.