The uptake of [2-14C]-methylglyoxal, a glucose metabolite, and its possible oxidation to carbon dioxide (CO2) were investigated in cultured A-10 vascular smooth muscle cells. A-10 cells bound and took up [2-14C]-methylglyoxal in a concentration-dependent manner. The uptake of [2-14C]-methylglyoxal was a rapid process, it was already detectable in the cells after 5 min of incubation, reaching a plateau by 30 min of incubation. The presence of fetal bovine serum in the incubation medium hampered the uptake of [2-14C]-methylglyoxal, suggesting an interaction between proteins and the α-oxoaldehyde. After an incubation longer than 60 min a loss of cell bound radioacticvity was detected which, as it turned out in separate experiments, was mainly due to CO2 formation from the α-oxoaldehyde. These results suggest that the generation of CO2 from methylglyoxal may be substantial in cultured cells and that methylglyoxal may contribute to the energy production below intracellular concentrations under a certain limit. In A-10 cells, this limit proved to be 300 μM, since above this concentration of methylglyoxal cell damage occurred.
Key words: methylglyoxal, vascular smooth muscle cells, Trypan blue, carbon dioxide,
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