Incorporation of adenosine into nucleotides of chromaffin cells maintained in primary cultures.

Extracellular adenosine was incorporated into nucleotides of bovine chromaffin cells maintained in primary culture. In intact chromaffin tissue, a very low incorporation was found (0.8 pmol/10(6) cells/h at an adenosine concentration of 11.45 ?M), which increased 282 times in freshly isolated chromaffin cells. When maintained in primary culture, this value decreased to a value similar to that of chromaffin tissue, but later on, and in the presence of nerve growth factor (NGF), a time dependent increase of adenosine incorporation was observed which, in 84-h old cells reached up to 54 times more than that found in intact tissue. This incorporation might reflect changes in the adenosine transport at the cell membrane level, furthered by NGF effect. Incorporation, which was time-dependent, was weakly modified by stimulation of cells with 10(?4) M acetylcholine. However, acetylcholine-induced release of labelled nucleotides from chromaffin granules was observed, probably in relation to granule maturation.