Increased 5′-nucleotidase activity induced by dibutyryl cyclic AMP treatment of cultured glial cells

In an attempt to clarify the relationship between ecto-5′-nucleotidase (5′-N) activity and cell differentiation of glial cells, dibutyryl cyclic AMP (dBcAMP), which induces cell differentiation, was administrated to cultured rat glioma cells in logarithmic and confluent phases of cultivation. To evaluate the cellular differentiation, cell morphology and the number of glial fibrillary acidic protein (GFAP) positive cells were examined. Treatment with 1 mM dBcAMP decreased cell proliferation and induced cell differentiation in both the logarithmic and the confluent phases. The number of GFAP-positive cells increased with cellular aging and this tendency was enhanced by dBcAMP administration. Ecto-5′-N activity was higher in dBcAMP treated cells than in non-treated cells in both the logarithmic and the confluent phases. These findings suggest that ecto-5′-N activity of C6 glioma cells is increased by dBcAMP actions and is accompanied by cell differentiation.