ECTO-5'-NUCLEOTIDASE ACTIVITY IN PC-12 CELLS IS SYNERGISTICALLY MODULATED BY NERVE GROWTH-FACTOR AND 8-BROMO-CAMP

As analysed by HPLC, ecto-5'-nucleotidase activity was expressed in untreated PC12 cells and gradually was stimulated about three times during the first 12 days of treatment with NGF (50 ng/ml), i.e. during initiation of neurite outgrowth and establishment of the neuritic network. Treatment of PC12 cells with 8-Bromo cAMP (8-Br-cAMP) alone did not affect 5'-nucleotidase activity, but the simultaneous application of NGF and 8-Br-cAMP (1mM) synergistically enhanced 5'-nucleotidase activity about sixfold after 9 days of treatment already. Once the neuritic network was established ( >12 days), no further increase in enzymatic activity was observable. Thus, the ectoenzyme 5'-nucleotidase is modulated during the process of neuronal differentiation in vitro, and in addition to its enzymatic function, may play a role in cell differentiation and recognition.