Abstract
Addition of 1 .mu.M l-norepinephrine to cultures of C6TK- rat glioma cells caused a 2-fold increase in specific activity of the glial-specific enzyme 2'':3''-cyclic nucleotide 3''-phosphohydrolase (nucleoside-2'':3''-cyclic-phosphate 3''-nucleotidohydrolase, EC 3.1.4.16). Specific activity could also be stimulated by analogs of cyclic[c]AMP, and the effect of norepinephrine could be blocked by .beta.-adrenergic receptor antagonists but not by .alpha.-adrenergic antagonists. Norepinephrine or cAMP analogs also increased the specific activity of this enzyme in other clones of glioma and Schwannoma cells and in glioma .times. neuroblastoma cell hybrids. The stimulatory effect of norepinephrine on cAMP concentrations in glioma cells leads to a stimulation of glial-specific cell function.