Purinergic stimulation of astroblast proliferation: Guanosine and its nucleotides stimulate cell division in chick astroblasts

A highly active fraction that was mitogenic for astroblasts but which contained no amino acids was identified during the purification of peptides from chick embryo brains. This material was purified by ultracentrifugation, ultrafiltration through Diaflo PM-30 and YM-2 membranes and retention on Diaflo YC-05, followed by ion exchange chromatography and reversed phase high performance liquid chromatography (HPLC) on a C18 Deltapak column. On thin …