ACETYLCHOLINE ACCUMULATION AND RELEASE BY HYBRID NG108-15, GLIOMA ANDNEUROBLASTOMA-CELLS - ROLE OF A 16 KDA MEMBRANE-PROTEIN IN RELEASE

A procedure is described to fill up cells in culture with ACh and stud y its calcium dependent release, by-passing the synthesis steps. Wheth er differentiated or not with dbc-AMP, the NG108-15 cells efficiently released ACh when stimulated with calcium and ionophore A23187. The re lease was also studied in the parent C6-BU-1 and N18TG2 cells. It was found that C6-BU-1 released ACh much better that N18TG2 in spite of th eir glial origin. The internalization by NG108-15 cells of an antisens e oligonucleotide probe hybridizing the 16 kDa proteolipid messenger c ommon to mediatophore and to the V-ATPase reduced ACh release indicate d a role of this proteolipid in ACh translocation. This characteristic protein was found in the membrane extract of NG108-15 cells and also in the C6-BU-1 cells, but its amount was strongly reduced in the N18TG 2 cell line and in the NG108-15 cells having internalized the antisens e probe.