Abscence of metabolic co-operation between certain types of mammalian cells in culture.

A mutant line of BHK21 cells lacking inosinic pyrophosphorylase activity (IPP~ cells) does not incorporate [*H]hypoxanthine, as opposed to wild type BHK cells. When IPP+ and IPP~ cells are grown together in the presence of [H]hypoxanthine, IPP~ cells in contact with IPP+ cells incorporate the marker, as seen by autoradiography. This phenomenon is known as 'metabolic co-operation'. In the present work no co-operation was detected between wild type BHK cells and BHK cells lacking thymidine kinase activity (TK~ cells they do not incorporate [*H]thymidine); between wild type L cells and L-TK~ cells, or between L cells and L-IPP" cells. And there is no interaction in mixed cultures of mast cells and mast-cells-IPP~.