Abstract
Several specific nutrients for L line cells in a serum-free medium were reported previously from this laboratory, and they were re-examined in the present paper in detail. Surprisingly, I mM of pyruvate inhibited the growth of the cells contrary to our earlier observation. On the other hand, growth-stimulatory effect of insulin was re-confirmed in the present study and it was proved that the effect was in parallel with its hormonal action. Bovine albumin improved cell multiplication. This effect was verified to be due to albumin molecule itself, and not to possible contaminants such as various fatty acids. The role of albumin was regarded not as an attachment factor', but as a direct growth stimulant' for L cells.
